Commit Graph
125 Commits
Author SHA1 Message Date
AnachronautandClaude Opus 5 8fbbeb6ec9 Make xfail compare the diagnostic, not just the failure
The Test Manual said an xfail test records the assembler's refusal message and so
catches both an error that stops being detected and a message that changes without
anybody meaning it to. It did not. run.sh checked only that the assembler exited
non zero, printed the first line for a person to read, and compared nothing; --bless
recorded nothing for these sixteen tests at all.

So an xfail passed four different ways that look identical from outside: the intended
error fired, an unrelated error fired, the message changed, or the assembler fell over
on its way to the point. That is the documentation describing behaviour the code does
not have, which is the exact failure Tests/docs.sh exists to prevent, in the manual
that argues for knowing what your evidence is worth.

The diagnostic is now stripped of colour, given the same [exit N] line every other
recorded result carries, and compared through check() like anything else. Sixteen
results recorded; every existing one is byte for byte unchanged. Verified the way the
manual asks: one diagnostic was broken on purpose, its test failed with the changed
line in the diff, and its neighbour passed.

Found by ChatGPT reviewing the manual.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-28 18:07:35 -04:00
AnachronautandClaude Opus 5 d6bc416698 Write the Test Manual, and make the suite check it
The test system had grown to seven scripts making five genuinely different
kinds of claim, and nothing said which was which. A recorded transcript and a
byte-for-byte comparison against a second implementation both print [ok  ] and
are worth wildly different amounts, so the fourth manual exists to say so: what
each script can and cannot answer, why every determinism rule is there, how to
add a test, and - the part written nowhere else - where the suite is blind.

That last section is the reason for the document. Three buffer overruns into
adjacent variables were all found by a person using the machine and none by the
suite, the sanitizers cannot see them because emulated Data Memory is one
legitimate host array, and there is no second opinion about the CPU at all. A
document listing only strengths teaches the wrong lesson.

The bullets describing each script move out of the README, so docs.sh now reads
the manual for them, and five more numbers in it are settled from the source
rather than trusted: the shape of the manifest, the xfail count, how many
fixture disks makedisks.sh builds, how large the lint baseline is, and the tool
count in either document. Each of the new checks was broken on purpose and
watched to report before being kept, which is the discipline the manual itself
argues for.

Also drops the stale "70 instructions" from instructiontable.py's docstring.
There are 72, and a number that carries no meaning is better removed than
corrected.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-27 23:52:12 -04:00
Anachronaut 79727044b7 Reboot, and the machine device that makes it possible
Until now the only way to restart was to stop the emulator and run it
again, which meant the one thing the machine could not do was the thing
Once was written for. The loop now closes without leaving it:

  > Once /System/Boot/bare.bin
  next start: /System/Boot/bare.bin, once
  > Reboot
  starting again
  stage two
  just this once: /System/Boot/bare.bin
  bare metal: no system, just this

Writing 1 to port 0x13 asks the machine to start over. A PORT RATHER THAN A
SERVICE, because a reset has to work when the system does not: something
only askable through SWI would be unavailable in exactly the case that
wants it most, and a program that owns the whole machine has no system to
ask. It is device class 0x04, in the range kept for the machine rather than
among the peripherals, because it is not one - it is not attached to
anything and cannot be unplugged.

WHAT A RESET REPEATS IS HOW THE MACHINE STARTED. Named an image, the
emulator places it again; named none, the ROM is shadowed again and reads
the disk. Anything else would mean a reset changed what the machine IS,
which is the one thing a reset must not do. Both are tested.

Taken between instructions, because a device cannot restart the machine
from inside the instruction that asked: the CPU is part way through a step
and its state is not yet anything a reset could leave behind consistently.

The disk stays attached and keeps everything written to it - that is what
warm means. The vector table is cleared, which is the one deliberate
departure from leaving memory alone: a vector points into whatever
installed it, and after a reset that program is not running, so a handler
left behind would aim an interrupt at an address belonging to something
gone. It is the argument CosmOS already makes at exit, applied to the
machine.

Reboot is 45 bytes, most of them the word it prints.
2026-08-27 20:56:46 -04:00
Anachronaut 7b28f48f52 Once: start something else on the next start, and only that one
A program that owns the whole machine had nowhere to run. It cannot be
started from the shell, because starting it means there is no shell, and
pointing boot.cfg at it means a machine that keeps starting it - which is a
poor place to find a mistake in something written five minutes ago.

Once writes /System/Boot/once.cfg, in the same format as boot.cfg and read
with the same routines, because a second format for one setting would be a
second format. The loader reads it before boot.cfg and DELETES IT BEFORE IT
JUMPS, which is the only moment there is: after the jump the loader does
not exist.

Consumed by being read rather than by working, so a one shot that hangs
cannot hang twice - the request is gone before the image ran, and the next
start reads boot.cfg like any other.

THE BOOT STATE IS NOT TOUCHED, and the first version got that wrong. It
marked the start the way any other start is marked, and then every
successful bare metal boot reported that it had never arrived - because a
program with the whole machine has no filesystem to clear a mark with and
is doing nothing wrong by not having one. Found by running it: the image
printed its line and the next start still said the last one did not.

Three disks, each a start further along, so none of the tests depends on
another having run.

The loop is closed on the machine now: write it in Edit, assemble it with
Asm, ask for it with Once, restart, watch it own the machine, and the
system comes back without being asked.
2026-08-27 20:02:42 -04:00
Anachronaut 89c667848b Edit read a file into a buffer it never checked the size of
Opening hello.asm showed a thirty one line file as three, one of them cut
short. Opening it again hung the machine: the emulator kept running and
nothing ever answered.

Entry is the buffer a line is read into, and it is followed in memory by
TextHead and ArenaFree - the head of the document, and the pointer its line
allocator hands out. The loop that splits a file into lines copied
characters in WITH NO BOUND AT ALL, so a 94 character line wrote thirteen
bytes over both of them. The list head then pointed into the middle of the
text and the allocator handed out an address inside the file, which is why
the second open walked a list that led back into itself for ever.

Typing was always safe. osReadLine is told how much room there is, so a new
document behaved perfectly and a source file did not - which is exactly how
the user found it, and why it looked like a mystery rather than a bug.

The bound is there now, and the buffer is 128 characters: what a line is
everywhere else on this machine, the same number configuration files use,
rather than a second answer to a question already answered. hello.asm fits.

A file with a longer line is REFUSED rather than shortened. This is an
editor - a line cut on the way in would be written back cut, and the file
damaged by having been looked at. It says so and exits with a status of
one, which it can do since this afternoon; the file is byte identical
afterwards, and the test checks that.

Opened twice in the test, because once is not enough to see it: the first
open does the damage and the second is what never returns.

This is the third time this shape has turned up: a buffer written past its
end into the variables that happened to follow it. The prompt walked off
CwdText into the shell's own command names; the assembler's output ran into
its label table. Every one was found by a person using the machine.
2026-08-27 19:41:51 -04:00
Anachronaut 87d819847e A program can say how it went
SWI osExit takes a status in A, and the shell keeps it. Fifty eight exits
across twenty three programs now say deliberately whether they worked: 25
did what they were asked, 24 did not, 9 were asked wrongly. Compare is the
exception and says so - one there means the files differ, which is a result
rather than a failure, the way diff has always had it.

IN A RATHER THAN Q, which is not a departure from the rule that a service
answers in Q. This one takes an ARGUMENT, the way osPrintNumber takes A and
B, and it never returns to answer anything. A is free precisely because a
return would have put it back - and Q is the ALU's output, so a small
number costs four instructions there against one in A.

The shell does not print it. A program that failed has already said so in
words and a number beside that is noise, so osLastStatus hands it back and
Status is the program that shows it. That indirection is the point: the
number exists for the thing that cannot read words.

MARKING THE EXITS FOUND A DEFECT ON THE FIRST RUN. Type and More printed
why they had failed and then fell through into the success exit, reporting
that all was well. Nobody had noticed, because while the only reader was a
person, the person could see both the complaint and the claim.

Two smaller things. Snake sets the console to line mode and then exits with
zero, and the linter flagged the second RSTA as redundant - an exit status
and a console mode, equal by accident, which is the class that must never
be collapsed. And the README still taught answering by writing into the
frame, three months of habit that SRET replaced yesterday; that section is
gone and the one describing SRET stands in its place.
2026-08-27 19:16:21 -04:00
Anachronaut c8c9f0b363 SRET: a handler answers the way a subroutine does
CALL saves A, B and Data Pointers 0 to 2 and nothing else, which is exactly
why Q and DP3 are how a subroutine hands something back. An interrupt saves
all of it, so a service with an answer had to reach into its own frame and
un-save two fields by hand:

  MVSD.2
  DPUP.2 0d02           ; the saved Q, by an offset it had to know
  STA.2
  RETI

Thirty places in CosmOS did that. Every one knew the frame's layout by
heart, and all thirty would have gone quietly wrong the day the frame
gained a field - the same duplicated fact this project keeps being bitten
by, except duplicated into thirty places AND into the CPU.

SRET is 0x76, in the seat the block split left for it. It is RETI's frame
with RET's rule applied: A, B and DP0 to DP2 come back, the saved Q and DP3
are dropped, and the Interrupt Flag is restored from the frame - only that
bit, so carry survives a service the way it survives a call, and there is
one rule rather than two. RETI stays exactly as it was: a hardware handler
has nothing to say and must leave no trace.

CosmOS is 10,969 bytes against 11,122, and no handler knows a frame offset.

TWO MISTAKES WORTH RECORDING, both mine, both caught by tests.

The first conversion matched STA.2 with a regular expression that did not
allow a trailing comment, so it ran past the end of one handler and into
the next. The second understood the pattern and still got it wrong: the old
frame write carried the answer from A into the saved Q slot, so simply
deleting the write left Q holding whatever it happened to hold. Services
that answer by calling something were fine - Q already had it - and
services that set A directly silently reported success for every failure.
cosmosCwd is what noticed, by saying "cannot go there" about a directory
that was there. Sixteen handlers move the answer into Q now.

