[Coco] CoCo's TIMER and 60hz

Dave Philipsen dave at davebiz.com
Thu May 30 09:51:03 EDT 2019

Yeah, it seems like the only way you’d have a problem is if the CPU was halted for long enough that it missed an IRQ or if the service routine was flawed in some way. 


> On May 30, 2019, at 8:21 AM, Mark McDougall <msmcdoug at iinet.net.au> wrote:
>> On 30/05/2019 3:14 am, Bill Nobel wrote:
>> The Coco3 was never accurate on software time due to fact the IRQ
>> line is shared with other devices besides VSYNC.  Yes they are queued
>> but arn’t serviced accurately based on time.
> I don't see how shared interrupts can contribute at all to drift? That would only occur if a countdown timer was only reset when the interrupt is actually serviced which, to my knowledge, can't be the case with the VSYNC.
> Regards,
> -- 
> Mark McDougall
> <http://retroports.blogspot.com.au>
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