Sinclair ZX80 / ZX81 / Z88 Forums

The non-booting beige zeddy just needed a new Z80. Much better (cheaper) than needing a new ULA!

Lardo Boffin wrote: ↑Tue Aug 01, 2023 9:35 pm The zeddy in the full box is a slightly unusual issue one:

I don’t remember having a USA zeddy like this before (although probably have all things considered…)

It has a UK/European UHF Channel 36 modulator, R30 is not fitted, it looks like it has a 1K Byte SRAM chip. Maybe Sinclair were short of normal UK boards and instead used a board intended for the USA market?

Mark

Moggy wrote: ↑Tue Aug 01, 2023 10:07 pm I've edited my post to say that I think it's a Sinclair board made for the US and not a Timex one and has been butchered for UK use.

BEWARE: If its the Republician version ROM on startup it will check the 1k RAM to 1024 and demand a recount

Or the bi-partisan ROM that cannot decide whether it should boot up or not.

A nice working issue three.

Issue three with a spiral bound manual rather than the normal spine type that usually accompanied the issue threes.
Also there is something endearing about those old Bakelite type 13amp plugs that takes you back a bit.

If the unworn ZX81 logo is anything to go by this should be a quite unused specimen. Please give us some internal shots Lardo as you progress with it.

Sorry Moggy. Never opened that one.

An issue one, three and postal box. Also cables etc. but they are elsewhere at the mo.

Both work fine but the issue three has a few dead keys.


The issue three’s keyboard was beyond redemption so I opened it up to replace it:

And I thought you were going to say that the box was unresponsive…

Mark

I’d be worried if it wasn’t!

A slightly ropy (no feet or case screws) non-working issue one:


The PSU seems ok though.

Edit - both the ULA and Z80 were dead in this one.