Seven MVQA went with it. They copied Q into A so the frame write could
carry it; SRET puts A back, so they moved a value nobody would ever read.
2026-08-27 18:18:36 -04:00
Anachronaut cd5f548736 Move the opcode map: nothing in 0x0X, and room for a return variant
Three blocks move and nothing else changes. Branches take 0x60, subroutines
take 0x70, and the ALU moves up into the 0x10 block the two of them used to
share. Order within each block is preserved exactly - this relocates them,
it does not rethink them.

WHAT IT BUYS IS AN EMPTY 0x00 TO 0x0F. Program Memory that was never
written, or a load that stopped part way and left zeroes in its tail, used
to read as a long run of ADDs: the machine carried on through them, arrived
somewhere unpredictable, and whatever broke there was a long way from the
byte that caused it. Now it faults where it is met:

  Fault: 0x00 at Program Address 0x0004 is not an instruction.

That is the address of the byte after the last real instruction, which is
the difference between a diagnosis and a search. Reserving the whole nibble
rather than just 0x00 means a run into blank memory faults wherever it
starts rather than only when it lands on the right byte. runOffTest records
it, and the block is left empty for whatever turns out to want it.

The other half is room: branches and subroutines had filled 0x10 to 0x1F
between them, so a service return that keeps Q and DP3 had nowhere to sit
next to its family. It has 0x76 waiting now.

Five places wrote an opcode down that the scripted remap did not reach, and
four of them were found by tests rather than by looking:

- secondPass.c lists which opcodes take an address, and firstPass.c knows
  SWI by number. Missing those made XOR read as a branch.
- Asm.asm knows SWI by number too, being the other assembler. Missing it
  made the native and host assemblers disagree byte for byte, which is
  exactly the check that exists to catch a thing known in two places.
- loaderTest.asm carries a hand written payload, and its RETI was 0x19. To
  the assembler those are numbers and to the program they are data, so
  nothing but running it could notice. It says so in a comment now.
- The Assembler Manual prints the bytes hello.asm assembles to, and two of
  them were branches.

The monitor's recorded disassembly moved by exactly the bytes it should:
18 became 72 wherever SWI appears, with SETD and INIB untouched and every
disassembled line still reading the same.
2026-08-27 18:05:54 -04:00
Anachronaut ce2a2cd7e6 Settle is a program, and a machine with no fallback still starts
The boot state opened a loop that could not be closed from inside: the
machine said "settle it to try again" and gave you no way to do so. Settle
closes it, in 349 bytes.

A PROGRAM RATHER THAN A SHELL WORD. The shell is for the things that cannot
be done without it, and this is not one - it reaches the system through SWI
like anything else, which means it can be replaced, left off a disk, or
called by whatever comes to call programs in turn. That last one is the
point: a shell word is not callable by anything.

Two services for it. osBootState answers in Q, and a machine with no disk
answers settled, because there is nothing there to be unsettled about.
osBootSettle puts it back. SETTLING IS THE ONLY WRITE A PROGRAM GETS -
marking a start as trying or fallen back is the loader's business, and a
service that let a program claim either would let it lie about something
the loader has no way to check.

And a hole the tests walked into, which was mine rather than theirs. With
no fallback configured, a failed start left the machine unable to start at
all: the mark said do not use the system, and there was nothing else to
use. That turns "the last start failed" into "no start is permitted", which
is worse than the problem the mark was added to solve. With nothing to fall
back to it now tries the configuration again and says so - a failure that
was passing recovers, and one that is not leaves the machine exactly where
it would have been without any of this, which is the most that can be
promised when there is only one thing to start.

docs.sh caught both new services having no row in the services table before
anything else did.
2026-08-27 17:02:59 -04:00
Anachronaut dc74149321 B4: the disk remembers whether the last start arrived
The loader marks the superblock before it hands over and the system clears
the mark when it reaches its prompt, so a system that crashes on the way
there leaves it set. The loader finding it still set next time is how a
machine that will not start says so to the only thing in a position to do
anything about it. Without that, pointing boot.cfg at something that dies
before the shell is a machine that can never be told anything again - the
shell is the only way to change the file, and the file is what stops the
shell from starting.

Three states rather than two, and the third is the one worth having:

  0 settled    the last start arrived; use the configuration
  1 trying     handed over, and nothing came back to say it got there
  2 fell back  a try failed and the fallback was used, until settled

With only 0 and 1 the machine alternates for ever: fall back, reach a
prompt, clear the mark, retry the broken system, crash, fall back. State 2
stops that. A system known not to start is not tried again until somebody
says the situation has changed.

REACHING THE PROMPT IS A DELIBERATE THRESHOLD. It is not a claim that the
system works - a shell can be reached by something broken in every other
way. It is the point where a person can type, which is exactly what the
fallback exists to give back: anything wrong past there is fixable from the
prompt and nothing wrong before it is fixable at all.

The routines live in sbfs.asm because both the loader and the system read
and write this byte, and two pieces of code with their own idea of where a
byte lives is what this format has two implementations and a byte for byte
comparison to avoid.

And the trap this system documents in its own manual caught me anyway: the
first version handed the state back in A, which CALL restores, so every
read got whatever the caller happened to be holding. It comes back in
memory now, and the comment says why.

Three disks differing only in the state on them, so the tests read as three
consecutive starts of one machine while none depends on another running.
2026-08-27 16:51:39 -04:00
Anachronaut 546f336823 Configuration files, and boot.cfg as the first of them
One setting to a line: a key, a space, the rest of the line is the value.
A semicolon starts a comment. The format was noticed rather than designed -
textSplit already cuts the first word off a line and leaves the rest, and
textSame already insists two strings end together, so reading a setting is
those two routines and a loop. It is also what the shell reads, which makes
a configuration line a command line the machine reads instead of a person
typing one.

The format was chosen by asking what the BOOT LOADER could manage, because
it is the worst case in every direction: a few kilobytes, no operating
system to report to, and if it fails the machine does not start. Two
formats would be worse than one and the loader cannot have the richer one.

CONFIGURATION IS ADVICE. A missing file, a missing key, an unusable value,
a line too long to read: all of them mean use the default and none is a
failure. BUT QUIET IS NOT SILENT - a setting somebody meant, which did not
take effect, says so. That was the user's addition and it is the better
rule: the default alone leaves the only symptom being that the machine did
not do what somebody asked.

So two routines. cfgGet reads and says nothing, because reading three
settings should not report one bad line three times. cfgCheck reads the
file once and reports, and is handed the caller's list of keys - whether a
key means anything is the only part of this a shared reader cannot judge.

/System/Boot/ holds the boot files, and stage two reads boot.cfg for what
to start, with a fallback to try if it does not work and a name compiled in
for when the file says nothing.

THE TEST FOUND A REAL BUG, and it is the interaction I would not have
thought to look for. First-match-wins met an empty value: a file with

  system
  system /System/Boot/bare.bin

matched the first line, handed back nothing, and the machine tried to start
a file with no name while a good setting sat underneath. An unusable value
is an absent one - which is what "configuration is advice" says, and this
is where it earns its keep.

cfgBare starts an image with no operating system in it at all, which is
what loading an ordinary boot image buys: a program wanting the whole
machine is a file like any other, chosen the same way the system is. Three
disks differing ONLY in boot.cfg, so each is a test of the file rather than
of the machinery under it.
2026-08-27 16:04:21 -04:00
Anachronaut 54ff7196c9 Stage 0: the emulator carries the ROM, so a disk is enough
./SplitBit --disk system.img
  stage two
  CosmOS
  >

No boot image named. The emulator shadows its built in stage one into
Program Memory - boot vector included - and the CPU then does exactly what
it has always done: reads the boot vector and starts where it points.
NOTHING ABOUT THE CPU CHANGED to make a machine that starts itself, which
is what picking shadowing over a mapped ROM bought.

The ROM is generated from Programs/Boot/stage1.asm by the makefile rather
than committed beside it, because a copy of a program kept next to the
program is a copy that goes stale. That makes the assembler a real
dependency of the emulator, which it always sort of was and now says so.
od and awk rather than xxd, which is not everywhere, or python, which the
README does not ask anybody to install in order to build this.

loadROM is loadFile given bytes instead of a path: both go through one
reader over an fmemopen stream, because a ROM is a boot image and there is
no reason for the machine to have two ways of understanding one.

Naming an image still works and is what every other test here does. That
path is not a shortcut to apologise for - placing memory from outside is a
real thing real machines allow, and it is a debugger. The help says so now.
No image and no disk is the one case with nothing to run, and it says that
rather than printing a usage message about a missing file.

run.sh gained a "rom" mode which hands the emulator a disk and nothing
else. The source column still names stage1.asm, because that is what is IN
the ROM: assembling it there says the thing the emulator carries is a thing
that still assembles.
2026-08-27 14:41:33 -04:00
Anachronaut c312853f8e The machine starts itself
stage two
  CosmOS
  > saved it
  read it back, 22 bytes:

Stage one hands over to stage two out of a boot slot; stage two mounts the
filesystem, finds /System/cosmos.bin, takes the image apart and places its
code, its data and its vector table, and jumps to the entry point the
vectors named. Nothing placed memory for it.

What it loads is an ORDINARY BOOT IMAGE, the same SPBT file the emulator
has always been handed. That was the user's call and it is the whole trick:
a second stage that loads the machine's normal image format is not a
boot-specific mechanism, so bare metal SplitBit stops being a special case.
A program wanting no operating system under it is just an image, written
under CosmOS like any other, and startable because it is a file.

Three things in it worth knowing:

- THE ENTRY POINT IS CAUGHT ON ITS WAY PAST. Program Memory cannot be read
  back, so the boot vector cannot be looked up after being installed; the
  vector loop notices the one addressed at 0xFC00 and keeps it.
- A missing "VEC" is not a fault. An image written before vectors existed
  simply ends after its data, and then the entry point is zero, which is
  what every such image has always relied on.
- Feature flags that are set mean an image asking for a machine this may
  not be, and the honest answer to a request that cannot be understood is
  to refuse rather than to run it anyway.

