DOS ain't dead

some TSR/patch to modify BIOS/EDD? (Users)

posted by RayeR , CZ, 30.04.2026, 17:31

I tried temporary switch to AHCI and it has different AHCI BIOS that supports EDD 3.0 and reports the correct value of total LBA sectors. WinNT4 with UniATA booted in AHCI mode without a problem bu they still see only 1,6TB so even when EDD fixed it is still truncated somewhere else so no need further EDD experiments...

I also tried to manually create another primary partition that fills the rest from 1,6TB to the end (under W7-x64) and found there's visible aliasing behind 2TB of absolute LBA address! So even that Windows sees this partition normally it would cause data loss when I try to write there. The same in Win98 and DOS7/FreeDOS. So it doesn't make sense to expose 2nd partition in MBR to legacy OSes but safer would be if it will be defined only in GPT for newer OSes only (via hybrid MBR).

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DOS gives me freedom to unlimited HW access.

Complete thread:

• Partitioning of 4TB HDD for legacy OSes - RayeR, 27.04.2026, 22:45 (Users)
  • Partitioning of 4TB HDD for legacy OSes - mceric, 28.04.2026, 01:35
    • Partitioning of 4TB HDD for legacy OSes - bretjohn, 28.04.2026, 03:04
      • Partitioning of 4TB HDD for legacy OSes - Laaca, 28.04.2026, 05:08
        • Partitioning of 4TB HDD for legacy OSes - RayeR, 28.04.2026, 17:28
          • Partitioning of 4TB HDD for legacy OSes - Rugxulo, 29.04.2026, 05:23
            • Partitioning of 4TB HDD for legacy OSes - RayeR, 29.04.2026, 20:09
        • Partitioning of 4TB HDD for legacy OSes - bretjohn, 28.04.2026, 17:30
          • Partitioning of 4TB HDD for legacy OSes - Laaca, 28.04.2026, 18:31
            • Partitioning of 4TB HDD for legacy OSes - RayeR, 28.04.2026, 20:31
    • Partitioning of 4TB HDD for legacy OSes - RayeR, 28.04.2026, 17:21
  • Partitioning of 4TB HDD for legacy OSes - Zyzzle, 29.04.2026, 01:39
    • Partitioning of 4TB HDD for legacy OSes - bretjohn, 29.04.2026, 03:39
    • some TSR/patch to modify BIOS/EDD? - RayeR, 29.04.2026, 20:20
      • some TSR/patch to modify BIOS/EDD? - ecm, 29.04.2026, 20:56
        • some TSR/patch to modify BIOS/EDD? - RayeR, 30.04.2026, 17:31
          • some TSR/patch to modify BIOS/EDD? - ecm, 30.04.2026, 20:06
          • some TSR/patch to modify BIOS/EDD? - Laaca, 01.05.2026, 12:24
          • some TSR/patch to modify BIOS/EDD? - RayeR, 04.05.2026, 17:48
            • failed with hybrid MBR under Windows - RayeR, 07.05.2026, 15:40
              • failed with hybrid MBR under Windows - bretjohn, 07.05.2026, 22:36
                • failed with hybrid MBR under Windows - RayeR, 09.05.2026, 18:16
                  • failed with hybrid MBR under Windows - RayeR, 11.05.2026, 07:47
                    • New Idea how to beak 2TB on WinXP-32 - RayeR, 23.05.2026, 13:51