DOS ain't dead

Memory mapped devices from resl mode (Developers)

posted by marcov, 02.03.2020, 23:13

> With DJGPP the flag is not set by default in __crt0_startup_flags
> (see
> crt0.S),

Yes, and it does JZ after the test 0x80,,
16: testb $0x80, __crt0_startup_flags /* include/crt0.h */

But only if ax=8 int $31 followed by lsl returns -1 (and after incl ebx 0)

> normally you need to call
> __djgpp_nearptr_enable
> (see also
> nearptr.c).

These don't exist in normal Free Pascal programs. It is go32v2 only, not libc. But equivalents for the calls are probably in dpmi* and go32 units, just not as many of the symbolic constants.

But this is all 20 years ago for me

Complete thread:

• Memory mapped devices from resl mode - Laaca, 26.02.2020, 12:11 (Developers)
  • Memory mapped devices from resl mode - Khusraw, 26.02.2020, 12:35
  • Memory mapped devices from resl mode - RayeR, 27.02.2020, 05:27
    • Memory mapped devices from resl mode - Khusraw, 27.02.2020, 09:07
      • Memory mapped devices from resl mode - Laaca, 04.03.2020, 14:01
        • Memory mapped devices from resl mode - Khusraw, 04.03.2020, 15:02
          • Memory mapped devices from resl mode - Laaca, 04.03.2020, 15:08
            • Memory mapped devices from resl mode - Khusraw, 04.03.2020, 15:23
            • Memory mapped devices from resl mode - Khusraw, 04.03.2020, 15:36
            • Memory mapped devices from resl mode - Khusraw, 04.03.2020, 16:55
              • Memory mapped devices from resl mode - Laaca, 04.03.2020, 18:54
                • Memory mapped devices from resl mode - Khusraw, 04.03.2020, 19:33
    • Memory mapped devices from resl mode - Laaca, 27.02.2020, 17:50
      • Memory mapped devices from resl mode - Khusraw, 27.02.2020, 20:25
        • Memory mapped devices from resl mode - KormaX, 01.03.2020, 22:23
          • Memory mapped devices from resl mode - Zyzzle, 02.03.2020, 06:10
            • Memory mapped devices from resl mode - KormaX, 12.05.2020, 11:21
        • Memory mapped devices from resl mode - marcov, 02.03.2020, 15:43
          • Memory mapped devices from resl mode - Khusraw, 02.03.2020, 19:39
            • Memory mapped devices from resl mode - marcov, 02.03.2020, 23:13
              • Memory mapped devices from real mode - Rugxulo, 03.03.2020, 06:11
                • Memory mapped devices from real mode - marcov, 03.03.2020, 10:12
                  • Memory mapped devices from real mode - Rugxulo, 03.03.2020, 22:12
              • Memory mapped devices from resl mode - Khusraw, 03.03.2020, 13:34