Pc-98 Bios

AH = 21h DH = row (0–24 or 0–27) DL = column (0–79) INT 18h

The PC-98 BIOS relies on the 8253/8254 timer chips. Unlike an IBM PC, where the BIOS uses channel 0 for system timer, the PC-98 uses it for floppy data rate control. Wrong timing in an emulator leads to "Floppy disk controller ready timeout" errors. pc-98 bios

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 = 21h DH = row (0–24 or

The PC-98 BIOS functions as the bridge between software and the machine's distinct hardware components. While modern PCs rely on standardized IBM-compatible firmware, the PC-98 ecosystem used a different set of BIOS calls and memory management standards. start: mov ah, 24h ; write character mov