Sinclair ZX80 / ZX81 / Z88 Forums

The modulator can be the cause of some video picture distortion.

I can't really tell from the photo you posted.

Mark

So to the age old question: is PRINT one character (as stored internally), or five...

Mark

Doesn't the hot running ULA burn your skin

Or are you using the issue 4 design

Mark

Yes, as I said, the principles are exactly the same: cut and remove LK1 and replace with LK2, cut the tracks to isolate the relevant pins (1, 2 & 23) of the 28 pin socket, add wires to restore the path of signals that go elsewhere on the board, add wires to feed the extra address lines to pins 1, 2 ...

Answered in a new thread here

Mark

Opps, you have asked me about this somewhere before

Yes, RetroTechie's site shows how to do the mod on an issue 3 PCB. See the archived web page here. All the same principles apply. The only real difference is the different layout of the issue 3 board.

Mark

its usually when saving you dont want to have both leads connected? never known of a cassette recorder to take input on its mic socket when playing, but some certainly feed the mic input back out the ear socket when recording..?? Yep, that's the main reason, but if you do have loading problems, it'...

It's the custom logic chip that "receives" the input from the Ear socket. When "LOADing" don't have the "Mic" lead connected. As with some tape decks this can cause an audio feedback path :(. Turn the volume on the tape deck to somewhere between 3/4 and maximum. Remember, the audio signal from the t...

Try to match the diameter of the thread as well as the pitch between threads.

Otherwise you risk damage to the plastic posts into which they screw.

Mark

Nice

Mark