Sinclair ZX80 / ZX81 / Z88 Forums

In the spirit of quick checks I have plugged in my ChromaSCART. With the onboard RAM switched off I get the display issue. With the onboard RAM switched on I still get the display issue. I was expecting it to work properly with the RAM on as this is in effect the same situation as having a RAM pack ...

I recall, along time ago, that I had a similar problem and replacing the voltage regulator fixed the problem. I got this idea from a forum posting but I can't find it. Not being a hardware guy I have no idea why the voltage regulator would garble the display, but replacing it worked for me. Regards...

It arrived like this yesterday. Sold as untested (as usual).

I haven’t had time to get technical yet - just a few minutes to try some high level stuff at lunch time.

Hopefully when the kids are in bed…

Don't forget, with 16K bytes of RAM, you get a fully expanded display file, and it can be in a different position in RAM. Have you tried changing the ULA? Mark I will be looking for a spare later on thanks. If I type in a program that takes up most of the 1K and it doesn’t corrupt would that prove ...

I will check inside the keyboard sockets just in case but it does the same with just the Memotech keyboard connected.

It loads and plays the games that I have tried. Although the screen is suitably garbled.

This is what I get when I type all of the keys:

The fact that it also works with a 16K ram pack but not without would point to the RAM being faulty somehow but replacing it made no difference.

I got a zeddy and it does this: https://www.sinclairzxworld.com/viewtopic.php?p=54578#p54578 When you type using either the built in keyboard or my Memotech keyboard it does not show all of the characters you are typing correctly. If I connect a Spand or a 16K memopak after a very short while it wor...

With a Spand plugged in:

I think it may have belonged to this guy?

https://youtu.be/YjpcZPT1-NA?si=gkNBGdly1rDrau8Q