[Coco] OS-9 Level1 Version 02.00.00 FYI

[Bill Pierce]

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