josephs@ttidcb.UUCP (Bill Josephs) (10/22/85)
Does anyone know (rhetoric question -- more correct: who knows and who
will tell me) how, an interrupt routine which is monitoring int 16
BIOS calls (a la the desk program in last month's byte magazine) can
tell whether COMMAND.COM issued the call or some other resident pro-
cess?
My problem is this: I can't take the memory cost of Superkey and
other pop up macro programs when all I need is a couple of canned
playback macros and a screen blank procedure. Using the Byte pro-
cedure, I've constructed my own which takes all of 600 bytes (in lieu
of 50K). It monitors interrupts 8 and 9 for screen blanking and 16
for keyboard requests (being careful, of course, to handle ah=0 and
ah=1 cases properly). However, Superkey knows if COMMAND.COM issued
the int 16 or some other process -- (it only saves "commands" in the
command stack -- user input in not saved). My question, How?
Thanks in advance.
Bill Josephs
CITICORP/TTI
3100 Ocean Park Blvd.
Santa Monica, Ca. 90405
(213) 450-9111slerner@sesame.UUCP (Simcha-Yitzchak Lerner) (10/24/85)
> > Does anyone know (rhetoric question -- more correct: who knows and who > will tell me) how, an interrupt routine which is monitoring int 16 > BIOS calls (a la the desk program in last month's byte magazine) can > tell whether COMMAND.COM issued the call or some other resident pro- > cess? > (Aha! Another case for SuperHacker!) I suggest you look at the CS value on the stack when you are called. -- Opinions expressed are public domain, and do not belong to Lotus Development Corp. ---------------------------------------------------------------- Simcha-Yitzchak Lerner {genrad|ihnp4|ima}!wjh12!talcott!sesame!slerner {cbosgd|harvard}!talcott!sesame!slerner talcott!sesame!slerner@harvard.ARPA