Idea similar to _exit

[a740g]

The assembly code I am using to trap x1b and x05 is this:

Code: (Select All)

;Traps and ignores Print-Screen and Control-Break. v1.1a PD 2020.

;Compiled with 'Tasm /t Keytrap;'

;Compile calling program using /fs with BC. (QBX forces /fs).

            .model  medium, basic          ;Stay compatible with basic.
    extrn  SETUEVENT: far
            .code
public      SETINT

SETINT      proc    uses ds
            mov    ax, 351BH              ;Get old control-break interrupt
            int    21h                    ;vector and save it.
            mov    word ptr cs:OldVector1,bx
            mov    word ptr cs:OldVector1+2,es
            push    cs                      ;Set the new
            pop    ds                      ;interrupt vector
            lea    dx, EventHandler        ;to the address
            mov    ax, 251BH              ;of our service
            int    21H                    ;routine.

            mov    ax, 3505H              ;Get old print-screen interrupt
            int    21h                    ;vector and save it.
            mov    word ptr cs:OldVector2,bx
            mov    word ptr cs:OldVector2+2,es
            push    cs                      ;Set the new
            pop    ds                      ;interrupt vector
            lea    dx, EventHandler        ;to the address
            mov    ax, 2505H              ;of our service
            int    21H                    ;routine.
            ret
SETINT     endp

public  EVENTHANDLER

EVENTHANDLER    proc
            iret                            ;eat keystroke. pop stack.

OldVector1  dd      0                      ;keep data in code segment.
OldVector2  dd      0

EVENTHANDLER endp

public      RESTINT

RESTINT    proc    uses ds                ;Restore the old
            lds    dx, cs:OldVector1      ;interrupt vectors
            mov    ax, 251BH              ;so things will
            int    21h                    ;keep working when
            lds    dx, cs:OldVector2      ;this basic program is
            mov    ax, 2505H              ;finished.
            int    21h
            ret
RESTINT    endp
            end

This looks like real mode x86 ASM. Brings back a lot of old memories.  None of this stuff is going to work with QB64 though because QB64 works under protected mode operating systems that does not allow you to use interrupts like we could with DOS. You'll need to use the appropriate OS APIs to achieve what you are trying to do. I would suggest looking at what @Spriggsy said if you are writing your code for Windows. I am quite certain that there are relevant APIs for Linux and macOS too. However, I am not too familiar with those OSes.