The test records that the system WORKS afterwards rather than that it
started. A loaded program running is what says the vector table arrived,
because a program reaches the system through SWI and nothing else; the file
written and the directory entered say the filesystem and the console came
up with it. A second disk has a boot slot and nothing to start, and says so
rather than jumping somewhere.
2026-08-27 14:13:23 -04:00
Anachronaut 82adeeb193 A boot payload can arrange its own Data Segment
Stage one places Program Memory and nothing else, because knowing where a
payload's data ends and its code begins would mean knowing a format, and
knowing formats is what ROM must do as little of as possible. But the real
second stage needs a Data Segment: sbfs.asm has variables and a string it
compares against.

The answer needs nothing new. A loadable image is written into the slot as
code followed by data, so the data image is already in Program Memory just
past the code - and the payload's first instructions blit it down to where
it was assembled for. Proved by slotData.asm, which prints from a string it
placed itself.

The padding is the part worth recording. The blit needs a length and the
assembler will not work out the difference between two labels, so the
segment is padded to a round number and that number is what gets copied.
The first draft padded to 257 and copied 256, and the byte that did not
arrive was padding, so it worked by luck. It is exact now and says why.

This is the shape the user asked for and it goes further than the
mechanism: the second stage becomes a loader for the machine's ORDINARY
image format rather than for anything boot-specific, so bare metal SplitBit
stops being a special case. A program that wants no operating system is
just an image, developed under CosmOS like any other, and selectable at
boot because it is a file.
2026-08-27 13:45:11 -04:00
Anachronaut d07b23f90b Rung 2: the machine starts itself off a disk
Stage one exists and works. It is 330 bytes of program and everything it
knows is a thing that will be true forever: which port the disk is on, that
a SplitBit disk begins with its own name, and where two numbers sit in that
first block. Not what a file is, not what a directory is, not that SBFS has
versions. It reads the live boot slot into Program Memory, jumps to the
first byte, and prints one character and halts if there is nothing there.

It is an ordinary boot image for now, so the whole chain runs on machinery
that already exists and the emulator has not been touched. Nothing about it
changes when it moves into ROM except who puts it in memory.

SplitDisk gained "boot" to write a slot and "bootslot" to choose one, kept
apart on purpose: writing a slot and starting from it are different
decisions, and joining them would make every write a commitment. A slot is
always written WHOLE, because one still holding the tail of what was there
before is one whose contents depend on its history, and stage one reads all
of it without knowing where the file stopped.

Three recorded tests, and the pair is the point: two disks differing only
in which slot the superblock names, with payloads that say different
things. One prints "booted" and the other does not, so this is a test of
CHOOSING a slot rather than a test that some bytes were read. The third
boots a disk with no boot area and gets the one character a ROM has room
for. Eight more host checks, including that a slot is padded whole.

Two things worth recording. The first draft used #Align to put the scratch
buffer at 0x8000 and produced a 33K file - thirty two kilobytes of zeroes
in something meant to be a ROM. It is an address, not storage, which is
exactly what the assembler's own scratch map exists to say.

And SplitLint caught the second in code written an hour after the baseline
that catches it. In the blit set-up, RSTA writes a source address of zero
and then RSTA writes a bank number of zero - two unrelated quantities that
are equal by accident, in the most safety critical file in the repository.
It is marked with a reason rather than removed.
2026-08-26 23:31:04 -04:00
Anachronaut 612bd1b97c B1: a boot area on the disk, reserved by arithmetic that was already there
The first rung of booting from disk. A boot area is blocks between the
superblock and the directory that the filesystem never allocates and never
sees, and NOTHING WAS ADDED TO RESERVE THEM: both implementations work out
the first usable block as directoryStart + directoryBlocks, and
directoryStart has always been a field rather than a constant. Formatting
with the directory moved up reserves everything below it. Neither allocator
changed, on either side.

Two new superblock fields in bytes that were reserved: bootBlocks at 14,
per slot, and bootSlot at 16. A disk made before this has zero in both,
which reads as "no boot area" - true, and the same shape as the version two
parent field, where the value an older disk already held was the right
answer without conversion.

TWO SLOTS, ALWAYS. A boot slot is raw blocks with no entry to rename, so
the write-a-temporary-and-rename ordering that protects every file cannot
protect it, and a machine interrupted while updating its only slot would
not boot at all - the one failure on this disk with no way back. Writing
the slot that is not live and then moving one byte makes that a machine
that boots what it had before.

bootBlocks and directoryStart say the same thing from two sides, so a disk
where they disagree is refused rather than guessed at, as is one naming a
slot that does not exist.

Checked where it matters: the HOST formats a disk with a boot area and the
MACHINE fills it, then the reserved blocks are compared against zero. The
machine's allocator is the one that had no idea any of this was happening,
which is what makes that the check worth having. Six host checks besides,
including both halves of the superblock disagreeing.
2026-08-26 22:58:45 -04:00
Anachronaut 0a2965bc63 Name the rules, say when there is nothing to say, and hold a baseline
Four things SplitLint wanted, and they build on each other.

EVERY WARNING NAMES ITS RULE, in brackets at the end the way a compiler
names the flag that produced it. Twelve rules, listed by --help. That makes
the other three possible: suppressions can name one rule and leave the line
honest about the others, the harness can assert on a rule's identity rather
than on the wording of its message, and --machine can print one tab
separated line per warning - file, line, rule, message, help - so nothing
downstream reads prose. This file's own output was parsed with regular
expressions three times in one day before it had a shape to rely on.

A CLEAN RUN SAYS SO:

  No style warnings: 121 files checked against 12 rules.

It used to exit in silence, which does not tell you it found nothing - it
tells you nothing at all, and from outside the two are identical.

A MARKER THAT SILENCES NOTHING IS ITSELF REPORTED, as dead-suppression. An
exception that outlived whatever made it necessary is the thing the
required reason exists to prevent, and naming the wrong rule now gets you
both the warning you meant to silence and a note that your suppression is
doing nothing.

AND THE CORPUS IS HELD TO A BASELINE. Sixty one warnings are left in it
deliberately and nothing stopped a sixty second. Tests/lint-baseline.txt
records how many of each rule each file should produce, so a new one fails
make test while the sixty one stay quiet; confirmed by adding an INIA 0d0
to Say.asm and watching it name the file, the rule and the count. It counts
per file and rule rather than recording line numbers, because line numbers
would churn the whole baseline whenever anything was inserted above a
warning - the same reason cycle counts are stripped from recorded output
here. ./Tests/lint.sh --bless records it again.

One thing to know for next time: the rule name was inserted before the line
number at all twenty one call sites, and the signature was changed to match
rather than the twenty one call sites being fixed. (path, rule, line) reads
no worse than (path, line, rule) and one edit has fewer ways to go wrong
than twenty one.
2026-08-26 21:00:21 -04:00
Anachronaut 9c144469b4 Take the SplitLint findings that are one operation, leave the rest
Twenty four more sites, and the interesting part is which ones were left
alone. A rule emerged while reading them and it held all the way through:
apply where the repetition is INSIDE one operation, skip where the author's
own structure says it is a new thought, and never where two equal values
mean different things.

Taken:

- Five registers reassigned to a value they already held, where both are
  the same quantity: two masks in one expression in Snake, two spaces
  printed by the monitor, both halves of block zero in waitTest, and a RSTA
  in Pour that the very next instruction overwrote.
- Eighteen SETDs that reload a pointer inside one operation - a store back
  into the variable just read, or an INCD stepping to the second byte of a
  two byte value. Those read correctly without the reload.
- sbfsNext, which branched to the label on the line below it.

Left, with reasons that are the useful part of this:

- Eight registers where the same number means two different things. CosmOS
  and the loader set A to 1 for a blit command and then to 1 again for a
  bank number; Asm compares a type against 3 and then a status against 3.
  Removing those couples one quantity to another that is equal by accident
  and would part company silently.
- Ten RSTAs that open the RSTA/RSTB/CCF/ADD "return zero" block. The
  redundancy is what makes that idiom self contained; taking it out makes
  the return value depend on the line above.
- Eleven SETDs that begin an arm of a comparison chain. Each arm loads,
  compares and branches, and they get reordered - the repetition is the
  reason a new arm can be dropped in anywhere.
- Twenty five SETDs separated from their pointer by a blank line or a
  comment, which is the author saying a new thought starts here.
- Two CCFs before arithmetic, which this codebase writes unconditionally.
- Three redundant branches in test programs whose recorded output includes
  addresses, where three fewer bytes moves what the test demonstrates.

Nine recorded outputs moved and every one is a size in a listing or, for
Life, five more generations inside the same cycle budget. Behaviour is
unchanged everywhere: cosmosSnake and cosmosEdit pass byte for byte while
Snake loses eight bytes and Edit twelve.

CosmOS is 10,902 bytes of program against 10,937, and the native assembler
12,173 against 12,183. The CosmOS README's size for Edit moved twice in one
sitting, and this morning's check caught it both times - which it could not
have done before that claim was reworded to name what it was about.
2026-08-26 18:02:35 -04:00
Anachronaut e1273337c4 Two mechanical fixes SplitLint found: MVQA, and RSTA for zero
Twenty four places moved Q into A or B by pushing it and popping it back.
That is four bus cycles and two bytes to do what MVQA does in one of each,
and several of them are inside loops - Life, the calculator, int8. Nineteen
more loaded zero with INIA 0d0 where RSTA says the same thing in one byte.

Both are equivalent at the CPU rather than by assertion: RSTA and INIA both
leave Status alone, and PSHQ followed by POPA nets to A = Q with the Stack
Pointer where it started. The one difference is that the pair leaves a copy
of Q in memory just below the Stack Pointer and MVQA does not, which
nothing here reads.

Five recorded outputs moved and every one of them says the change worked:

- 16x16Life fits five more generations into the same cycle budget, the
  first 457 lines identical, because the loop got cheaper.
- Life.sbx is 1409 bytes rather than 1411, in three tests that list it.
- Edit.sbx is 1995 rather than 1996.

That last one broke a check I added this morning, and the hole is worth
recording: the CosmOS README's claim about Edit's size did not have the
word "Edit" on the same line as the number, because the subject was in the
sentence before, so the check that measures quoted sizes skipped it
silently. The sentence now names what it is talking about, which makes it
both checkable and clearer, and the check fails on a wrong number there.

