Sinclair ZX80 / ZX81 / Z88 Forums

Another member has reported a similar problem here.

Mark

Good plated works best if both the plug and the socket are both gold plated. If there are different metals, even if one is gold, if there is any dampness or moisture, then there will be a reaction between the different metals... [Although if used in a nice dry warm place, this should not be an issue...

blittled wrote: ↑Fri Jan 08, 2021 1:58 pm I didn't notice the DB9 connector until I looked at the recent picture. Is that a standard RS232 port?

It’s a joystick port.

Mark

So pictures of people adding a small heatsink to the ULA is, be polite, "stupid". OK, lets skip that one, makes it more easy... Err, if you search the forum you will see that this subject gets talked about a lot. And obviously opinion varies. Some are in the camp that fitting a heatsink may help ex...

Link to the listing for Pokemon’s ZX8-CCB (ignore that this listing is for the ZX80, this module works for both the ZX80 and the ZX81, Pokemon normally has a listing for each computer when he has some modules available). See also this topic about the changes as a result of BREXIT. I do recommend Po...

I should add that the ZX Spectrum 128K (toastrack) consumes about 960mA if there are no expansions fitted. This is under the 1.4A maximum that a UK1400 PSU is rated for. So although not recommended, it is possible to use a UK1400 to power a ZX Spectrum 128K. You just have to be very careful if you i...

Sinclair ZX Spectrum Power Supply Specifications ZX Spectrum 16K / 48K / +, UK1400: * Input: 240V AC, 50Hz 0.11A * Output: 9V (nominal) DC 1.4A * Output polarity: outside is positive (+), inside is negative (-)(inner diameter is 2.1mm) ZX Spectrum 128K: * Input: 240V AC, 50Hz * Output: 9V (nominal)...

But I thought that ULA mainly fails because gets too hot? The design of the ULA is such that it is intended to run hot. This is 1980s technology. Very low power chips came along later... And for some reason, people think that if it’s too hot to touch, something must be wrong. Yet they don’t do that...

I hate it when Moggy has the crystal ball on full power... (it’s all that fur rubbing against it generating a high voltage static field) :lol: So I really need to get composite out now. Ok if I do the simple bridge of the ULA output? At least I should see something... You need a buffer transistor am...

Yes, there is a specific PSU, but it will work for testing purposes with a UK1400 PSU as used with 48K/+ ZX Spectrum machines.

Watch this video.

Mark