I want to input a char in ASM compare it to a defined char and print a message if they are the same or retry if they aren't
Problem is that my code works on emu8086 but not on a VM:
mdp DB 'c$'
mov ah, 1h
On emu8086 it wait user to press a key and to press enter, on a VM (as a bootloader) I can't press any key.
Best How To :
You can't use MS-DOS services (INT 21h) in a bootloader. MS-DOS is an operating system, like Linux or Windows. Just like how you can't use Linux services before Linux has loaded, you can't use MS-DOS services before it has loaded.
In a bootloader you're restricted to using BIOS services (or accessing the hardware directly). You can use the BIOS service INT 16h, AH=00h to read the keyboard.