Comments on either half of a replaced pair are carried onto the
instruction that replaces them, so nothing anybody wrote was lost.
2026-08-26 17:53:10 -04:00
Anachronaut c146d98588 Stop the linter recommending a change that a faster helper would break
SplitLint knew that CALL restores A, B and Data Pointers 0 to 2, so a
pointer set before a call is still set after it. That is true, and it made
the tool give advice that was correct today and unsafe to take.

Of the 178 redundant SETDs it found across the corpus, 122 were redundant
ONLY because of that restore - the shape is everywhere, because it is how a
helper is given its arguments:

  SETD.0 SbfsBlock
  SETD.2 SbfsFileStart
  CALL sbfsSetWord
  SETD.0 SbfsBlock        <- flagged

Removing that last line is right until sbfsSetWord is reached with RCAL,
which restores nothing - and that is not hypothetical, it is what RCAL was
added to this machine for, measured at close to halving the assembler's
memory traffic. The failure would also be silent from the linter's side: it
forgets everything across an RCAL, so it would stop reporting while the
removals stayed removed.

So a claim now ends at any call, for pointers and for registers, the way a
claim about carry already did. 257 warnings become 127, and the redundant
SETDs 178 become 54 - which is exactly the number an independent count of
"no CALL in between" had arrived at separately.

The fixture gained a SETD and an INIA repeated across a CALL, which must
stay quiet, and the harness fails with the old behaviour put back. Two
mistakes worth recording: the new expectations first pointed at the LABEL
above the repeats rather than the repeats, which passes for free because
nothing ever warns about a label; and the block landed in the middle of
another check's comment, leaving that comment describing the code below it
instead of its own.
2026-08-26 17:42:56 -04:00
Anachronaut 8f4cc5878d Repair a table cut in half, and measure the numbers that had drifted
The README's emulator options table was split by forty lines of prose: two
rows, then the whole discussion of the cost model, then five more rows with
no header above them. Markdown renders that second half as something other
than a table, so three of the seven options were not being shown as
options. The rows are back together and the prose follows them.

Four numbers had gone stale, in three different ways, and none was noticed:

- "Five more scripts run alongside it" - there are six, and lint.sh had no
  bullet saying what it was for.
- "rebuild all three tools" - there are four.
- Files.asm quoted at 645 bytes in two places; it is 665.
- Edit quoted at 1,983; it is 1,996.

The last two are the most quotable sentences in the CosmOS README and the
least likely to be rechecked by hand: the programs kept being made better
and the sentences about how small they are stayed where they were.

So docs.sh measures all four now. It counts the scripts in Tests/ that are
not the driver or the disk builder and checks the README says that many and
explains each one; it counts what the makefile's all target builds and
checks the tool count in both phrasings, which took two attempts because
one sentence says "the four tools" and the other "all four tools"; and it
assembles every app the CosmOS README quotes a size for and compares. Each
check was confirmed by making the fact wrong and watching it fail.

WAIT also added a second kind of cycle this morning and the cost model
section still described only one. It now says what an idle cycle is, why
the two are counted apart, and what that distinction is FOR - a machine
that slept through a slow disk and one that spun on it take the same
elapsed time and print the same characters, and only the split tells them
apart. The duplicated sentence about pipelining is gone; it was said twice,
eleven lines apart, in nearly the same words.
2026-08-26 17:32:22 -04:00
Anachronaut 2b079324ae Add SplitLint, and let it be told when something is deliberate
SplitLint reports valid assembly that has a shorter direct expression:
zero loads that could be RSTA or RSTB, Q moved through the stack where MVQA
would do, self-cancelling push and pop pairs, assignments overwritten
before use, unreachable fallthrough, one-byte pointer moves that could be
INCD or DECD, a branch to the label directly below it, a SETD reloading an
address the pointer already holds, and branches whose carry is known.

Its model is deliberately local and conservative: every label and every
directive forgets all known state, so a claim only ever lives inside a
straight-line region. It knows the calling convention - CALL forgets DP3
and keeps the rest, RCAL and SWI forget everything - and it shares
assembly.o with the assembler, so an added opcode cannot leave it holding a
private copy of the instruction table.

260 warnings across the corpus, of which three were wrong in the way that
matters: branchTest.asm and interruptFlagTest.asm exist to check that a
branch whose carry is known behaves correctly, so a diagnostic saying the
outcome is known is exactly right and exactly unwanted.

A line whose comment says "splitlint: <reason>" is now not reported on. THE
REASON IS REQUIRED and a bare marker is refused, because a suppression
nobody explained outlives whatever made it necessary. Suppressed warnings
are not counted, so --fatal-warnings does not fail on one, and the number
of them is printed at the end so the claim is visible rather than silent.

Tests/lint.sh checked a TOTAL: twenty three warnings expected, twenty three
found. That number stays right while the thing behind it goes wrong - a
rule that stopped firing while another fired twice would pass, and so would
a rule reporting at the wrong line. It now checks which warning came out
and at which line, that nothing else came out, and that the four lines
meant to stay quiet did. Confirmed by breaking one rule's message and
watching it name that rule: the old assertion passed the same sabotage,
because the warning still fired and the count never moved.

Written with the user while I was away; my part is the suppression
mechanism, the harness rewrite, and the three marks in the test programs.
2026-08-26 17:23:17 -04:00
Anachronaut c3188ed657 Seventy becomes seventy one: a machine that can wait
HALT is terminal - stepCPU returns at once when the Halt Flag is up, so a
halted machine does not execute, service devices, or take an interrupt -
and that has to stay true, because every test ends with a halt and "halted"
is how a program says it has finished. The consequence was that SplitBit
had no way to wait at all. Every wait was a spin, and a spin is bus
traffic: 11.5% of Type over a 14K file on a disk of ten thousand cycles,
after read-ahead had already hidden three quarters of the latency.

WAIT is 0xFE, one byte, no operands, sitting under HALT where the
instruction that almost stops the machine belongs. Three decisions in it:

- A line already standing means there is nothing to wait for, so WAIT does
  nothing. That is what makes test-then-wait race-free.
- Any line ends the wait, masked or not, so a program can sleep on a device
  it has no handler for and read its status afterwards. Masking says who
  answers a request, not whether it happened.
- A line that wakes the CPU without being dispatched is taken down by the
  WAIT. Left standing it would be found by the next WAIT, which would
  return at once - the program would spin exactly as before while looking
  as though it slept.

Waiting is NOT a Status bit, and that is the trap avoided rather than a
gap: Status rides into the interrupt frame and comes back out, so a machine
interrupted mid-wait would return from its handler still waiting, and wait
again for what it had already been given. An internal field instead.

Idle cycles are counted apart from bus cycles and the halt line says so
when there are any, which is what makes the difference observable at all -
with the line-clearing removed the total moves by ONE cycle, 20,100 against
20,099, and only the idle half changes, halving to 9,976. A test on
totals could never have seen it. Tests/terminal.sh asks that question,
being the file for things a recorded output cannot see, and fails with the
clear removed while "both reads finished" still passes.

Three collisions, all found by building it:

- 0xFE was the assembler's "not an instruction" sentinel. getOpcode now
  answers a negative NOT_AN_OPCODE, which is outside the range of every
  possible answer instead of inside the unused part of it.
- 0xFE was also what faultTest and faultResumeTest executed to provoke a
  fault. They now use 0xFD and say why, because they did not fail when it
  became an instruction - they HUNG, having started sleeping instead.
- Keys.asm has had a label called "wait" for a year, and mnemonics are
  matched uppercased. What that reported was "Branch without label" at the
  BRQ thirty lines away. The assembler now refuses a label that is already
  an instruction, at the label, by name; every instruction added takes a
  word out of the space of label names, so this will happen again.
2026-08-26 11:11:25 -04:00
Anachronaut 6b41354f8f Delete a comment describing a design that was removed, and check the rest
Two comments in the native assembler survived the changes that made them
false, and both are the kind that misleads rather than merely ages.

Asm.asm still explained an eighteen kilobyte buffer that the whole output
had to fit in "because a file is written in one call and there is nowhere
to put half of one" - which stopped being true when the assembler learned
to stream, and the variable it described, ImgRoom, does not exist any more.
It was sitting in front of the comment that replaced it, so the paragraph a
reader met first described the design that had been taken out. Replaced by
what is actually there: no limit but the disk, one block at a time through
a window in scratch.

scratch.asm said the system keeps below 0x1000 twelve lines above the
paragraph explaining that the system's half of Data Memory was doubled to
0x1FFF. A stale number next to its own correction is worse than a stale
number alone, because which one a reader believes is a coin toss.

docs.sh now checks both of the facts scratch.asm asserts about the machine
around it: the floor it claims the system keeps below, against the CosmOS
README, and the address its buffers start at, against where the assembler's
own data actually ends. Neither is enforced by a line of code anywhere -
the map is a comment, deliberately, because reserving the buffers would put
22K of zeroes in the file and the assembler could not load itself - so a
check is the only thing that can hold them. Both fail when broken; the
second reports the exact overlap.
2026-08-26 10:28:14 -04:00
Anachronaut ce0f18f4ef Refuse a directory whose last entries cannot be named as a parent
A parent is an entry index PLUS ONE in two bytes, so entry 65535 has no
parent number: adding one wraps to zero, and zero is the root. Eight
entries to a block, so 8192 directory blocks reaches it and SplitDisk
formatted that happily.

It does not fail by refusing, which is why it was worth chasing rather than
reasoning about. Reproduced on a disk built for it: mkdir /deep/child, with
/deep at entry 65535, printed 'Made "/deep/child" as entry 0' and put child
in the ROOT. Listing /deep then showed nothing, because the search is for a
parent of 65536 and the entry carries zero - so the same mkdir succeeded
again, and again, and five entries called /child piled up in the root.
Duplicate names in one directory are the one thing rename refuses outright,
on the grounds that a search answers with whichever it meets first and the
rest can never be reached; this manufactured them one per attempt.

8191 blocks is the most, giving 65528 entries. Refused when formatting and
again when reading, in both implementations, because a disk claiming more
was made by something that never checked. On the machine only the high byte
of the count has to be looked at: anything from 0x20 up is too many.

Three checks, all of which fail with their guard removed. The machine's
disk claims the size rather than having it, so the test image is 64 blocks
that lie rather than sixteen megabytes that do not - mounting is refused at
the geometry, which is read out of block 0.
2026-08-25 23:47:02 -04:00
Anachronaut 2b5506ee70 Stop the prompt writing off the front of its own buffer
The prompt is the working directory's path, worked out each time by walking
the chain of parents up to the root. The names arrive deepest first, so
they are written backwards from the end of a 127 byte buffer - and nothing
bounded that walk.

Nothing bounds the depth either. A path given to one operation is capped at
95 characters and a 22 character name, but "mkdir a" and "cd a" are each
far inside that and can be repeated forever. Six directories of 22
characters is 132 characters of path, and at that point the walk wrote down
past the front of CwdText and into what the assembler had laid out below
it: the shell's own command names. ExitName sits five bytes under, so the
word "exit" went first and the shell stopped recognising the command for
leaving. Measured, not deduced: fine at five levels, gone at six.

The walk now counts the room it has left, byte by byte, and stops. What is
already written is the DEEP end of the path, which is the end worth
showing, so it is cut at the front and three dots say so - out of three
bytes held back from the count, so there is always somewhere to put them.
Twenty levels deep the prompt shows the last five and every command still
works.

cosmosDeep records that, and records it by running help, cd and exit from
down there rather than by looking at the prompt: a wrong prompt is
cosmetic, and this was writing into other variables. It fails with the
bound removed. The tree is built by SplitDisk because a path that long
cannot be given to mkdir in one piece - which is the same fact that makes
the depth unbounded.

The three path limits are written down in the README now, including which
one actually binds. The other two do not: the longest path on a full
install is 21 characters.
2026-08-25 23:35:33 -04:00
Anachronaut ce8fb721fe Say a temporary is one in the entry, not in its name
Saving something that already exists writes a temporary, deletes the
original and gives the temporary its name, so that nothing is lost if the
writing fails. The temporary was told apart from a real file by being
called sbfs.part or sbfs.out - and those are legal names. Starting a save
deleted whatever answered to one as stale scratch, so saving anything at
all in a directory destroyed your own file of that name there, silently.

Flag bit 0x04 now says it. The property is not in the contents - the same
bytes become the finished file the instant the rename lands - so it belongs
in the entry, which is the thing the commit changes. sbfsCreateTempAt is
the door temporaries come in by, the commit writes the flags flat along
with the name, and cleanup wipes what it finds only if the entry says it is
ours. Anything else stops the save instead.

The bit is also the recovery. Both listings show an unfinished write rather
than sizing it, because the size in the entry is the room that was asked
for and not what was written: "<unfinished>" from dir, and a line from
SplitDisk saying the blocks are held and a rename brings the data back.
That was the gap in what the last commit documented - the data survived a
crash and nothing would show you where it was.

Four new agreement checks, three of which fail with the guards removed. The
fourth needed rebuilding first: both tests started on one disk, and the
first save ate the sbfs.part that was the second test's SOURCE, so the copy
failed for want of a file, never opened a stream, and passed while
reporting on nothing. A disk each. The fifth check forges the wreckage by
setting the flag on a finished file, since nothing here can crash a save
half way through.

No version bump: a committed file never carries the bit, so a disk this
writes is byte for byte the disk the old code wrote, which the whole-image
comparisons confirm. Only the wreckage differs, and older code reads that
as an ordinary file - which is what it did before.
2026-08-25 23:22:37 -04:00
Anachronaut aa7bdc6acd Check the memory map against itself, not only against the code
The CosmOS README's Data row gave the system 0x0000-0x3FFF and a loaded
application 0x2000 and above: two columns of one row that cannot both be
true. Program was doubled to 0x3FFF when CosmOS outgrew its first map and
that number was copied into the Data row as well, where the answer is
0x1FFF.

docs.sh measured both segments against the CosmOS column and passed the
table anyway, because it never read the column beside it. A number checked
against the code and not against the number next to it is still unchecked,
so it now reads both and compares them - and compares two further copies of
the same fact that had gone stale on their own: the minimal application in
the README, still based where applications lived before the doubling, and
the map cosmos.asm opens with, which somebody reading the system reads
before they read the README.

Each of the three checks was confirmed by breaking the fact and watching it
fail; the first reproduces exactly the text this commit removes. While in
that header, the command list said five commands and CosmOS has eleven and
a search path besides, and "dump is next" outlived the monitor.
2026-08-25 22:54:14 -04:00
AnachronautandClaude Opus 5 d4cba36c5e Devices that take time, and a filesystem that waits for one
The disk's status has always had a bit meaning "still going", and the header
beside it has always said to honour it. Nothing did, because nothing could: the
host finished the transfer inside the instruction that asked for it, so the bit
could never be seen up and asking about it was asking about something that
cannot happen.

--disk-cycles gives it a latency. The command is still checked at once, because
a refusal is not work - a block that is not there fails before any head moves -
but the transfer is remembered and done when the machine has run that far. Until
then the buffer holds the block BEFORE this one.

That last part is the point. A program that does not wait gets the wrong bytes
rather than an error, which is the failure the bit exists to prevent and the one
that would never have shown up. With a latency of two thousand, CosmOS could not
even mount: sbfsMount reads block zero and looks straight at the buffer.

deviceTick is the general shape rather than a disk feature. Called once per
instruction with the machine's clock, it lets anything whose moment has come
finish - which is what a display that refreshes, or a port that waits on the
host, would want in exactly the same way.

The filesystem watches the bit now, in one small routine reached with RCAL. That
is not decoration: what it hands back is the settled status in A, and CALL puts A
back the way it found it, so an ordinary call cannot carry the one thing this
exists to carry. Two bytes of Stack rather than ten, in a routine that runs on
every block the machine ever touches - the first place in the system where the
new call is the right one rather than merely a cheaper one.

The manifest takes a @N after a disk, the way it already takes :ro, so a test can
ask for a slow one. cosmosSlowDisk lists a directory at two thousand cycles a
block and gets the same listing as everything else, which is the whole assertion:
a filesystem that did not wait would print nonsense rather than fail.

Zero is the default and every other test runs at it. What waiting costs, on a
directory heavy run: 229k cycles at zero, 275k at five hundred, 415k at two
thousand, 1.16M at ten thousand.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 21:29:57 -04:00
AnachronautandClaude Opus 5 f1e5cc46f6 A cycle is an access to memory, not an instruction
cycleCount used to tick once per instruction, so RSTA cost what SETD cost and a
CALL moving ten bytes of Stack cost what a branch cost. No machine anybody could
build works that way, and the emulator's job is to be the thing the hardware is
designed against.

Every touch of memory now goes through one of four accessors that charge for it:
fetching an opcode, fetching the bytes after it, reading or writing Data Memory,
and reaching a device port. One access, one cycle, nothing overlapped. The
accessors exist so the cost is counted where the access happens rather than in a
table of per instruction costs kept somewhere else - a table like that is a
second copy of what the code does, and the two drift.

The run loop spends a budget of cycles instead of running a count of
instructions, so the emulated rate means something: an instruction costs what it
touches, and a batch ends when the cycles are gone.

What the numbers say now: RSTA 1 and SETD 4, being one byte and four. LDA 3,
DPUA 2. CALL and RET together 24, RCAL and RRET together 8, because the first
pair moves twenty bytes of Stack and the second moves four. The average SplitBit
instruction costs 3.72 of these, measured over the native assembler assembling a
program.

And the measurement that prompted all of this: converting the filesystem's
hottest leaf routine to RCAL is 3.1 per cent cheaper on a directory heavy
workload. The old model said 0.0, which is what a model that cannot see memory
traffic must say about a change that is nothing else.

Three tests moved. settle() strips the cycle count from recorded output, so
nothing should have churned - but it was anchored to the start of a line and
replCalculator's last output has no newline on it, which leaves the halt message
mid line where the pattern never reached. Not anchored any more.

The two Life programs are bounded by a cycle count because they never end, and
that number was rescaled from 3,000,000 to 11,200,000 - the same amount of work
at 3.72 cycles to the instruction. Nothing about either program changed. No limit
reproduces the old output exactly, because the cut now lands elsewhere in a
frame, so they are recorded again rather than tuned to match.

Whether hardware overlaps a fetch with the end of the previous instruction is
left open on purpose. This is the conservative model; pipelining is a decision to
make while drawing the hardware, not one to inherit from an emulator.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 20:44:38 -04:00
AnachronautandClaude Opus 5 54f5cfe8a4 Add Copy and Compare, which stream in both directions at once
Copy joins the read and write streaming services: source and destination are
both larger than Data Memory while the program owns one block. Compare reads
two files through separate blocks and ignores the bytes past a short final
block, which belong to neither file. Between them they exercise empty,
exact-block, part-block and 84,000 byte files, and the host extracts the copy
afterwards so that two native programs agreeing with each other is not the only
oracle.

Written by ChatGPT, as their headers record, along with the agree.sh section
and the manifest entry that drive them.

THIS SHOULD HAVE COME FIRST. The commit before it staged whole files rather
than the hunks it meant, so its manifest already names these two programs while
their source was still untracked - that commit will not build on its own. Left
in place rather than rewritten, since the pair is right and only their order is
wrong.

NOTES.md is their review of the streaming work. The first item in it is fixed
by the commit before this one; the rest are still open.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 20:21:43 -04:00
AnachronautandClaude Opus 5 a7d3e09d94 Refuse a streamed file that commits more than it reserved
osFileStart sets an extent aside and osFileWrite refuses a block index outside
it, so writing off the end was already barred. Committing a larger size was
not, and reaches the same neighbour by simply claiming it: a directory entry is
the only record of what a file owns, so an entry claiming a block it was never
given owns it, and so does whatever owned it before. Both files then look
perfectly well formed. The free count went backwards past zero on the same
path.

Found by ChatGPT's review of the streaming work, in NOTES.md. I had bounded the
index because writing off the end was the obvious way to reach a neighbour, and
had not noticed that the other end of the same reservation was open.

THE SIZE IS COMPARED, NOT THE ROOM IT TAKES UP. One block and a tail occupies
exactly what two whole blocks occupy, so bounding the blocks alone would let a
file reserve the first, commit the second, claim no block it was not given, and
still report two hundred and forty six bytes that were never written to it -
whatever the disk had there before.

