asmhatreandClaude Sonnet 5.5
09af523f8c
NASM sources, DOSBox/FreeDOS Debug/Unicorn harness, captured output and 31 assertions backing the ankurm.com article "INT 3 vs INT 21h in 8086 Assembly". Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01KqJyCidz3ZgRyHABv2GVJh
32 lines
1.4 KiB
Plaintext
32 lines
1.4 KiB
Plaintext
PASS int3 assembles to the single byte CC
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PASS NASM 'int 3' assembles to CD 03
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PASS int 21h assembles to CD 21
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PASS into assembles to CE
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PASS hello21 prints its string
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PASS AH=4Ch return code 7 visible as ERRORLEVEL
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PASS AH=30h reports a version
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PASS AH=2Ah/2Ch ranges ok
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PASS AH=02h+06h write AB
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PASS AH=01h returned 5A ('Z') and AH=0Ah counted 5 chars 'Ankur'
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PASS AH=25h/35h round trip
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PASS AH=48h/49h alloc+free ok
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PASS AH=48h 1 MB request fails CF=1 AX=0008
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PASS file I/O: 12 bytes read, LSEEK says 12
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PASS findfirst sees U.TXT size 12
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PASS reopening deleted file: CF=1 AX=0002
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PASS mkdir/rmdir ok
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PASS child exit code 7, termination type 0 via AH=4Dh
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PASS CC: return IP = trap + 1
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PASS CD 03: return IP = trap + 2
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PASS IF and TF are 0 inside the handler, IF back to 1 after IRET
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PASS IF pushed on the stack was 1
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PASS INT 3 with no handler: program survives under DOSBox
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PASS DEBUG + CC: 'Unexpected breakpoint interrupt' and IP=0104
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PASS DEBUG + CC: next instruction after trap is MOV AX,2222
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PASS DEBUG + CC: single-step then AX=2222
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PASS DEBUG + CD 03: no breakpoint message
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PASS DEBUG + CD 03: stops at IP=0104 inside the INT 03 instruction
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PASS DEBUG + CD 03: MOV AX,2222 never runs (AX stays 1111 after stepping)
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PASS Unicorn: CC patch trap return IP = site+1, resume gives CX=3
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PASS Unicorn: CD 03 patch trap return IP = site+2 and resume goes wrong
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