Of Bees and PETs

I can see the Matrix!

Another quickish update on two of my systems.


Home made “everything” cable. Video out, Power in, Audio Data in and out.

The Microbee is happily working now. I swapped out an underpowered PSU for a more “meaty” one and now it’s booting reliably and is able to load games off my nearby Android phone. I just use the built in Android playback app to playback WAV recordings of Microbee software. I successfully played a range of games including Frogger.

To get Frogger to work, I had to build a joystick adapter, I built one according to the instructions in the Microbee Engineering Notebook. (Page 10)

A couple of diodes as a resistor array and that’s basically it. I used an offcut of “experimenter board” to solder on to.

This is a simple resistor array. across some inputs, so was a nice easy afternoon project. The original design suggested cutting the end off an Atari compatible joystick. Instead I just added a DE-9 socket so I could switch and change which joystick I wanted to use. It was a cheap and easy upgrade and I am happy with the way it looks!

This is neat AND tidy. Not like me at all.

Commodore PET 4032

This one scared me a lot. The age of the equipment. The integrated CRT. The power supply being integrated with the motherboard. So much to go wrong! I spend the week cleaning and cleaning and cleaning and cleaning the board. I initially brushed it with antistatic brushes to get most of the dust off it. (About a tablespoon of dust and a dust bunny of fluff the size of a golfball).

That’s disturbing.

I then attacked it with isopropyl alcohol and a toothbrush. That got more of it off, but I ended up having to use distilled water on a brush, followed by isopropyl, followed by a cloth to wipe up what was left. It’s still got a thin residue of caked on dust on it.

This is after all the scrubbing…

After that I checked the rectifier diodes (OK) and then checked the voltages out of the transformer.

The only hit I can find for that transformer is another PET owner trying to diagnose one.

They looked OK so it was time to turn it on and…

Snow Crash

Well that’s better than I expected to be brutally honest. There’s a cursor visible in there, and I was able to type in a “program” and see some of the garbled characters changing.

At this point I’m suspecting either a corrupt character ROM or bad Video RAM. Not sure which. More investigation will be required.





2 responses to “Of Bees and PETs”

  1. […] the Microbee computers, I’d managed to make the cable for the Microbees, and proven the base 32k “Communicator” model was working fine. I’d resurrected the PC85 and upgraded it to an 85b model complete with a bunch of embedded […]

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