AH = 40h DL = drive (0=A, 1=B, etc.) INT 18h Returns: CF = 0 if OK
; NASM syntax, PC-98 target ORG 100h start: mov ah, 24h ; write character mov bh, 7 ; gray on black mov si, msg .loop: lodsb test al, al jz done mov al, al int 18h jmp .loop done: ret
AH = 12h INT 18h
AH = 17h AL = rate (0–3Fh) INT 18h Set cursor position
AH = 71h INT 18h Returns: AX = KB of RAM (usually 640) pc-98 bios
AH = 41h DL = drive CX = track number (0–79 for 2HD) DH = head (0 or 1) CH = sector number (1–8 for 2HD) AL = number of sectors ES:BX = buffer INT 18h Returns: CF = 0 if OK
AH = 42h (same registers as read)
AH = 29h Returns: AL = current mode Reset disk system