Sinclair ZX80 / ZX81 / Z88 Forums

Hi, I have a ZX Printer with 1 broken stylus, so i need spare parts on this one.
It seems these were more then just a bended piece of steel.


See the following pictures:

Hi, I can't read what is printed on the EPROM, but if it's a 2764, then the pin-out changes from 2364 ROM and the wires must correct this. Peter It says 64K ZX81 And some Texas Instrumends code. So its an official 8 K rom However it seems to be an Eprom as there is a sticker on its window. The wiri...

Anyone have an idea what this ROM mod does?

How many 'Issued' boards were manufactured in the life of the ZX81? I have only seen 'ISSUE1'and 'ISSUE3' I don't really know what my first one was (about 26 years ago?) I don't really know what i did with it, probably gave it away, good ol me heheh. I moved to APPLE][ after that (via a BBC/ACORN) B...

Yo, there was similar topic made by me, some time ago. I've got 2 machines too. Both has the same feature. Therefore I know it is a typical feature of ZX81's contruction. A very low level of MIC output. Which is most annoying as musical demos also use this connector (grrrrrr). I will perform additi...

Hi. I had 2 ZX81's that both had very very low output signal. Hardly noticeable and probably leakage as the little signal disapears when i disconnect the UHF out. I get the stripes as usual during save. I see on diagram c12 47 Pf (pico) and c11 47 Nf (nano) Both caps are ok. Could it be a typo and s...