ZX81 on a Spectrum PSU

[daveyj67]

Hi all

I gather that it's possible to use a ZX81 with a Spectrum PSU using a conversion cable. Does anyone know where I could get one, or how easy it would be to make my own?

Thanks

Dave

[Lardo Boffin]

Never been much for making cables - I got one from Retroleum (https://www.retroleum.co.uk/). I don’t think he has had many for sale recently though.

I bundle these with zeddies I sell:

https://www.ebay.co.uk/itm/391143177666 ... media=COPY

[1024MAK]

Yes, you can use a ZX Spectrum 9V PSU.

I don’t know if anyone makes them.

Lardo, I looked on the Retroleum shop, but couldn’t see them.

You need:

• a mono 3.5mm jack plug,
• a 2.1mm/5.5mm barrel inline socket
• a length of two core cable (figure 8 type or round type, but make sure it fits in the connectors)

Or you can modify one of the power switch cables that Retroleum sells.

The inner of the 2.1mm/5.5mm barrel connector is negative (-), this should be wired to the sleeve on the 3.5mm jack plug.
The outer of the 2.1mm/5.5mm barrel connector is positive (+), this should be wired to the tip on the 3.5mm jack plug.

Do test the polarity of the 3.5mm plug before connecting it to a ZX81. The tip should be positive (+). Keep in mind that the voltage from any of the Sinclair 9V PSU will be higher than 9V. Typically a UK1400 PSU will be between 11V and 13V off load.

Mark

[daveyj67]

Thanks for the info. I'll order the parts and make one up myself.

Dave