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PET 2001N 16k upgrade ram

Posted: Mon Nov 26, 2018 8:30 am
by nai1ed
I just picked up a Commodore Pet 2001n with 16k and I see that there is a whole empty ram back to add more memory. The current memory installed is TMM416D-4 , but I have 8 ram chips form my old TRS-80 Color computer (8040016). Will I be able to use the 8040016 ram chips on this Pet?

Thanks

Brian

Re: PET 2001N 16k upgrade ram

Posted: Tue Nov 27, 2018 4:45 am
by LoneWolf33
Hi,

They're pin compatible, the TMM416D-4 has a bit slower access time: 250ns vs 200ns.
IMHO the spare ICs are suitable for the RAM upgrade.

Re: PET 2001N 16k upgrade ram

Posted: Tue Nov 27, 2018 6:35 am
by nai1ed
Thanks, I will give it a try then. I'm going to install dip sockets first, just incase they don't work. My other questions now is how do I configure the jumpers for the extra ram? Is there a guide on these jumpers?

Thanks

Re: PET 2001N 16k upgrade ram

Posted: Tue Nov 27, 2018 11:37 pm
by LoneWolf33
I've found an image at zimmers.net which describes the jumper/DIP switch configurations:
http://www.zimmers.net/anonftp/pub/cbm/ ... 0351-6.gif

I guess this fits for your PET2001N motherboard. If so, then it seems only SH2 DIP bank settings are need to be changed
in order to address the newly added 16k bank.

Re: PET 2001N 16k upgrade ram

Posted: Wed Nov 28, 2018 6:53 am
by nai1ed
Thank you, that's very helpful.