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Question for Phill (Prime)

Posted: Thu Mar 15, 2012 2:18 am
by zephyr
A question here for Phill (Prime) or anyone else that can help:

One of my CoCo's is a PAL CoCo 1 model 26-3002 with the chiclet type keyboard. It came factory sealed with 16K RAM + Color Basic 1.1 + Extended Basic 1.0. There is a number 20261007 on the motherboard by the power supply and I noticed a couple of jumpers marked 16K - 64K by the eight NEC D416C-2 RAM chips. What I want to know is how to identify which board type (D, E or F) is fitted and how to upgrade it to 64K RAM.

Can anyone help?

Regards,
Steve

Re: Question for Phill (Prime)

Posted: Thu Mar 15, 2012 8:27 am
by prime
Not sure on that one I seem to remember asking on the CoCo mailing list.

I think that the jumpers will allow you to fit 8x4164 RAM chips to give you 64K, you may have to do the decoder mod if it is an early board, in order to zuse the full 64K.

Cheers

Phill.7

Re: Question for Phill (Prime)

Posted: Thu Mar 15, 2012 1:21 pm
by zephyr

Re: Question for Phill (Prime)

Posted: Thu Mar 15, 2012 9:20 pm
by prime
Yeah they look ok, cirtainly fast enough, and more importantly they are 128 cycle refresh, which is what the SAM needs.

Cheers,

Phill.

Re: Question for Phill (Prime)

Posted: Thu Mar 15, 2012 10:48 pm
by zephyr
Thanks Phill. I'll order a set of those and wait (hopefully) for more tech help.

Re: Question for Phill (Prime)

Posted: Mon Apr 02, 2012 9:17 pm
by zephyr
OK, I did the 64K upgrade today and its working fine. The decoder mod wasn't needed. All three of my CoCo's now have 64K of RAM fitted. Thanks for taking the time to help me with this.

Regards,
Steve