Mail Archives: djgpp/2000/01/09/12:13:51
Eli Zaretskii (eliz AT is DOT elta DOT co DOT il) wrote:
:
: On Thu, 6 Jan 100, Martin Str|mberg wrote:
:
: > > It should be easy to throw together a function that copies the string
: > > into a static buffer (together with any attribute byte, to make its tand
: > > out), then blits it all to video RAM. If you write this in assembly, you
: > > can forget about the stack.
: >
: > Well, that's far over my head. I just want to be able to hook INT31
: > and be able to get out some debug info (so I can see where the real
: > code goes wrong).
:
: How about using _farpokeb, then? It's inline assembly, and doesn't
: use the stack. You could write the characters with it one by one.
: Clumsy, but works.
:
: Actually, you could even use the assembly instructions from _farpokeb
: inlined in your code.
The problem I have isn't with the loop or such, but to get something
out to video memory. I have some kind of basic understanding of
assembly, but knows very little about PC hardware.
: Or, simply remove the call to cputs and see if the crashes stop. If
: they do, you know that this is the culprit. If they don't, it's
: probably a good idea to find and correct the other problem(s) before
: you actually do something useful with the hook.
Well, I did that with one of my earlier attempts, the crashing
stopped (no surprise as I didn't set up the segments correctly). If I
do that with my latest (simple9.c) the computer reboots.
The cputs call is only to get some debug information. If I only chain
all works. If I do some real work it doesn't work. So the next step is
a way to get debug information (cputs) but I can't make that work - so
I'm stuck. Help!
Right,
MartinS
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