Sinclair ZX80 / ZX81 / Z88 Forums

Is it possible & relatively easy to change the power input on the ZX81 to use a Spectrum PSU?

Thanks,

Shaun

The ZX81 pcb isn't ready to take a different input.
So an adapter cable is the best way to get a spectrum psu to work with the ZX81.
Be aware the spectrum plug is quite common and in 99% it's polarity is inverted. So there is possible danger of destroying your ZX81.
A simple diode that is capable of 2A load should prevent this. Or a full rectifier. Then you can use spectrum and other 7-14V power sources without any harm for your Zeddy.
Kind regards Paul

Thanks Paul.

Is there a suitable replacement for a ZX81 power supply that I may purchase?

Regards,

Shaun

There are plenty.
E. G. https://www.amazon.de/gp/aw/d/B002TQ220 ... th=1&psc=1
Put it on 7,5V and plug in the 3.5mm Jack (TIP Is plus)
Kind regards Paul

I give advice on replacement power supply units here.

Mark

A power supply from an old Atari 2600 VCS game console has always worked well for my TS1000 (the US version of the ZX81). Careful if you buy a 3rd party supply. You'll want to have at least 700 mAmps and not all of the 3rd party ones supply that amount.