Add interrupts module: INT 3 (CC breakpoint) vs INT 21h (DOS services)

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
2026-09-30 19:10:56 +00:00
commit 09af523f8c
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+     1                                  ; opcodes.asm -- which bytes does each spelling assemble to?  (read the listing, never run)
+     2                                  bits 16
+     3                                  org 0x100
+     4 00000000 CC                          int3                    ; the one-byte breakpoint        -> CC
+     5 00000001 CD03                        int 3                   ; "INT n" with n = 3 in NASM      -> CD 03
+     6 00000003 CD03                        db 0CDh, 03h            ; the same two bytes, written out -> CD 03
+     7 00000005 CD21                        int 21h                 ; DOS entry point                 -> CD 21
+     8 00000007 CD10                        int 10h                 ; BIOS video                      -> CD 10
+     9 00000009 CE                          into                    ; one-byte INTO                   -> CE