Some TS1000 use issue 3 ZX81 boards... the only differences are the RAM chip(s), the modulator and video circuitry, resistor R30, extra inductors (to reduce the RFI) and metal springs to make contact with the metallic layer on the inside of the case.Mustermann wrote: ↑Tue Mar 03, 2020 8:26 pm Let's start with the assumption that a Timex Sinclair 1000 is identical to a ZX81 except of the size of the RAM.
To upgrade to 16Kbytes, have a read of the links in this post
Mark