🚀 go-pugleaf

vincent@datmuc.UUCP (vincent) writes:

>This is a (re)repost I never got any replys, The Org. Q. was why this code
>doesn't work?

[Lot's of text and code deleted....]

>P.P.P.S. I will continue on my side like instead of allocating a stack,
>have a fix buffer in the code segment. Also to date I'm not shure
>if I need to save the DS since it is anyway restore at the interrupt.
>Also in the inline asembly I might try to set ds to cs (for my data) and
>also for the stack seg.. (I guess I do need my own stack). The only thing I know
>about .COM is that LINK tell me that for tiny memory model I am not alowed
>to have _far pointers.

In the very few TSRs I have written (all in assembly, I'm afraid), I
save ALL registers I use, especially segment registers, like DS.
I never made my own stack, but the TSRs I wrote were also of the clock
interrupt type, and did not perform stack intensive operations,
though I did PUSH a few registers, including DS.
I did set DS = CS  upon entering the clock interrupt so I could get at
my own data easier, just remember to save DS before assigning it.

If you wish, I will post one of my TSRs for you to look at, but remember
that it is completely in 8088 assembly, and I am not a CS major. The
program might not be as efficient as possible, however it is quite
stable and will not crash very easily.

- Brian  (smithbm@craft.camp.clarkson.edu)

As for my opinion for why it crashes, try saving all registers used
in the interrupt routine. At least you will be at a "known state" and
can go from there. Just remember to POP all registers in reverse order
at the end of your routine.