ZX81/TS100 From Old to New: Part 1 (Intro & regulator replacement)
16I know I've done a few videos on these before but I thought it *might* be interesting to do one from start to finish.
So here's a Timex Sinclair 1000 (the US version of the Sinclair ZX81) going from unknown state (built in 1982) to modern 2022 state.
This first part is a quick comparison and then replacing the 7805 regulator with a modern one.
I already have a video about converting to composite video output but I'll do another ... better (??) ... one for this particular machine:
https://youtu.be/xafVu0n1VEY
Other parts to come: replacing the RAM, replacing the keyboard, replacing capacitors, maybe replacing the ULA.
Inventory of this machine:
[1] Board version is Issue 3
[2] ULA is 2C210E (datecode 8241), socketed
[3] Z80 is a genuine Zilog Z8400A (datecode 8233), socketed
[4] ROM is a D2364C (8KB, datecode 8242), socketed
[5] RAM is an NEC D4016D (2KB Static RAM), soldered
Modern voltage regulators - highly recommended - ask Daniel to leave the header pins off so you can mount it anyway you need:
https://www.ezsbc.com/
ZX81 ROMs:
https://k1.spdns.de/Vintage/Sinclair/80/Sinclair%20ZX81/ROMs/
ZX81 ULA versions:
https://www.bytedelight.com/?page_id=2678