[Coco] 6820 and 6821 pin compatible?
jcewy at swbell.net
Thu Nov 5 22:33:45 EST 2009
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
More information about the Coco