Checked before anything is touched, which is why the temporary is found twice.
The old file is deleted a few lines down and a refusal after that point would
have destroyed the thing it was protecting.

AND IT CAUGHT A REAL ONE IMMEDIATELY. The assembler reserves the file plus room
for its vectors, and asked for four bytes per vector DECLARED - which looks like
a safe bound and is not, because a device is declared during the SECOND pass, in
the line that implements it. A program with a device installs a vector that was
not counted when the room was measured. CosmOS reserved 14,163 bytes and
committed 14,167, writing four bytes past what it had been given on every build
since S2. It landed inside the last block it owned, and would not have if the
boundary had fallen four bytes earlier.

It reserves against the vector table's LIMIT now, which cannot go stale whenever
things are counted.

Claim.asm is the program that tries it: reserve one block and a tail of ten,
write them, then tell osFileDone the file came to two whole blocks. The refusal
and the honest commit that follows are both recorded.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 20:20:39 -04:00
AnachronautandClaude Opus 5 af0360128b Sixty four instructions becomes seventy
The six settled back on the twenty fourth, built now.

RCAL and RRET are a call that puts nothing back. CALL restores A, B and Data
Pointers 0 through 2, which costs ten bytes of Stack and is why a subroutine
here can only hand anything back through Q, DP3 or memory. RCAL costs two and
restores nothing, which is what a short leaf routine wants and is unsafe in
exactly the way the name says.

They are a pair because the frames are different sizes: returning from one
through the other walks the Stack to somewhere that was never a return address.
That was the user's correction to the original proposal, which had a raw call
and no raw return.

DPUA and DPDA offset a Data Pointer by A; DPUW and DPDW by A and B together,
most significant first. DPUP and DPDN take a byte written into the program, so
moving a pointer by something just worked out meant storing it and loading it
back. Down as well as up on symmetry grounds, which was also the user's call -
the argument against it came from counting uses in a corpus written under the
constraint.

The opcodes sit where they belong: 0x16 and 0x1E immediately below CALL and RET,
and 0x4E through 0x51 at the end of the Data Pointer family. All six fit shapes
that already existed, so instructiontable.py needed only set membership and both
machine side copies of the table regenerated from it unchanged.

Checked at every level it exists at: the emulator runs them, the host assembler
encodes them, the monitor disassembles all six with the right lengths, and the
assembler that runs on the machine builds a program using them byte for byte
identically to the host - and that program runs.

The recorded test measures what the two calls COST as well as what they put
back, because an RCAL that quietly did what CALL does would still return to the
right place. It does not survive that: returned through RRET, it hangs.

docs.sh can read a two word number now. The count of instructions taking a Data
Pointer went past twenty, and the pattern only allowed one word, so the check
would have reported that the manual had stopped saying it rather than that the
number was wrong.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 17:29:43 -04:00
AnachronautandClaude Opus 5 00d896e3e7 Break shows registers it chose, not ones it inherited
Break left DP1 and DP2 alone, so what a stop printed for them was whatever the
shell happened to have left there - which is a CosmOS address, which moves
whenever CosmOS is touched at all. The recorded output had to be taken again
four times in one day's work, every time for a value that is not this program's
and that nothing should ever depend on.

It sets all three of the pointers it owns now, rotated between the two stops so
that every one of them visibly changes, the way A and B already did. DP3 stays
as the system left it: it is where the program was entered, which is the one
thing worth seeing here that this program did not choose, and it is steady
because it is this program's own base.

A demonstration of what the registers were should show registers somebody
chose. Then every line of the record is being asserted rather than merely
observed, and a reader can tell which is which.

Checked both ways: sixty four bytes added to CosmOS's data no longer moves it,
and reading the frame at the wrong offset still fails it.

cosmosRun and cosmosMonitor move because Break is sixteen bytes longer and both
of them list the disk it sits on.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 17:13:49 -04:00
AnachronautandClaude Opus 5 fb7b224bbb S2: the assembler writes the file as it makes it
The output image is gone. It was eighteen kilobytes and it is now one block of
window, because the file was always produced in order and only ever needed to
be written that way.

Everything works in FILE OFFSETS now. A cursor is a two byte number counting
from the front of the file, and since a block is two hundred and fifty six
bytes, the block it lands in is the offset's high byte and the place within that
block is its low one - so there is no division anywhere, and ImgWalk, ProgPut
and DataPut needed no change but where they start.

ONE WINDOW RATHER THAN THREE. The plan said three: one per segment, and a third
for the block where the program ends and the data begins, which belongs to both.
Fetching a block back instead makes all of that one case. The header is patched
after every byte is out, the boundary block is written by both cursors, and both
are simply revisits - a revisit is what fetching handles. osFileFetch is the
service that allows it, and is the read side of the write.

A run of bytes in one segment costs nothing extra; a switch between segments
costs two block operations, and a source file has a few dozen switches and
several thousand bytes.

Two bugs, both a pointer meaning two things:

putAt took the cursor to advance in DP2 and then wanted DP2 for the window's
address. A call puts DP2 back the way it was AT THE CALL, so the step at the end
moved whatever the last call had left there - the window walked off across
memory while the cursor stood still. It goes in memory now, like the block did
in S1, and for the same reason.

The size the file is created at could not be right. How many vectors are
actually installed is not known until the second pass has resolved their
handlers, and by then the file must already exist to be written into - so Keys,
which brings one vector, came out four bytes short. Teaching the first pass to
count them meant teaching it about devices, and about a Boot line in a loadable
program not being installed at all, which is two ways to disagree with the
second pass about what a file contains.

So osFileDone is told the size instead. A writer asks for as much as the file
could possibly come to - the whole of it plus four bytes for every vector
DECLARED, which no file can exceed - and says what it really came to at the end.
The blocks it did not use go back to the free count. Asking for too much costs a
moment; asking for too little writes off the end of a file.

That is a better service for it, not a workaround. A writer that cannot know its
size until the last byte is the ordinary case, and it is exactly the case this
whole rung exists for.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 16:58:17 -04:00
AnachronautandClaude Opus 5 9f7dffdeca S1: the write side learns to stream
osFileStart, osFileWrite and osFileDone are the mirror of osFileInfo and
osFileBlock. A program can now write a file it never holds: Pour writes twelve
blocks and a tail while keeping 256 bytes of it at a time, and the host tool
reads all 3,112 bytes back with every block where it was put.

ONE WRITE IS OPEN AT A TIME AND COSMOS HOLDS IT. Reading needs no state - a name
and an index are the whole question - but writing safely does, because the new
file has to exist before the old one is thrown away and something has to
remember which temporary belongs to which name. Keeping that here means the
careful order is written once instead of in every program that streams.

Nothing already on the disk is touched until osFileDone, so a disk without room
says so while the old file is still there. That is stronger than osFileSave can
manage, where the size is only known once the caller has every byte in hand.
osFileSave stays: Edit and Files hand over whole documents and have no reason to
learn any of this.

osFileWrite refuses an index past the end of the file, and that refusal is not
politeness. Files are contiguous, so block nine of a three block file is a real
block belonging to something else, and writing it would put one file's bytes
inside another with nothing anywhere saying so. Checked both ways: the tail
block is allowed and the one past it is not.

Three bugs, all of them the same shape - a register or pointer used for two
things at once:

DP3 carried the block count in and was popped high byte first, which is the
wrong way round from every reader in the system and made the count two hundred
and fifty six times too big.

sbfsStreamStart took the name in DP0 and then wanted DP0 for something else
before it had read it, so it walked whatever it last pointed at and reported
that it could find no room.

sbfsStreamWrite kept the caller's block in DP3 across a find - DP3 being the
pointer a return does not put back, which is exactly why the find uses it too.
What went to the disk was whatever the scan last looked at. It goes in memory
now, and the file is correct because every block says which block it is; a
check on the length alone would have passed all three of these.

Writing no longer finds the file for each block either. Nothing moves a file
once it is made, so where it starts is settled when the temporary is created.
That was not even slow - a scan stops the moment it matches - but it was a walk
of the directory per block for an answer that cannot change, and it is 28 per
cent of the cost of writing forty blocks.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 14:53:37 -04:00
AnachronautandClaude Opus 5 06bdbf7728 D5: move in, and give the assembler somewhere to look
The demo disk is three directories instead of thirty nine names in one list
with cosmos.asm sitting between fileStream.asm and sbfs.asm:

  /Apps    what you run
  /Source  what you name to the assembler
  /Lib     what those include

The split is by ROLE rather than by which directory the host keeps a file in.
Everything in /Lib is named by an #Include somewhere and by nothing else, which
is what makes it a library rather than a source.

THAT LAYOUT WAS NOT POSSIBLE UNTIL NOW, and finding out why is what this rung
actually cost. An include on the machine was a bare name resolved where you
stood, so every source that calls a service had to sit in the same directory as
services.asm - which is every source worth having. The first arrangement of
this disk put the examples in a directory of their own and none of them would
assemble.

So the native assembler has a search path: beside you, then /Lib. The same rule
the shell already uses for a program it does not recognise, applied to the
thing that reads source, and the same reasoning for it being two fixed places
rather than a list - a list needs somewhere to live between one boot and the
next, and there is no such place yet. It also brings the native assembler
nearer the host one, which has searched -I directories since before there was a
machine to run this on.

The reader's per-file state grew from 293 bytes to 301, because the name it
keeps is a path now and every block of a file is asked for by it. Six of those
would no longer fit the room set aside, so the include list moved up a page.
Both numbers are written down in two places on purpose and both were changed.

dir said cosmos.asm was 17,460 bytes. It is 82,996. The size came out of the
block count's LOW BYTE shifted up and the tail beneath it, which is sixteen
bits, so anything from 256 blocks upward came back as itself less 65,536 - a
plausible number, and wrong. Files that big say their size in blocks now.
Printing the true figure wants decimal printing twenty four bits wide, which is
a page of console.asm to say something nobody reads more precisely than "big".

The Assembler Manual's line about SBFS being flat was the last thing in the
repository still claiming it, and docs.sh now looks for that phrase and three
like it in all four documents. Not a section that is wrong - one clause inside
a paragraph that is otherwise right, which is the shape this kind of staleness
takes.

