In preparation of assembling a TZXDuino (compact) I need to be able to program an Atmel ATmega328P micro-controller.

I have a bunch of Raspberry Pi’3 lying around doing nothing and it would be nice to be able to use one of these Raspberry Pi’s as a programmer unit. After some research there are plenty of tutorials available on how to program an ATmega328P micro-controller (and a couple of other micro-controllers) using a Raspberry Pi.

When I was fixing my ZX Spectrum +2B I could not test the joystick ports since I don’t own any Sinclair joysticks. To be able to use joysticks that use the Kempston (Atari compatible) standard I would have to make use of some sort of adapter to convert one into the other.

There is enough information available on both types of joysticks, so it is not hard to figure out how the pins need to be rewired (See table below). Since the Sinclair joysticks do not support auto-fire or additional fire-buttons only 6 pins (4 directions, 1 fire and ) need to be rewired.

To downsize the images used in my post I make use of the services provided by TinyPNG. Up to now I usually follow the following steps to make and prepare the images for a blog post

On iOS device:

After my post ‘ZX Spectrum 48K (Issue 3B) with video issues (Part 1)’ I spent some time researching the issue and done some testing on the motherboard

• Schematics and layout for the Issue 3B Motherboard
• Found information on the ‘weird’ modification
• Measured voltages on the ULA, CPU, ROM and lower RAM chips
• Measured temperatures for the ULA, CPU, ROM, lower RAM chips (IC6-IC13) and upper RAM chips (IC15-IC22)

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.

Cleaning the parts

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