PASS  int3 assembles to the single byte CC
PASS  NASM 'int 3' assembles to CD 03
PASS  int 21h assembles to CD 21
PASS  into assembles to CE
PASS  hello21 prints its string
PASS  AH=4Ch return code 7 visible as ERRORLEVEL
PASS  AH=30h reports a version
PASS  AH=2Ah/2Ch ranges ok
PASS  AH=02h+06h write AB
PASS  AH=01h returned 5A ('Z') and AH=0Ah counted 5 chars 'Ankur'
PASS  AH=25h/35h round trip
PASS  AH=48h/49h alloc+free ok
PASS  AH=48h 1 MB request fails CF=1 AX=0008
PASS  file I/O: 12 bytes read, LSEEK says 12
PASS  findfirst sees U.TXT size 12
PASS  reopening deleted file: CF=1 AX=0002
PASS  mkdir/rmdir ok
PASS  child exit code 7, termination type 0 via AH=4Dh
PASS  CC: return IP = trap + 1
PASS  CD 03: return IP = trap + 2
PASS  IF and TF are 0 inside the handler, IF back to 1 after IRET
PASS  IF pushed on the stack was 1
PASS  INT 3 with no handler: program survives under DOSBox
PASS  DEBUG + CC: 'Unexpected breakpoint interrupt' and IP=0104
PASS  DEBUG + CC: next instruction after trap is MOV AX,2222
PASS  DEBUG + CC: single-step then AX=2222
PASS  DEBUG + CD 03: no breakpoint message
PASS  DEBUG + CD 03: stops at IP=0104 inside the INT 03 instruction
PASS  DEBUG + CD 03: MOV AX,2222 never runs (AX stays 1111 after stepping)
PASS  Unicorn: CC patch trap return IP = site+1, resume gives CX=3
PASS  Unicorn: CD 03 patch trap return IP = site+2 and resume goes wrong