Search found 51 matches

by RetroByte
Sat Sep 16, 2023 3:48 pm
Forum: Hardware
Topic: EPROM for 4K ZX80 ROM?
Replies: 18
Views: 5068

Re: EPROM for 4K ZX80 ROM?

I did receive some 2532A's and still had no luck programming them, until I found that they were really 2732A's :? at least I can make use of them.

The original 2532A's were faulty.
by RetroByte
Sat Sep 16, 2023 2:27 pm
Forum: WANTED
Topic: Looking for a ZX80 manual
Replies: 1
Views: 6172

Looking for a ZX80 manual

Looking for a ZX80 manual, maybe someone has a spare that they can sell for not too much money? :)

I'm in the UK.
by RetroByte
Sat Sep 16, 2023 11:34 am
Forum: Hardware
Topic: Easiest way to fit 2732 EPROM in ZX80?
Replies: 5
Views: 718

Re: Easiest way to fit 2732 EPROM in ZX80?

So far so good! :) Don't worry, I'm going to cover the UV window :) You can see from the photo I used a ST M2732A-3FI, that I bought from eBay. I flashed it with the cheap TL866CS that I've moded for an extra 5v input ,I'm not sure if it needed the extra power or not, I think the TL866CS can only ma...
by RetroByte
Fri Sep 15, 2023 9:33 pm
Forum: Hardware
Topic: Easiest way to fit 2732 EPROM in ZX80?
Replies: 5
Views: 718

Re: Easiest way to fit 2732 EPROM in ZX80?

Thanks Mark for the quick reply, I will try the same mod tomorrow :)
by RetroByte
Fri Sep 15, 2023 9:06 pm
Forum: Hardware
Topic: Easiest way to fit 2732 EPROM in ZX80?
Replies: 5
Views: 718

Easiest way to fit 2732 EPROM in ZX80?

Hello all again.

Without any extra adaptors, what's the easiest way to fit 2732 EPROM in ZX80?

It looks like pin 18 on the ZX needs connecting to 21 on the Eprom, but what do I need to do with the other two pins 20,21 on the ZX, 18,20 on the EPROM?

Thanks for looking ;)
by RetroByte
Sat Aug 12, 2023 4:52 pm
Forum: Hardware
Topic: USA ZX80 fitting zx8-ccb low video output voltage? Solved
Replies: 11
Views: 1297

Re: USA ZX80 fitting zx8-ccb low video output voltage?

There was a coil from the RF output to the metal RF case that stopped the ZX8-CCB working, so I've removed it.

I've mounted the ZX8-CCB in the RF box, which I don't normally do.

All the removed parts are bagged-up and will be kept with the machine.
by RetroByte
Fri Aug 11, 2023 5:35 pm
Forum: Hardware
Topic: USA ZX80 fitting zx8-ccb low video output voltage? Solved
Replies: 11
Views: 1297

Re: USA ZX80 fitting zx8-ccb low video output voltage?

I'M A COMPLETE STUPID IDIOT! :oops: When I first got this machine years ago, the RF box had been removed, after getting the machine working on my CRT, I soldered the RF box back on so I could fit the ZX8-CCB, but I didn't notice the insulation part missing, so it was shorting. I'm lucky it didn't do...
by RetroByte
Fri Aug 11, 2023 5:00 pm
Forum: Hardware
Topic: USA ZX80 fitting zx8-ccb low video output voltage? Solved
Replies: 11
Views: 1297

Re: USA ZX80 fitting zx8-ccb low video output voltage?

BTW, the third photo is just showing R36 that I have lifted one end.
by RetroByte
Fri Aug 11, 2023 4:58 pm
Forum: Hardware
Topic: USA ZX80 fitting zx8-ccb low video output voltage? Solved
Replies: 11
Views: 1297

Re: USA ZX80 fitting zx8-ccb low video output voltage?

Thanks for the reply, I had already started changing some of the components before seeing your reply, but luckily I did take a few pictures before. Have a look at one of the photos of the Mic jack, it has a short, which I thought would fix my problem, but it didn't. I think I have completely made th...