[comp.os.msdos.programmer] Info wanted on 8253 chip

tanida@odin.css.gov (Tom Tanida) (08/14/90)

I am writing an application which needs 100ths of a second accurate
timing. Calls to the BIOS are not enough.  I have heard that accessing
the 8253 timer chip is the way to go, but I cannot find any
information on how to use the chip.  Can anybody out there let me know
of a good reference/source of info for this?

Thanks,
Tom

avi@pluto.dss.com (Avi Elenko) (08/16/90)

In article <570@esosun.UUCP>, tanida@odin.css.gov (Tom Tanida) writes:
> I am writing an application which needs 100ths of a second accurate
> timing. Calls to the BIOS are not enough.  I have heard that accessing
> the 8253 timer chip is the way to go, but I cannot find any
> information on how to use the chip.  Can anybody out there let me know
> of a good reference/source of info for this?
> 
> Thanks,
> Tom

Tom -

    You can try the following assembly code.

=== Top Of File ===
                     ; Program the 8254-2

    
    MOV AL,      24H ; Program high order
    OUT 43H,      AL ;
    MOV AL,       01 ; Once 100 micros
    OUT 40H,      AL ;
                     ;
    MOV AL,      14H ; Program low order
    OUT 43H,      AL ;
    MOV AL,     077H ;
    MOV 40H,      AL ;

=== Bottom Of File ===

rcollins@altos86.Altos.COM (Robert Collins) (08/20/90)

In article <570@esosun.UUCP> tanida@odin.css.gov (Tom Tanida) writes:
>the 8253 timer chip is the way to go, but I cannot find any
>information on how to use the chip.  Can anybody out there let me know
>of a good reference/source of info for this?


Look in the Intel Peripherals book PN  296467.
Since this is an Intel part, the Intel Peripherals book is the
definitive source.


-- 
"Worship the Lord your God, and serve him only."  Mat. 4:10
Robert Collins                 UUCP:  ...!sun!altos86!rcollins
HOME:  (408) 225-8002
WORK:  (408) 432-6200 x4356