Time to try my luck on another ZX Spectrum repair, this time a ZX Spectrum 48K with an issue 3b motherboard.
The RF module has already been modified to output a composite signal, so it was easy to connect it to a TV set.
When I fixed the ZX Spectrum 128 +2B machine I simply replaced the non-working keyboard with a known to be working keyboard. If should be fairly straightforward to get this keyboard working again.
On eBay I bought a set of four untested (which usually means broken) joystick interfaces for the ZX Spectrum, based on the pictures provided they all looked fine. Although one seemed to be missing the keyway peg at pin 3.
The set consisted of the following interfaces
Several months ago I had won an auction for a ZX Spectrum 128 +2B of an unknown state and no big surprise the machine was not working properly. This is what I saw after booting up the machine
Black screen with a white border
On August 5th, 2018 Uwe Geiken posted a programming excercise in the Facebook group ‘BASIC on the ZX Spectrum’. The challenge had to do with something called the “Kaprekar’s Constant”. I had never heard of it before this post appeared in the group. Never too old to learn something new…
The post linked to a Wikipedia article about the Kaprekar’s Constant. The article lists the following properties for the constant (6174);
