Mail Archives: djgpp/1994/09/15/02:36:45
Hi,
I am trying to write an interrupt handler for the PC serial port. I
tried the following and have the system stopped on various errors eg.
"0x0d not installed" and "protection faults"
a. install a real-mode interrupt using a real-mode callback iret wrapper
for my handler writtened in C
b. install a protected mode interrupt handler using a pm-iret-wrapper for
my C handler
c. install both the above, I read somewhere that it will save CPU time
in that it does not have to switch modes during the interrupt ???
All 3 programs will crash out after a few characters received, with (a)
being the most stable. I also seem to get overrun errors on the receive.
(c) doesn't seemed to work (double characters) as I believe that GO32
will always call the rm-handler as well.
BTW, I went throught DJASYNC codes which installed a serial interrupt in
rm as a TSR. Is this the only solution ?
Thanks in advance for any help.
- Raw text -