Some random sinclair ZX80 stuff
Way back in the mists of time, as fresh faced thirteen year old, I got to use a borrowed ZX80 at home. I spent a lot of time learning Z80 machine code, as there was only so much you could do in 1K (or even 4K, once it acquired a ram pack!)
A year later, I got bought the ZX81 kit, which I built, and had just a much fun on, along with loads of peripherals, interface cards, custom-character upgrades. new keyboard... etc.
Then I encountered a BBC Micro, and that was pretty much that... sold all the sinclair kit, and got myself a Beeb...
Anyway, perusing some old paperwork, this fell out. It's component information and circuit diagram for a "video upgrade" for the ZX80 (And Microace) which based on the wording "flicker free fun" would seem to be a "slow mode" upgrade...
Anyway, here it is for your perusal. Maybe it would be of interest to somebody!
Compshop Video Upgrade(pdf)