1994.12.01 10:33 "Re: DOS port", by Soren Pingel Dalsgaard
Apologies if this is a FAQ -- I looked in the archives and the sources mentioned there, but could not find what I was after...
I don't think it is a FAQ.
- Has anyone ported the latest libtiff to MSDOS, specifically using MSC 7.0, 6.0 or the Visual C++ compiler?
Well I tried to see if it was possible. A major problem is that LibTIFF was written for UNIX computers with unlimited memory resources :-). A port to DOS will need some dos extender because huge amount of memory *may* be needed in order to read an image.
You need to change the tif_msdos.c file so that all functions, i.e. file read and file write will work even if they have to write more than 64Kb data. The same goes for the memcpy, memset, memcmp, malloc, realloc and free functions (_TIFF prepended).
Also you need to compile it so that all pointers are HUGE by default. The library may cast tdata_t pointers to pointers to any data type. So the default pointer type must be able to address more than 64Kb.
- Do you have a make file for one of the above, &/or notes on 16 vs 32 bit issues and which routines might need to be omitted or reworked?
There is a makefile but it is old and I don't think it can be used for much. The porting problem is not in the makefile but the machine specific module.
- If anyone has comments on some other DOS C compiler (32 bit?) that eases any of the potential problems, I'd love to hear about that too.
I know that gcc for dos will work. I compiled the tools some time ago and they worked for me. One good thing about this compiler is that it is free (available from oak.oakland.edu in pub/msdos/djgpp)
Soren Pingel Dalsgaard, Computer Science Department )\._..--....,---,
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