Sinclair ZX80 / ZX81 / Z88 Forums

Was it a Comcon Programmable Joystick Interface?

Mark

No problem. It's good that you have brought some Speccies back to life ☝

Mark

The manual is here

Mark

Correct

Mark

For a any of the new commands and functions and for existing commands and functions that have extra options, the ULA in the ZX Interface 1 pages in it's own 8K ROM.

Mark

IMG_20200531_092559_kindlephoto-1172251885.jpg IMG_20200531_092608_kindlephoto-1172312857.jpg IMG_20200531_092621_kindlephoto-1172389237.jpg IMG_20200531_092741_kindlephoto-1172552171.jpg IMG_20200531_092648_kindlephoto-1172447157.jpg And here are photos of a similar version from 1993. This design ...

I don't know much about this machine, but if you shorted pins on a power transistor or regulator and one pin was the unregulated input and the other pin was the regulated output (+5V for TTL computer logic supply), even a briefly, it causes an over-voltage on the regulated supply. Some chips when op...

Take some good quality photos from various angles before you disconnect or remove it.

Mark

If you have two RAM chips that are the same age and type and one is getting very hot, renew it.

If however it is just slightly warmer than the other one, it may be okay.

Mark

A microdrive head should look like a cassette tape head (as that is what it is).

Mark