AnachronautandClaude Opus 5
588e02aff5
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
86 lines
1.7 KiB
NASM
86 lines
1.7 KiB
NASM
; The source reader on its own, before anything is built on top of it.
|
|
;
|
|
; Everything else in the assembler reads its source through srcNext, so a fault in here
|
|
; would turn up later as a mysterious wrong byte in an output file. It is worth checking by
|
|
; itself, against a file whose contents are already known.
|
|
;
|
|
; It reads whatever it was told to, prints every character back, and then says how many
|
|
; lines went past. The file it is given is deliberately bigger than one block, so the seam
|
|
; between one block and the next is crossed rather than assumed.
|
|
;
|
|
; Written by Anachronaut
|
|
|
|
#Include services.asm
|
|
|
|
#Program
|
|
|
|
#Base 0x4000
|
|
|
|
start:
|
|
SETD.0 Wanted
|
|
INIB 0d23
|
|
SWI osArgument
|
|
SETD.0 Wanted
|
|
LDA.0
|
|
BRA nothingAsked
|
|
|
|
SETD.0 Wanted
|
|
CALL srcOpen
|
|
BNQ noFile
|
|
|
|
readLoop:
|
|
CALL srcNext
|
|
BNQ readDone
|
|
SETD.0 SrcChar
|
|
LDA.0
|
|
OUTA 0x00 ; Straight to the console: one character is not a string.
|
|
BRI readLoop
|
|
|
|
readDone:
|
|
SETD.0 LinesText
|
|
SWI osPrintString
|
|
SETD.0 SrcLine
|
|
LDA.0
|
|
INCD.0
|
|
LDB.0
|
|
SWI osPrintNumber
|
|
SETD.0 NewLine
|
|
SWI osPrintString
|
|
SWI osExit
|
|
|
|
nothingAsked:
|
|
SETD.0 AskText
|
|
SWI osPrintString
|
|
SWI osExit
|
|
|
|
noFile:
|
|
SETD.0 NoFileText
|
|
SWI osPrintString
|
|
SWI osExit
|
|
|
|
#Data
|
|
|
|
#Base 0x2000
|
|
|
|
Wanted:
|
|
#Reserve 0d23
|
|
|
|
LinesText:
|
|
"---- lines: "
|
|
NewLine:
|
|
"
|
|
"
|
|
AskText:
|
|
"say which file
|
|
"
|
|
NoFileText:
|
|
"no such file
|
|
"
|
|
|
|
; The libraries go last, after both segments have been based. An included file that carries
|
|
; code brings its own #Program and #Data lines with it, and a #Base has to come before
|
|
; anything is in the segment it bases - so the bases are set here and the code arrives after.
|
|
#Include scratch.asm
|
|
#Include numbers.asm
|
|
#Include source.asm
|