The duplicate puts are gone with the wildcard that caused them, so building the
disk is quiet.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 10:04:12 -04:00
AnachronautandClaude Opus 5 da91a36d92 D4: the machine makes directories too
mkdir and rmdir are the machine's own now, and a file goes where its path says
rather than always in the root. A disk can be organised without the host tool
touching it.

Everything below the surface works in terms of a directory and a name rather
than a path. sbfsWalkParent splits the last name off, walks the rest, and hands
back the two - and the separator stays on the end of the head, which is what
makes one rule cover every kind of path: "/x" leaves "/", which is the root;
"x" leaves nothing, which is where the machine already is; and "A/x" leaves
"A/", which is neither and needs no special case to say so.

Saving works in those two as well, and had to. The careful order a save uses -
make a temporary, write it, delete the original, rename the temporary - only
works if the temporary is made in the SAME directory as the file, because the
rename at the end changes a name and does not move anything. Renaming to a path
naming a different directory is refused for that reason, rather than quietly
being a lie the disk goes along with.

Three things this cost, all found by running it:

mkdir Apps/Deep made /Apps/Apps. The leaf was worked out into SbfsWanted and
then the head was walked - and walking goes through sbfsPathNext, which puts
every name it meets into SbfsWanted on the way past. The head's last name
landed exactly where the leaf was. It has somewhere of its own now.

rmdir took a directory with something still in it, which is the one failure the
whole design is arranged to prevent. Looking for children clobbered DP2 and
rebuilt it from the buffer and the entry count with the subtraction the wrong
way round, so the pointer walked off the end of the block and found nothing.
The comparison goes through a CALL now, like the two beside it, and DP2 comes
back on the entry because a RET puts it there. SplitDisk's "in use but not
reachable from the root" line is what caught it.

Refusing a name longer than twenty two used to read the twenty third character
of a shorter one, which is somebody else's string. It is measured now.

Tests/agree.sh is new and is the gate this rung was for: the same disk built
twice, once with SplitDisk and once with CosmOS, compared byte for byte. The
two share no code and only a written specification, and every field one writes
and the other only reads is checked there and nowhere else - which entry a
thing lands in, which block, what a directory's unused fields hold, the
version, the free count. It caught a wrong parent immediately when that was
broken on purpose.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-25 09:18:29 -04:00
AnachronautandClaude Opus 5 36ce9f6ccf D3: the machine knows where it is
cd moves it, dir lists the directory it is in, and the prompt says which one -
but only when that is not the root, so a machine nobody has moved about on
looks exactly as it always did and every recorded test that never says "cd"
keeps its recorded prompt.

A path beginning with a separator is measured from the root and anything else
from where the machine is, so a bare name means a file in the current
directory. NO PROGRAM HAD TO BE TOLD: the working directory lives in sbfs.asm
beside the thing that resolves paths, because it is what a relative path MEANS.
Keeping it in the shell would have meant either handing it down on every call
or pasting it onto the front of every name, and the second of those is how a
name that is already absolute gets ruined.

Nothing stores the path. The working directory is an entry index and two bytes,
and the text on the prompt is built each time by walking the chain of parents
upward, writing names from the end of a buffer towards the front - which is the
order they arrive in, and saves reversing them afterwards.

sbfsFind splits into a walk and a check. "cd /" and "cd .." both end at the
root quite legitimately, and had no way to say so through a routine whose only
word for the root was "missing".

Typing a program's name now tries two places in order: where you are, then
/Apps. The first makes a program you are working on the one that runs; the
second lets Snake work from anywhere. A word already beginning with a separator
has said where to look, so only that place is tried.

osChangeDir exists so that "a program may move about, and the shell puts the
working directory back" is a thing that can happen rather than a promise about
nothing. Both halves of that were unfalsifiable without it: with no way for a
program to move, removing the restore changed no test. Wander is the program
that moves - it goes where it is told and reads a file there by a bare name -
and with it on the disk, removing the restore fails.

The remembered file is dropped whenever what a relative path means changes: a
cd, a program calling osChangeDir, a program exiting. Removing all of them
fails the test and removing any one of them does not, because today every path
into that cache belongs to a program that exits. It is kept in all three
because the cost is a call and the failure is a file's blocks being handed out
under another file's name.

The cwd fixture holds two files called notes.txt saying different things, and a
Say.sbx in /A that is really hello. Two copies of one program, or two copies of
one file, would have passed with the whole of this deleted.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-24 22:22:45 -04:00
AnachronautandClaude Opus 5 588e02aff5 Double CosmOS's half of the machine, and check that it fits
The memory map gave CosmOS 0x0000 through 0x1FFF of Program Memory and
applications 0x2000 and above. CosmOS is 8141 bytes at the previous commit,
which is fifty one bytes short of the line, and the next thing added to it
went over.

GOING OVER DOES NOT FAIL WHERE IT HAPPENS. Nothing enforces the division: an
application says where it goes with #Base and the loader puts it there, so a
CosmOS that has grown past 0x1FFF simply has the next program loaded written
over the end of it. What breaks is whichever part of the shell that program
happened to cover, at whatever later moment somebody uses it. It turned up here
as the monitor's assemble command answering "I do not know" to valid
instructions, several commands into a session, on a machine that had booted
perfectly well.

Both halves are doubled: applications now start at 0x4000 in Program Memory and
0x2000 in Data Memory. That is 16K of code and 8K of data for the system,
against the 8775 and 2948 it uses today. Both were on the same trajectory, and
moving them together means the twenty files that say #Base are edited once
rather than twice.

The standalone loader's loadable.asm keeps its old base: it belongs to the
loader CosmOS grew out of, not to CosmOS, and its addresses answer to a
different program. The unbased-segment diagnostic keeps its old base too - it
exists to produce an error message that names the address, and the message is
what is recorded.

Tests/docs.sh now reads the two limits out of the table in the README and
measures both segments against them. It reads them rather than being told them
because the table is the specification, and this is the second time in this
project that the thing nobody checked is the thing that rotted.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-24 22:21:02 -04:00
AnachronautandClaude Opus 5 36a1b07b5b D2: the machine walks a path
sbfsFind takes a path where it used to take a name: names with '/' between
them, walked from the root, with '.' and '..'. Each name is looked for among
the entries whose parent is where the walk has got to. A bare name is a path of
one name, so everything written before directories existed still works and
still costs one walk of the directory.

sbfsMount takes either version. On a version one disk every entry has zeroes
where a parent goes and the walk starts at zero, so the comparison always
agrees - which is how a flat disk reads correctly here with nothing done to it.

PROGRAMS DID NOT HAVE TO BE TAUGHT ANY OF THIS. Resolution sits inside
sbfsFind, below the services, so every osFile call keeps its signature and a
path is simply a longer name. Type, More, Edit and the assembler gained
subdirectories without a line changing in any of them.

Four things this turned up, none of which was the path walk:

load copied the path into a buffer sized for a NAME, so anything over 22
characters was cut short - and cut short into a path that often still resolved.
"/Apps/Deep/../../Apps/Say.sbx" became "/Apps/Deep/../../Apps/" and reported
that the program was a directory. That is the whole of what looked like a bug
in '..', and it cost most of the time here.

load on a directory SUCCEEDED. A directory has no blocks, so reading it reads
nothing and leaves the staging area holding whatever was staged last - which,
if that was a program, still says SBEX and still has a working entry address.
It handed back the program before it. Refused outright now.

delete and rename on a directory are refused, and save refuses one up front
rather than failing at the rename and leaving a temporary behind. Deleting a
directory frees an entry index, and a parent IS an index, so the next file
created would take it and inherit the children.

create writes the parent rather than leaving it zero by luck. It would be zero
- delete wipes all thirty two bytes and a fresh entry never had any - but that
is a fact about two other routines, and a file appearing inside a directory it
was never put in is not a failure anybody would think to look for.

dir marks directories and counts them apart from files, because at this point
it was calling them files of no bytes.

Two hazards written down in the design note turned out not to be real, and both
were checked rather than argued about:

The lookup cache holding 22 bytes of a longer path cannot hand back the wrong
file - textSame wants both strings to end in the same place, so a cut down
entry misses. It can never HIT either, though, so every path longer than a name
went to the disk every time; it holds a whole path now.

The allocator stepping over directories changes nothing any test can see. A
directory has no start as well as no blocks, so its bounds are nought to nought
and no candidate begins before it ends. The four instructions stay, with a
comment saying they are not load bearing today and why they are there anyway.

makedisks.sh resolves its build path before it cds. Given a relative one it
carried on and quietly built disks missing some of their files, which is how
the tree fixture lost a file and sent me looking for a bug in '..'.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-24 19:08:26 -04:00
AnachronautandClaude Opus 5 78e9eef472 D1: teach SplitDisk directories, without moving a byte
SBFS version two adds directories out of space each entry had already set
aside: two of the four reserved bytes become a parent, and one of the seven
spare flag bits says an entry is a directory. The entry is still thirty two
bytes, so it still divides two hundred and fifty six and still never straddles
a block, and nothing in the block layer knows anything happened.

A directory is an entry with no blocks. That is what keeps the flat array of
entries the whole allocation map, which is the property the format is built
on: with files laid down contiguously, every block is inside some entry's
range or it is not, and an entry with no range is in nobody's way. There is
still no allocation table to consult and none to keep right.

THE PARENT IS AN INDEX PLUS ONE, so zero means the root. A version one disk has
zeroes in those bytes, and "in the root" is exactly where every file on a flat
disk is - so a version one image is already a valid version two image, with
nothing to convert and no tool to convert it with.

A disk is at the lowest version that describes what is on it. format makes a
version one disk and mkdir is what raises it, so everything built here stays
readable by a reader that has never heard of a directory right up until it
really does have one. That is what lets this land before the machine knows
anything: the whole existing suite passes untouched.

