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Plus/4 Repurpose


Retro Me

My younger self

Back in time

They say first experiences stay with you. Well, as a 10 year old with a brand new Commodore Plus/4 I can say that this is true. It is not uncommon for me still, 35 years later to get the old Plus/4 out and have a game of Treasure island or Icicle works. My kids even enjoy having a go on the old comp.
Now, over the years I have owned rather a lot of retro computing equipment, most of which I sold a few years back, however, I couldn't let go of my Plus/4 and an empty +/4 case and keyboard. For years, this empty keyboard has sat under my bed, awaiting some kind of love.
This is what I did....

On-Line Teaching

Using the Plus/4 in a modern environment

After a weekend of sometimes frustrating soldering, I now have a Commodore Plus/4 USB Keybord. I can't deny there was a certain hygge feel to doing my registers on a 36 year old keyboard. Anyone who owned a Plus/4 will remember that lovely spongy feel and the clacky sound of its keypresses.
I used this for about 4 hours, and then.... gave up!
Truth is, some of the characters are in the incorrect places, things like brackets() and {} and [].
This might not pose a problem to some, but when I was trying to live demo some python coding, it really held me back. I eventually unplugged it and sat it on a shelf.

How did I make it into a USB compatible keyboard?

Glimpse image processor

Initially, I stripped the keyboard and gave it a good clean with methylated spirits on all of the contact areas.
I had a Keyrah v2.0 hanging around which I used to have in my retro CommoPi 64.(I'm going to have it's original motherboard fixed).

broken ribbon cable

Finding instructions for the Plus/4 was almost impossible, however, I found Mr Ian Hill's blog at ianwilliamhill.co.uk
I then ignored his description of the madness that is trying to solder the Plus/4's keyboard ribon cable to the keyrah.
2 hours later, I decided Mr Hill is wiser than I.

Ribon cables soldered to plus 4 keyboard circuit board

I put an order in for these Breadboard jumper cables
Armed with my new set of Jumper cables, I wet to work de-soldering the old ribbon cable and soldering in the new wires. This went well..... until I tried connecting them to the Keyrah. Very soon they started to snap at the solder points as soon as I bent them over:-( WAHHH!

Inkscape vector graphics

Obviously, I needed to have a cup of coffee and a biscuit!
Once recharging my optimism, I went back to it.

Nicely attached ribbon cable

This time I left the connectors on the jumper cables. I bent them over before I soldered them in. Why I didn't do it this way the first time I don't know. It went swimmingly!
I did connect the other end to the keyrah the wrong way, but eventually got it right.

Keyrah in place

I then proceeded to drill 2 small holes through the bottom casing and used some bolts and spacers to attach the Keyrah to the casing. I used a grinder to flat the bottom of the bolts as much as possible to avoid scratched tables.

Rear of Plus/4 with keyrah fitting in nicely.

As you can see, it fits incredibly well into the existing user port without any modification.

Finished artical. USB Plus 4 keyboard

The lovely USB compatible Plus/4.

Since this page was made, I have further worked on the Plus/4 and turned it into a commodore emulating computer. It has a raspberry pi inside and boots up into either Plus/4 mode or C64 mode. I will go into this another time.