[net.micro.atari16] How to use Xbtimer

glenn@sdcrdcf.UUCP (Glenn C. Scott) (07/10/86)

  Has anyone figured out how to use the Xbtimer() extended BIOS function ?
I would sure appreciate a kind soul telling me how to set up a timer, turn it
on and turn it off.

  I don't want to use the 200Hz system clock, I do want to use the A timer of
the 68901 via Xbtimer().

Thanks,
Glenn C. Scott
--------------------------------------------------------------------------------
Glenn C. Scott
System Development Corporation, 2525 Colorado Ave, Santa Monica, CA. 90406
213-820-4111 X5653      UUCP: glenn@sdcrdcf.UUCP   ARPA: Scott@DOCKMASTER.ARPA

paone@caip.UUCP (07/15/86)

C: void xbtimer(timer, control, data, vector)
   int timer,control, data;
   logn vector;

This function allows you to start a timer in the MFP 68901, timer 
is the number of the timer in the 68901. Timer A:0 Timer B:1 ect...

The other two dat and control are placed in the data and control
registers. The long parameter is the address of the interrupt routine.

I really think it would be more useful in assembly then C, but since I
don't have an assembler to use this I can't.


	Phil Paone

bammi@cwruecmp.UUCP (07/17/86)

> C: void xbtimer(timer, control, data, vector)
>    int timer,control, data;
>    logn vector;
> 
> This function allows you to start a timer in the MFP 68901, timer 
> is the number of the timer in the 68901. Timer A:0 Timer B:1 ect...
> 
> The other two dat and control are placed in the data and control
> registers. The long parameter is the address of the interrupt routine.
> 
> I really think it would be more useful in assembly then C, but since I
> don't have an assembler to use this I can't.
> 
> 
> 	Phil Paone

*** REPLACE THIS LINE WITH YOUR MESSAGE ***
Another point:
	The routine designated in the vector must return using RTE and
not RTS, as it is handling the intr. 

	Assembly can be imbedded in alcyon C by using the asm
construct like:
	
	asm("rte");

so you don't really need an assembler to force an RTE. I'll try and
dig up some samle Xbtimer code that i once wrote.
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