Bios - Pc-98

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 = 24h AL = character (ASCII) BH = color (0–15, 0=black) INT 18h pc-98 bios

AH = 10h INT 18h Returns: AL = ASCII, AH = scancode AH = 41h DL = drive CX =

msg db 'Hello from PC-98 BIOS!', 0

; 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 write character mov bh

AH = 11h INT 18h ZF = 1 if no key ZF = 0 if key waiting → AX = scancode/ASCII

AH = 17h AL = rate (0–3Fh) INT 18h Set cursor position