... or , gee that is a tiny computer
Poor joke time:
If I remember correctly, it was on RetroKomp/LoadError 2014 where Bachoo brought his Sinclair machines collection. I was kinda amazed how tiny ZX81 machine is.
Obviously, I needed one for my own collection ;P
Several CLICKS later it was on a way to my place.
I was like .... WHERE IS IT !?
After a week, I've finally received it.
I was super happy that I've received my lil machine and I've happily started to set it up. Unfortunately, after a while of fiddling with it, I've figured that PSU is kinda dead :/
Dissasembly followed shortly ...
Here are all the chips and PCB overview after opening it.
I've noticed that there might be a slight problem with oxidized keyboard membrane connector.
That required a bit of gentle work with sandpaper.
Also, a second strip of the connector was cut a bit and strengthened with a bit of thick PVC foil and Kapton" tape.
Once I've sorted out simple problems, I was ready to connect my little precious computer ... and ... F>A>I>L
I wasn't able to tune my TV to the proper frequency. By proper, I mean ANY visible video output.
A bit of internetz lurking gave me a solution - composite mod ;)
At first, I thought it will be as simple as in 48k, which is an easy thing to do and requires rewiring few elements and that's it.
That was not a case here, but still nothing really fancy.
All I needed to do is to add an amplifying transistor circuit to a video signal along with a grounding resistor (schematics are popular on internetz :)
That was enough to get a decent video output on a modern TV
I've put it all inside an original modulator case.