Amstrad CPC 464

The Amstrad CPC 464 was the third computer I owned and even though Amstrad had a reputation for cheap and lower quality HiFi systems, the Amstrad CPC 464 was a great machine. Maybe it helped that it was compared to the Sinclair which were famous for their cheap build quality. The main thing with these machines though was the price. They were cheap and that meant I could afford one.

I had been looking for a while for one in South Africa but they are not so common here so when Gary Petzer from the Vintage Computing and Console Group of South Africa had one for sale I jumped. I didn't expect much as I knew it wasn't in working condition but I thought I could fix it.

When it arrived it didn't look too bad from the outside but then things turned!

I soon realised that one of the previous owners must have left it in a swamp for a good part of it's life. I was still thinking there is hope as I've seen videos online with machines which looked worse than this and they worked again.

The keyboard membrane was the worst but I cleaned it up and it actually worked partially. I realised though that it was never going to be great so posted on the Amstrad Facebook page and manged to pick up a new keyboard and ULA. I will get to the ULA later but I found out that it was fried also. I suspect some sort of sugary drink was poured over this machine which is not great for electrical devices.

The new keyboard and ULA arrived.

After a clean of the PCB I started testing. I went through multiple iterations of tests and realised that this machine had suffered from multiple chip failure. Not only was the ULA fried, many of the RAM chips were fried also. I built a little tester using an Arduino and checked each chip.

Four of the 8 RAM chips were faulty, along with the ULA, two 74HC153s, a 74HC373, the 6845 and Z80. The AY-3-8912 was also not working but that was due to the legs rusting off. 

The AY-3-8912s are not easy or cheap to replace so I soldered (very badly) a new leg on to it and luckily it worked. 

This restore took quite a while as I had to wait for parts in between, but eventually I replaced all the faulty chips and added sockets for good measure. I also added a heat sink on the ULA, but I'm thinking I need to get a better and bigger one but this will do for now with limited use.

The end result though was a working Amstrad CPC 464 and I could relive my youth with yet another of my childhood machines. You may notice the DDI-4 attached. I ordered this while fixing the machine. It is very cool and adds the ability to use a GOTEK drive in addition to the PARADOS ROM.

And here are some pictures of some classic Amstrad games loaded using the GOTEK and DDI-4.

I didn't mention at the start but this is actually a later generation Amstrad CPC 464 and not exactly like the one I owned. Luckily though on a recent trip to Scotland, I picked up another CPC 464 which is a first generation machine. You can see the difference in keys in the two pictures below. I also got a new AY-3-8912 as my fix will not last.

Now I need to find an Amstrad CPC 6128 which was my 4th machine. I traded my 464 in for it after it stopped working and shop gave me the full price back on my 464 as a trade in.