The tool gains mkdir and rmdir, and list, put, get and delete take paths. list
also now reports entries used against entries available, because a disk has two
ceilings and the entry one is the one nobody notices until it bites.

rmdir refuses a directory with anything in it, and that is not politeness:
parents are entry indices, a freed index gets handed out again, and the
children of a removed directory would reappear inside whatever took its place.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-24 18:41:11 -04:00
AnachronautandClaude Opus 5 2b0aeeefd4 Start a program by typing its name
A word the shell has no command for is now looked for on the disk as
"<name>.sbx", and if it is there it is loaded and started exactly as load and
run would do it. Whatever followed the word reaches the program through
osArgument by the same route as whatever follows run, so "Say hello there"
and "Type notes.txt" work without either program knowing how it was started.

load and run are unchanged and both stay. load is how the monitor puts an
arbitrary file in front of itself, which typing a name deliberately cannot do:
the extension is added rather than assumed, so "notes.txt" looks for
notes.txt.sbx and a text file is unreachable by name whatever is inside it.

Three things this had to get right:

The built-ins are tried first and always win. The search hangs off the end of
the dispatch chain, so a file called dir.sbx cannot become dir, and the
commands worth trusting when the disk is what you are doubting stay
trustworthy. The invoke disk carries a working dir.sbx so that this is checked
rather than asserted.

A file that is found but is broken says so. "not a program" and "I do not
know" are different answers, and giving the second about a file sitting on the
disk would send somebody looking in the wrong place. loadProgram therefore
hands back a status as well as a message, since only "no file of that name"
can fairly be reported as anything other than a fault.

doLoad became that subroutine rather than being copied. It ends in RET instead
of a jump to the prompt, and each way of failing sets its number and its text
together so a new one cannot leave half of the answer behind.

cosmosBreak moves because Break prints the pointers it was handed and those
are the shell's leftovers, which a CALL now puts back.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-24 17:25:50 -04:00
AnachronautandClaude Opus 5 dbe58db660 Add Type and More, and the file stream they are built on
Two applications that read a file too big for Data Memory: Type prints one,
More pages it. Both sit on fileStream.asm, which wraps osFileInfo and
osFileBlock into open-and-next so an application walks a file's blocks without
repeating the service calls.

The disk fixture is deliberately awkward: readable.txt crosses several blocks
and carries no zero byte to be mistaken for an end marker, and empty.txt says
that zero blocks is a valid file rather than an error.

These three files were written by ChatGPT, as their headers record.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-24 17:15:53 -04:00
AnachronautandClaude Opus 5 4e5710a1e6 Make the README's references clickable, and check that they land
The two manuals and the CosmOS README were named in prose and nothing else,
so reading about them and getting to them were separate acts. They are links
now, along with every directory in the repository map, which is the other
place somebody reading that page wants to click.

THE MANUALS HAVE SPACES IN THEIR NAMES, so the links carry %20. That detail
is why this is checked rather than eyeballed: a link with a raw space in it
points at a file that exists, so nothing about the filesystem is wrong -
the renderer just stops at the space and the link goes nowhere useful.

Tests/docs.sh now walks every relative link in every tracked markdown file
and complains about both failures: a target that is not there, and a target
with a space that should have been encoded.

Both verified by breaking them. The first attempt at that verification was
itself wrong - I removed the %20 and the check passed, because the file
really does exist under that name. That is what showed the two failures are
different things and both need catching.

13 links, all landing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-21 16:29:21 -04:00
AnachronautandClaude Opus 5 306b4dce92 Give the Programming Manual a title, and send the boot image format away
Last of the four. What was left after the reorder was a document whose first
heading was "General Description" doing a part title's job without being
one, and a section called "Input and Output In the Emulator" that held two
console ports, a worked program, and a file format.

  A title and an opening that says what this document is FOR, and what the
  other two are for, so a reader who wants the operating system or the
  language knows immediately they are in the wrong file.

  "General Description" is "The Machine", which matches the three part
  headings the reorder gave the rest.

  "Input and Output In the Emulator" is "Making It Print Something", which
  is what the section is: port 0, and the shortest program that uses it.

THE BOOT IMAGE FORMAT MOVES TO THE ASSEMBLER MANUAL, beside the loadable
program format, for the reason SBEX went there: it is a thing the assembler
WRITES. It is fair that the emulator reads them too - both tools speak it,
the way SplitDisk and sbfs.asm both speak the filesystem - but only one of
them makes one.

And it is called a boot image now, in the text as well as the heading. That
is what this project has been calling these files for a while; the manual
was still saying "binary", which now means either kind of output file and so
means neither.

A CHECK THAT GOT BETTER BY BEING SPLIT. The hello world program and the hex
dump of it were both in the Programming Manual, and docs.sh compared them
with each other and with the assembler. The program stays with the machine,
where the reorder put it just after the instruction list; the dump goes with
the format it demonstrates. So the check now settles THREE things against
each other: what one manual prints, what the other prints, and what the
assembler actually makes. Verified both ways - a wrong byte in the dump, and
the anchor renamed.

The manual is 692 lines and four parts. It was 1,116 lines and nineteen flat
sections when this started.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-21 14:44:11 -04:00
AnachronautandClaude Opus 5 fa3982dbd9 Move the CosmOS third of the Programming Manual to CosmOS
386 of the manual's 1,116 lines documented an operating system rather than
a machine. The split inside that file was never tutorial against reference;
it was the machine against the software that happens to run on it.

  What A Program May Ask The System For   129  -> CosmOS README
  Programs That Come With The System       111  -> CosmOS README
  Reading And Writing The Filesystem        64  -> CosmOS README
  Loading A Program From A Disk             52  -> Assembler Manual
  The Console Library                       25  -> CosmOS README

The services are the clearest case: a hundred and thirty lines describing
what CosmOS offers a program, in the manual for a CPU that has no operating
system of its own. A different system on the same machine would offer
different services and that section would be wrong for it.

The loadable program format goes to the Assembler Manual instead, because
SBEX is a thing the assembler WRITES. Nothing in the CPU knows what it is.

The Programming Manual is 716 lines and fourteen sections now, all of them
about the machine.

TWO DUPLICATE DESCRIPTIONS COLLAPSED INTO ONE EACH. The application list
existed in both documents in different words, and the CosmOS copy had gone
stale - no Break, no Stream, no assembler - because only the manual's copy
was checked. Moving the checked one in and deleting the other leaves one
list, and docs.sh follows it.

The second was made by this commit and caught while reading the seams: the
CosmOS README already had a service table, so the move briefly produced two.
That section now says what services are for and points at the one table.

Renaming a section as it moved: "Reading And Writing The Filesystem" is
"The Filesystem Library", which says what it is and reads beside "The
Console Library".

docs.sh follows all five, and each was verified by renaming the heading in
its new home and reading the complaint. The README and the CosmOS README
both described what the other manuals cover, and both were wrong the moment
this landed; they say the division out loud now, since it is the point.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-21 14:35:18 -04:00
AnachronautandClaude Opus 5 460a687939 Make the manuals plain ASCII, and check that they stay that way
"All files must be plain ASCII, the user's tooling doesn't support Unicode"
is a standing rule of this repository. Nothing enforced it, so it drifted:
39 em dashes and an ellipsis had collected in the two manuals, every one of
them typed by something that helpfully substituted a nicer character. The
spaced em dash becomes a spaced hyphen, which is what the source comments
and both READMEs use for the same job.

Tests/docs.sh now checks every tracked file and says which line and which
character. Verified that it bites.

THE CHECK READS git ls-files NUL SEPARATED, and that is the whole reason
this went unnoticed. I ran the obvious shell version of this audit two
commits ago - a loop over $(git ls-files) - and reported the repository
clean. It splits on whitespace, so it looked for a file called "SplitBit",
failed into /dev/null, and found nothing wrong with either manual because it
never opened them. Both have spaces in their names.

A check that cannot see the files with spaces in their names is worse than
no check at all, because it answers.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-21 14:16:54 -04:00
AnachronautandClaude Opus 5 b2945e41c4 docs.sh: say which heading went missing, rather than raising IndexError
The manual checks find what they examine by splitting the file on an exact
heading. Ten of the eleven anchors already say what they could not find -
"the Programming Manual has lost its Devices table" and so on. Two did not:
the worked hello world program and the hex dump beside it were reached with
pm.split(anchor)[1] and nothing else, so renaming either produced a Python
traceback and an IndexError.

A traceback is a worse answer than a stale manual. It says a check broke
without saying which heading moved, and it stops the rest of the run, so
whatever else was wrong stays unreported.

Both anchors are now tested before they are used, and both say which one is
missing and what that means. Verified by renaming each and reading the
message.

This is the first of four commits restructuring the Programming Manual, and
it comes first on purpose: the next three move headings around, and they
should be watched by checks that would notice.

IT ALSO CORRECTS THE PLAN. I had written that renaming a heading fails
silently, and set out to fix all eleven. Probing them one at a time showed
that was wrong - ten were already fine, and the job was one check rather
than the whole file. The claim was worth testing before acting on it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-21 14:11:37 -04:00
AnachronautandClaude Opus 5 ccf4b384e1 Give Programs/ one rule: a directory per kind, nothing loose
Five .asm files sat at the top of Programs/ beside six directories, with
nothing to say which a new file should join - and hello.asm, which is the
native assembler's first target and named in sixteen places, looked like a
stray.

    Programs/
      Examples/     what you read to learn: hello, printHello, inputTest,
                    replCalculator, and Fibonacci, primeSieve and gameOfLife
                    as sets of their own
      Libraries/    included by name, no entry point of their own
      Loader/       loader.asm, and the loadable program it reads
      CosmOS/       the system, its applications and its assembler
      testPrograms/ what 'make test' drives

Loader/ is the one worth explaining. loader.asm is not a demonstration: it
reads a program off a disk, puts the two pieces where the header asks, and
jumps to the entry. CosmOS grew out of it and does the same thing as one of
its commands. It is kept because backward compatibility with the simplest
version of the system is a standing goal, and it was sitting loose next to
the demos as though it were one.

Programs/loadable/ was a directory holding one file called hello.asm - a
third thing of that name, and the name said nothing about why it was there.
It is Loader/loadable.asm now, beside the loader that reads it.

Every reference moved with them: the makefile's program list, twelve
manifest lines, makedisks.sh, native.sh, and four paths across the README
and both manuals. Verified by deleting both build directories and running
the whole suite from nothing.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW
2026-08-21 13:38:47 -04:00