Sinclair Computers
Exhibit: Sinclair Computers

Clive Sinclair's ZX81
From Planet Sinclair

... the awfully badly designed Sinclair Ram-Packs

You slotted them onto a bare piece of circuitboard at the back of the ZX-81 and then you prayed that it didn't wobble too much, because if it did it usually shorted out (I managed to that 3 times ). This lead to the local store getting fed-up with replacing Ram-packs on guarantee and eventually asking me I would like to upgrade to a Spectrum ( a very real and heavy 'Puter at that time)

Thanks to GREMLIN