DOS ain't dead - Using Multiple CPU Cores in DOS?

Using Multiple CPU Cores in DOS? (Miscellaneous)

posted by bretjohn , Rio Rancho, NM, 19.09.2011, 20:25

> Yes but I though that when accessing all mem >1MB in PM it use some native
> mode where all CPU address pins go directly to memory and A20 hack logic is
> disabled. I belived this is used only in real mode to access HMA. But I may
> be wrong.

Since I hadn't messed directly with PM before (all I had ever done was set up some Descriptor Table entries), I thought that as well. But now that I've done some testing, I know it's not true. A20 has to be enabled to access memory above 1 MB, even if the CPU is in PM. I tried it with A20 disabled -- it didn't crash, but the data was garbage.

Post reply

Complete thread:

Using Multiple CPU Cores in DOS? - bretjohn, 12.09.2011, 02:15 (Miscellaneous)
- Using Multiple CPU Cores in DOS? - RayeR, 12.09.2011, 15:26
  - Using Multiple CPU Cores in DOS? - Laaca, 12.09.2011, 17:26
    - Using Multiple CPU Cores in DOS? - RayeR, 12.09.2011, 20:13
    - Using Multiple CPU Cores in DOS? - bretjohn, 12.09.2011, 22:36
      - Using Multiple CPU Cores in DOS? - RayeR, 13.09.2011, 00:33
        Using Multiple CPU Cores in DOS? - bretjohn, 13.09.2011, 04:25
        Using Multiple CPU Cores in DOS? - RayeR, 13.09.2011, 19:32
        Using Multiple CPU Cores in DOS? - Laaca, 13.09.2011, 21:12
        Using Multiple CPU Cores in DOS? - bretjohn, 13.09.2011, 23:02
        Using Multiple CPU Cores in DOS? - RayeR, 14.09.2011, 03:30
        Using Multiple CPU Cores in DOS? - bretjohn, 14.09.2011, 18:24
        Using Multiple CPU Cores in DOS? - RayeR, 15.09.2011, 01:15
        Using Multiple CPU Cores in DOS? - bretjohn, 15.09.2011, 19:11
      - Using Multiple CPU Cores in DOS? - Rugxulo, 13.09.2011, 02:27
        Using Multiple CPU Cores in DOS? - RayeR, 14.09.2011, 03:52
      - Using Multiple CPU Cores in DOS? - tom, 14.09.2011, 13:24
        Using Multiple CPU Cores in DOS? - bretjohn, 14.09.2011, 19:03
        Using Multiple CPU Cores in DOS? - tom, 15.09.2011, 14:43
        Using Multiple CPU Cores in DOS? - bretjohn, 15.09.2011, 18:24
        Using Multiple CPU Cores in DOS? - tom, 15.09.2011, 18:40
        Using Multiple CPU Cores in DOS? - bretjohn, 16.09.2011, 01:33
        Using Multiple CPU Cores in DOS? - RayeR, 16.09.2011, 02:26
        Using Multiple CPU Cores in DOS? - bretjohn, 16.09.2011, 18:06
        Using Multiple CPU Cores in DOS? - RayeR, 16.09.2011, 18:22
        Using Multiple CPU Cores in DOS? - bretjohn, 17.09.2011, 02:03
        Using Multiple CPU Cores in DOS? - Laaca, 17.09.2011, 07:47
        Using Multiple CPU Cores in DOS? - tom, 17.09.2011, 14:09
        Using Multiple CPU Cores in DOS? - bretjohn, 18.09.2011, 04:27
        Using Multiple CPU Cores in DOS? - tom, 19.09.2011, 15:03
        Using Multiple CPU Cores in DOS? - bretjohn, 19.09.2011, 19:50
        Using Multiple CPU Cores in DOS? - tom, 19.09.2011, 22:00
        Using Multiple CPU Cores in DOS? - bretjohn, 19.09.2011, 23:19
        Using Multiple CPU Cores in DOS? - tom, 20.09.2011, 12:02
        Using Multiple CPU Cores in DOS? - DOS386, 20.09.2011, 12:24
        Using Multiple CPU Cores in DOS? - bretjohn, 20.09.2011, 18:23
        Using Multiple CPU Cores in DOS? - tom, 20.09.2011, 20:17
        Using Multiple CPU Cores in DOS? - RayeR, 19.09.2011, 15:01
        Using Multiple CPU Cores in DOS? - bretjohn, 19.09.2011, 20:25
        Using Multiple CPU Cores in DOS? - RayeR, 20.09.2011, 03:14
- Using Multiple CPU Cores in DOS? - DOS386, 13.09.2011, 07:11
  - Using Multiple CPU Cores in DOS? - bretjohn, 13.09.2011, 19:14
  - Using Multiple CPU Cores in DOS? - FFK, 18.09.2011, 04:44
    - Using Multiple CPU Cores in DOS? - RayeR, 19.09.2011, 14:50
      - Using Multiple CPU Cores in DOS? - FFK, 21.09.2011, 01:30
- USBDOS | A20-BUG | no need for 1'000'000'000 cores - DOS386, 20.09.2011, 09:10
  - USBDOS | A20-BUG | no need for 1'000'000'000 cores - bretjohn, 20.09.2011, 19:34
- Using Multiple CPU Cores in DOS? - RayeR, 23.09.2011, 02:27