[Coco] OS-9 Level1 Version 02.00.00 FYI

[Walter Zambotti]

My testing of ovcc shows that at stock 1.79mhz speed 300 Virqs which
should does take 5 secs on a real CoCo III takes 43 seconds on OVCC.
Worse as I change the mhz qreuency on OVCC the Virq rate changes.

It should never change regardless of frequency.

I'm looking through the code now to try and see how it works

Walter

On 2020-04-19 12:30, Walter Zambotti wrote:
> Dave
>
> I too suspect the video system is being used for generating keyboard
> interrupts in OS9 and I suspect the maximum number of interrupts per
> seconds than becomes the Virq rate.
>
> Doing some testing with trapping Virqs I can trap a maximum of 60 per
> second.  One side effect I have noticed is that when trapping Virqs at
> the rate of 60/sec (the max) no other keyboard signal is delivered to my
> application.  It is as if OS9 cannot queue more than one signal in that
> time period to the same task.
>
> If I limit trapping the Virqs to 30/sec than I begin to receive keyboard
> interrupts (ESC and shift-ESC) as well.
>
> Walter
>
> On 2020-04-17 23:41, Bill Pierce via Coco wrote:
>> Dave, it seems it's something involving what OS9 L1 does immediately after a key is pressed. Programs seem to run fine up to a key press. L1 v2.0 must do something different right after the key press as opposed to L2. This difference is triggering VCC to freeze. I assume some reg is being reset and VCC is not responding properly. The object would be to trace down what happens after a keypress, step by step, in both L1 & L2. This should tell us what L1 is stomping in VCC and then we could fix VCC.
>>
>>
>> -----Original Message-----
>> From: Dave Philipsen <dave at davebiz.com>
>> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>> Sent: Fri, Apr 17, 2020 11:10 am
>> Subject: Re: [Coco] OS-9 Level1 Version 02.00.00 FYI
>>
>> Actually keyboard interrupts are not used in OS9. The keyboard is scanned at a regular interval determined by the interrupt routine but it’s actually the video system which is generating the interrupts which OS9 also uses for multitasking.
>>
>> Dave
>>
>>
>>
>