Turbo C question
Scott Amspoker
scott at bbxsda.UUCP
Fri Oct 13 08:22:23 AEST 1989
I have a stange question about Turbo C.
I am doing a realtime MIDI application (using Turbo C) with an
interval timer interrupting about once a millisecond. I noticed
while doing an experiment one evening that fewer "ticks" were taking
place over the period of about a minute than expected. After considerable
investigation I determined that the less output I did to the screen,
the more accurate my counter. If I did no output at all, the timer
was accurate down to the tick. I concluded that something in the
putch() call in Turbo C was causing me to miss an occasional interrupt.
I figured this would happen if they had disabled the interrupts for
longer than one of my timer intervals.
Does this make sense? The machine I am using is a Yamaha C1 which is
*extremely* compatible with a 286-based PC. However, its LCD display
looks like a CGA to the software. Is it possible putch() is waiting
for the horizontal retrace with the interrupts disabled? This is not
necessary as it was with older CGA's.
Thanks
--
Scott Amspoker
Basis International, Albuquerque, NM
(505) 345-5232
unmvax.cs.unm.edu!bbx!bbxsda!scott
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