Sinclair ZX80 / ZX81 / Z88 Forums

Hi All,

Searching for a diagnostic card. Whats the best out out there? I'm interested one that supports all zx models, and if possible some clones as well, as the portuguese timex 2048.

Thanks.

Not sure about the clones or the Timex 2048 or similar, as some Timex models use a different edge-connector pin-out compared to the ZX Spectrum.

Most of the diagnostic cards are copies or variants, of the original detailed on this web site.

However, a diagnostic ROM can be run from any expansion card that can either take a physical ROM (EPROM/EEPROM/flash ROM) chip, or any memory that can act like a ROM. And there are various different diagnostic ROMs available.

I’m not sure which one is best, because they all are slightly different, and how well they work depends on the actual fault.

The diagnostic cards that include LEDs can give you information if the screen is unreadable. But not all the diagnostic ROMs support driving the LEDs.

The original diagnostic ROM on the site I linked to earlier does support the LEDs, as does this much improved version

The other major modern diagnostic ROM is described here.

Mark

Thanks Mark,

I'll see if I can buy one from retroleum or bytedelight.

Thank you once again