Written by Anachronaut and not previously committed. Three things in it had
gone stale between writing and now, and are corrected here rather than
committed knowingly wrong:
- the shell command table still described dump, which the monitor
supersedes, so it now describes monitor mode and its commands
- the service table listed four services, and there are nine
- the application list did not mention Files
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The editor included sbfs.asm and console.asm, which was 3235 of its 4941
bytes. Both come out: reading and writing a file, printing and reading a
line are services now, and sbfsMount goes entirely because the system has
already mounted the disk. Only text.asm remains, at 357 bytes, because
textSame and textNumber own nothing and touch no device - sharing those is
a linker's job rather than an operating system's.
4941 bytes to 1983, a little better than predicted because dropping the
mount and the blocks-and-tail arithmetic went with the library rather than
being translated.
ConsoleEndOfInput went with console.asm, so the end of input is now read
from the console status port. That is better than what it replaced: the
port is there whether or not the system is.
Nothing it does changed, and that is checked rather than asserted. The
recorded output of the cosmosEdit test does not move by a single byte
across this commit - a test written days before the rewrite, checking a
property rather than an output, and therefore able to verify a change it
knew nothing about.
One thing is lost and worth naming: there is no way to ask whether a disk
is present, so the editor's "there is no disk" message is gone. On a
diskless machine it now opens an empty document and fails at w instead. The
shell already refuses to load without a disk, so the editor cannot normally
be reached that way.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Two changes that arrived together because both live in cosmos.asm.
THE SERVICES. A loaded program that wanted a file had to include the whole
filesystem, carrying two and a half kilobytes of a private copy of code the
system already had running, and then mount a disk that was already mounted.
Five services are added at pinned numbers 20 to 24: osFileRead, osFileSave,
osFileDelete, osFileRename and osPrintNumber.
The sizes fit the registers exactly in both directions. A file that can be
read into Data Memory is under 64K by definition, so its length is sixteen
bits: coming back it is DP3, going out it is A and B together, and neither
direction needs a record in memory whose shape both sides must agree on.
There is deliberately no service to mount a disk. The system mounts one
before its first prompt, and a program mounting it again was only ever a
consequence of owning a second copy of the library, so that call disappears
rather than moving. Apps/Files.asm writes, reads, renames and deletes a file
in 645 bytes and includes nothing but the service names.
THE MONITOR. Previously an application, now part of the shell, because an
application occupies the one region a loaded application is given: a monitor
that was an application could never examine another one, since loading the
thing to be inspected would replace the thing doing the inspecting.
"monitor" turns it on and the prompt becomes "*". It is a mode rather than a
sub-prompt, and it persists: because the mode is a variable the prompt reads
rather than a second loop, and every path back to the prompt goes through one
place including osExit, a program started with "g" that gives the machine back
arrives at the monitor prompt it was started from. Examining a program and
running it therefore do not interrupt each other. "exit" leaves whatever you
are in.
It supersedes dump, and adds disassembly, writing bytes, and jumping to an
address. Its instruction table is generated from the assembler's own list by
Tests/instructiontable.py rather than typed again, and Tests/docs.sh checks
both that the system's copy matches the generator and that the lengths that
table implies are the ones the manual's Bytes column prints. A disassembler
that disagreed about a length would not print one line wrong, it would lose
its place and print everything after it wrong.
Also here: b refuses a bank that is not registered, since asking the
controller for one is refused and a refusal nobody catches stops the machine;
g records the Stack the way run does, without which a program returning
through osExit restored whatever the last run had left; and make cosmos-disk
now depends on the system as well as the image.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
sbfsFind counts a block's eight entries in SbfsCount and calls
sbfsMatchEntry for each one, and sbfsMatchEntry used the same variable for
its own twenty two byte comparison. A name differing at its first byte
returned without decrementing, leaving 22 in the entry counter, so the
search then walked twenty two entries through a buffer holding eight: off
the end of it, into whatever data happened to follow, matching against
rubbish and reporting a file that is not there as found.
It had always been there. What decided whether it looked like it worked
was the bytes after SbfsBuffer, so it stayed hidden until unrelated data
was added and changed them. It showed up as "dir" followed by any failed
"load" reporting that the file could not be read rather than that it does
not exist.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
AnachronautandClaude Opus 5