DOS ain't dead

DX64 - open source 64-bit ring 0 dos extender (Announce)

posted by Japheth , Germany (South), 25.03.2020, 16:28

> I tested programs with QEMU and Bochs and they work for me.

Well, good, at least Qemu works "for me" also - didn't test Box.

However, the qemu keyboard emulation was "not so good" in 2007 when I played with it ( the HX Win32 emulation needs pretty low level access to the keyboard ) and my impression is that it hasn't improved much in the last 13 years. At the very least you shouldn't rely on qemu if you want your program to run elsewhere as well.

> You can use the SD64.EXE debugger and trace the programs.

Thanks, but this debugger shows just a black screen when I start it (in qemu and in true DOS ).

I was curious and took a brief look into Hello64.asm ( I didn't try to assemble because you mentioned that a "special" version of fasm is needed ). This code looks suspicious:


Int09h: inc     dword [dword 0xB8000+ScreenX*8]
        iretq

Int08h: push    rax
        inc     dword [dword 0xB8000+ScreenX*0]
        in      al,60h          ;Get char from keyboard
        cmp     al,81h          ;Esc released?
ifz     mov     [WasCtrlBreak],80h ; if yes, be ready from exit


It's probably a typo, but the keyboard is usually read by Int09 and the timer is handled by Int08 - your code looks as if you've mixed up those.

---
MS-DOS forever!

Complete thread:

• DX64 - open source 64-bit ring 0 dos extender - CandyMan, 25.02.2019, 11:42 (Announce)
  • DX64 - open source 64-bit ring 0 dos extender - Laaca, 07.03.2019, 21:32
    • DX64 - open source 64-bit ring 0 dos extender - CandyMan, 09.03.2019, 11:58
  • DX64 - open source 64-bit ring 0 dos extender - Japheth, 16.03.2020, 07:47
    • DX64 - open source 64-bit ring 0 dos extender - CandyMan, 23.03.2020, 11:30
      • DX64 - open source 64-bit ring 0 dos extender - Japheth, 23.03.2020, 20:24
        • DX64 - open source 64-bit ring 0 dos extender - CandyMan, 24.03.2020, 19:56
          • DX64 - open source 64-bit ring 0 dos extender - Japheth, 25.03.2020, 16:28
            • DX64 - open source 64-bit ring 0 dos extender - CandyMan, 25.03.2020, 18:34
              • DX64 - open source 64-bit ring 0 dos extender - Japheth, 27.03.2020, 13:07
                • DX64 - open source 64-bit ring 0 dos extender - Laaca, 27.03.2020, 15:58
                  • DX64 - open source 64-bit ring 0 dos extender - Japheth, 27.03.2020, 16:15
                • DX64 - open source 64-bit ring 0 dos extender - CandyMan, 27.03.2020, 18:57
                  • DX64 - open source 64-bit ring 0 dos extender - Japheth, 30.03.2020, 05:36
            • DX64 - open source 64-bit ring 0 dos extender - RayeR, 18.01.2022, 03:40
  • DX64 - open source 64-bit ring 0 dos extender - Gianlu1950, 17.01.2022, 01:54
    • DX64 - open source 64-bit ring 0 dos extender - Laaca, 17.01.2022, 16:47
      • DX64 - open source 64-bit ring 0 dos extender - Gianlu1950, 18.01.2022, 02:02
    • DX64 - open source 64-bit ring 0 dos extender - Khusraw, 05.02.2022, 13:57
      • DX64 - open source 64-bit ring 0 dos extender - Gianlu1950, 12.02.2022, 01:50
  • DX64 - open source 64-bit ring 0 dos extender - DosWorld, 30.01.2022, 18:40
    • DX64 - open source 64-bit ring 0 dos extender - DosWorld, 31.01.2022, 18:35