[Coco] 6820 and 6821 pin compatible?

[Mike Pepe]

Should work just fine. As I recall the major difference between the two was the 6820 had dynamic registers while the 6821 was static. But I'm sure if I'm wrong someone will chime in.

> -----Original Message-----
> From: coco-bounces at maltedmedia.com [mailto:coco-
> bounces at maltedmedia.com] On Behalf Of Joel Ewy
> Sent: Thursday, November 05, 2009 7:34 PM
> To: CoCoList for Color Computer Enthusiasts
> Subject: [Coco] 6820 and 6821 pin compatible?
> 
> I'm restoring an SWTPC 6809 computer.  I intend to run OS-9 on it.  I
> also want to try out FLEX and UNIFLEX (the latter of which I'm sure
> this
> computer once ran).
> 
> I've got a timer board, that I believe (judging from the OS-9
> configuration of the SWTPC emulator) provides the system clock
> interrupts.  It has a socket that, according to the documentation, once
> housed a 6820, but now sits empty.  I can probably dig up the
> documentation, but I bet somebody on this list can tell me without
> cracking a book or downloading a PDF whether or not I can just plop a
> much more readily available 6821 in there instead.
> 
> If you're interested in following my progress on this project, I've
> been
> blogging about it:  http://8littlebits.wordpress.com/category/swtpc/
> 
> The CoCo gets mentioned as well, and I used a CoCo emulator to make a
> boot disk image I'll eventually use when I'm ready to try and boot this
> thing up.
> 
> JCE
> 
> 
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco