In this repository you find some addons which I created for the Sinclair ZX Spectrum computer
This is for personal use only. You may not sell this design without contacting me.
The Sinclair Spectrum was the first Sinclair computer which offers color. Besides that the biggest new feature comparing Sinclair's first computers ZX80 and ZX81 was the hardware video generation. The ZX80 and ZX81 have to generate the video signal by software which eats up most of the CPU time. On the ZX Spectrum this was done by the hardware itself. So the CPU can run user programs at full speed. No Slow and Fast mode necessary.
There were several versions out there. The first one was the small "rubber keyboard" version. Very small, but only with a rubber keyboard. Then there where several versions with a keyboard with "real" buttons. But these were also only some real keycaps pressing on a keyboard foil. Better typing as on the rubber version, but not comparable to a keyboard with real switches.
The first addon I created was a keyboard PCB with real cherry switches. See the SpectrumPlusKeyboard directory.