Timer Resolution Using Alsys

Timer Resolution Using Alsys

[DRAI]

Hello,

I am wondering if anyone can suggest a solution to the following problem:

I am using the Alsys compiler for DOS on a PC and would like to get a timer
resolution of at least 1 kHz, instead of the default 18.2 Hz provided by the
BIOS.  Tinkering with the PC's internal 8253 timer chip didn't work as the
Alsys runtime kernel already uses the interrupt (IRQ 8) from this chip.

Has anybody come across a similar problem?

Any help would be greatly appreciated.


Dave Rai

Re: Timer Resolution Using Alsys

[John Lo]

DRAI@SPAR.CA writes:

>I am using the Alsys compiler for DOS on a PC and would like to get a timer
>resolution of at least 1 kHz, instead of the default 18.2 Hz provided by the
>BIOS.  Tinkering with the PC's internal 8253 timer chip didn't work as the
>Alsys runtime kernel already uses the interrupt (IRQ 8) from this chip.

Try binding your Ada program with the binder option TIMER => FAST. This will cause
the Ada runtime to reprogram the timer to around 1 KHz resolution.

John Lo

Timer Resolution Using Alsys

[tmoran]

If you can't tinker with or even read the 8253, you might try a
background routine that just sends garbage data out a serial port at
9600 baud.  That will generate an interrupt at roughly 1KHz which
you can use to run a clock or whatever.