Maurice Lombardi wrote:

1 - djgpp is a linear frame 32 bits system. It does not know about Segment:Offset addresses.

2 - djgpp is a protected mode system libe BP (not TP): The address even in BP would be Selector:Offset instead of Segment:Offset. You would need to replace Const BiosSeg=$40 by Const BiosSeg=seg0040 (BP takes care to put the correct selector instead of $40 in seg0040).

3 - there are a lot of functions to address physical memory in the djgpp's libc: look at _dpmi... functions by info libc. But probably the simplest would be to look to _far* functions (_farpeekb etc...) to peek/poke values at such addresses with a minimum effort. You just have to declare these functions in your pascal program with asmname to make them known, e.g.

function farpeekb(selector:ShortWord; offset:MedWord): byte; asmname "_farpeekb";

please read carefully the explanation in the _far* section of the info libc on how to use these functions (get selectors...)

Besides, if you want to get the screen size, you can use `ScreenSize' in the CRT unit. For other things where you need to access BIOS variables in TP, there are also Pascal routines available in GPC.

Frank