Author Topic: Legacy Technology RAM Boards - A Question for UK Modders.  (Read 1663 times)

Offline Pete W.

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Legacy Technology RAM Boards - A Question for UK Modders.
« on: January 14, 2016, 04:52:43 AM »
Hi there, all,

I wrote 'all' but I guess this question is directed at UK Modders.

Back in August, 1980, I bought some printed circuit boards from the New Bear Computing Store in Newbury, Berkshire.  These boards, when populated, each supported 4 kB of static RAM, using 2102 or 21L02 chips plus some 'glue logic'.  The boards are physically similar in outline to those of the Motorola 'Exorciser' development system for the 6800 8-bit microprocessor.

Because of difficulties getting hold of other components for my project (e.g. a teleprinter as VDUs weren't available) I never assembled these RAM boards.  Amateur computer enthusiasts in those days didn't have access to stuff like keyboards, monitors and PSUs that have since become more easily available!

I still have both the boards and the 21L02 chips but I can't find any of the original New Bear circuit or assembly instructions.

So I'm posting this enquiry in case any other (UK) Modder still has any relevant New Bear documentation on file and would be prepared to copy or scan for me. 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline John Swift

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Re: Legacy Technology RAM Boards - A Question for UK Modders.
« Reply #1 on: January 14, 2016, 07:38:54 AM »

Hi Pete

just incase no one has the instructions for the  New Bear Computing  memory boards
widen the search to include other computers of that period

without the complication of dynamic refresh the boards will use a simple address decoding circuit that is likely to be very similar to other designs published in ETI , Practical electronics etc

http://ece-research.unm.edu/jimp/310/slides/8086_memory2.html

  John


Offline DMIOM

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Re: Legacy Technology RAM Boards - A Question for UK Modders.
« Reply #2 on: January 14, 2016, 11:26:26 AM »
Pete,

I can't help you directly, but there's another member - Trevor Brownen(sp?) - on here who might be able to give you some pointers. The gentleman's username on here is "trevoratxtal" and if I recall correctly he mentioned, in a thread when we were discussing NASCOM machines that he was involved (as the designer?) of systems in the 1970s and 1980s.

Dave

Offline DavidA

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Re: Legacy Technology RAM Boards - A Question for UK Modders.
« Reply #3 on: January 15, 2016, 06:24:58 AM »
You could also try asking on the Geekstogo website. I have always found them very helpful.

www.geekstogo.com

Dave.