Thread: Zx81
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Old 1st May 2020, 11:43 am   #307
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 4,540
Default Re: Zx81

I have an idea that IC4 was a 1K*8 RAM (1K byte) possible a 4118. IC4a and IC4b were 1K*4 RAMs so you needed 2 for the 1K bytes. I think they were 2114 chips, a device that I regard as being 'change it if you get odd symptoms', the 2114 is possibly the most unreliable IC I've ever seen. A given board would have one or the other type of RAM, I think the pair of 2114s is a lot more common.
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