DOS ain't dead

PIC (Announce)

posted by DOS386, 20.06.2008, 09:23

> I have few questions about position independent code.

ANSWER (general, not FP-related)

> 1) what is it?

Code than can run at any address, needs neither to:

- sit at ZERO or fixed address in a private segment like DOS COM 16-bit RM (0) or DGJPP / FPC-GO32 (0) or Win32-PE-EXE ($400000)
nor
- use silly fixups (partially MZ DOS EXE, WATCOM/LE, PE-DLL)

> 2) what is it good for?

Avoiding segmentation and fixups, using shared libs / objects / drivers ( YES - DOS needs reusable 32-bit PIC drivers :hungry: )

> 3) has it got any meaning for DOS?

YES, see above.

> 4) how can I use assembler with it?

Reserve one register ( EBX ? or FP will decide for you ?) for global base, and index all global vars with it.

call varbase ; & MOVNTQ EBX,EIP varbase: pope ebx ; & ; inc byte [blah] inc byte [blah-varbase+ebx]

> (it gives an error in assignments like MOV GLOBAL_VARIABLE,1)

Because absolute addrs are prohibited, see above.

---
This is a LOGITECH mouse driver, but some software expect here
the following string:*** This is Copyright 1983 Microsoft ***

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Complete thread:

Free Pascal version 2.2.2 release candidate 1 available - marcov, 17.06.2008, 12:24 (Announce)
- Free Pascal version 2.2.2 release candidate 1 available - Laaca, 19.06.2008, 00:33
  - Free Pascal version 2.2.2 release candidate 1 available - DOS386, 19.06.2008, 08:27
  - Free Pascal version 2.2.2 release candidate 1 available - marcov, 19.06.2008, 11:15
  - Free Pascal version 2.2.2 release candidate 1 available - marcov, 19.06.2008, 11:28
    - Free Pascal version 2.2.2 release candidate 1 available - Laaca, 19.06.2008, 21:56
      - Free Pascal version 2.2.2 release candidate 1 available - marcov, 21.06.2008, 15:32
- Free Pascal version 2.2.2 release candidate 1 available - Laaca, 19.06.2008, 22:14
  - PIC - DOS386, 20.06.2008, 09:23
    - No PIC - Japheth, 20.06.2008, 20:22
      - No PIC - marcov, 21.06.2008, 14:00
        No PIC - ecm, 21.06.2008, 21:48
        No PIC - marcov, 22.06.2008, 11:49
      - No PIC | bullshit | CRAP - DOS386, 20.08.2008, 08:10
        No PIC | bullshit | CRAP - Japheth, 20.08.2008, 10:24
    - PIC - marcov, 21.06.2008, 13:54