DOS ain't dead

How to keep resident only a part of the program (Developers)

posted by rr  , Berlin, Germany, 08.03.2022, 17:32

> I succeeded to solve this problem!



> It is possible to create a big program in the Turbopascal and keep only a
> tiny TSR in the memory and unloaded the rest.
> The practical implementation I used here.
>
> The principle is to write a small assembler procedure which will be used as
> a TSR. In this procedure keep a area which will be modified on the fly to
> store there some data.
> Then move this procedure/module just after PSP of the main program.
> (PSP+256)
> Now is it a little bit dangerous because a part of the pascal system
> library is overwritten so it is not safe to call many RTL functions.
> In assembler redirect the calling interrupt vector to PSP+256
> Then call the DOS function 31h and into DX store the 16+TSR_size/16.
> And it works

A bit late, because you already solved it, but https://github.com/FDOS/keyb might be of interest.

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Complete thread:

• How to keep resident only a part of the program - Laaca, 14.08.2021, 07:31 (Developers)
  • How to keep resident only a part of the program - tkchia, 14.08.2021, 08:49
    • How to keep resident only a part of the program - Laaca, 14.08.2021, 10:32
      • How to keep resident only a part of the program - tom, 14.08.2021, 11:40
        • How to keep resident only a part of the program - RayeR, 14.08.2021, 15:49
          • How to keep resident only a part of the program - Laaca, 14.08.2021, 20:18
            • How to keep resident only a part of the program - RayeR, 16.08.2021, 03:22
    • How to keep resident only a part of the program - tom, 14.08.2021, 11:28
    • How to keep resident only a part of the program - ecm, 15.08.2021, 13:47
      • How to keep resident only a part of the program - bretjohn, 27.08.2021, 21:22
  • How to keep resident only a part of the program - marcov, 14.08.2021, 13:18
  • How to keep resident only a part of the program - CandyMan, 27.08.2021, 17:46
  • How to keep resident only a part of the program - bretjohn, 27.08.2021, 21:47
  • How to keep resident only a part of the program - Laaca, 08.03.2022, 12:24
    • How to keep resident only a part of the program - tom, 08.03.2022, 12:51
      • How to keep resident only a part of the program - tkchia, 08.03.2022, 14:20
        • How to keep resident only a part of the program - bretjohn, 08.03.2022, 19:19
    • How to keep resident only a part of the program - rr, 08.03.2022, 17:32