Imagesource: https://youtu.be/6a8wxj9vJjU

The ZX81 is an extraordinary piece of contemporary history, that's for sure. Fortunately, enough units were produced, so that even today - 41 years after its introduction - you can still buy a used one, that should run for the next 40 years, given you give it a little refurbishment.

But can you completely rebuild a ZX81 with components available today? 🤔

Adam aka iNimbleSloth investigates this question and documents the result in his latest video.

The actual base project comes from Mahjongg. And the real challenge is the ULA chip - uncommitted logic array - which combines a number of functionalities, that would otherwise require a larger number of simpler ICs. To reproduce it nowadays you need ... a larger number of simpler ICs.

A quite interesting walk through.