From:	"Bertel k. Brander" <bertel AT post4 DOT tele DOT dk>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Interrupts and locking code
Date:	Thu, 03 Apr 1997 02:52:12 +0100
Lines:	19
Message-ID:	<33430D4C.1D69@post4.tele.dk>
NNTP-Posting-Host:	kbh1-1.kbh.tele.dk
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Hi

I have tryed to port a BorlandC C program to DJGPP, because i have to use more memory than the first 640k, but 
i ran in to some problems which i hope you can help me with.

1. 
I have two interrupts, one for the timer tick (dos interrupt 8) and a uart (serial) interrupt, the interrupt 
handlers uses a lot of data and a lot of functions. Is there a simle way to lock all this data and code? Can i 
lock all code and all static (not dynamic allocated) data, and then only use the extended memory for dynamic 
allocated memory? (The data allocated dynamically is not accesed from interrupts.) When i lock memory for 
functions how do i then know the size of the function?

2. The program reprograms the timer, so that the clock tick interrupt is raised every 0.5 ms insted of the 
normal 55ms, then, in order to have the real time clock on the PC running at the right speed, i must call the 
orignal dos handler once for every 109 timer tick interrupt. How do i do that?

Best regards

bertel AT post4 DOT tele DOT dk

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