Amiga 500: Part 1 - My first retrocomputer
While I’ve never been much of a collector myself, over the last couple years I’ve acquired a taste for retrocomputing content, avidly consuming the videos produced by people like The 8-Bit Guy, Adrian’s Digital Basement and Jan Beta, among others.
I’m amazed by the love they put on testing and restoring all kinds of old computers, and it’s definitely contagious. So, some months ago I decided to go shopping myself.
Choosing the right retrocomputer for me
It’s pretty common hearing stories of people choosing their retrocomputers based on their child memories of the systems. In my case, the first computer we had at home was already a 386 PC, so that didn’t work for me.
Instead, I choose one based on the system’s architecture and the current status of its retro-scene. And, with that criteria in mind, there’s an undisputed king: the Commodore Amiga.
Not only has a very interesting combination of a Motorola 68K with custom chips coupled with a surprisingly advanced OS, but in 2025 there are still people producing hardware expansions, accelerators and new software.
There are various models to choose from, but being the first one I was buying, I opted to look for an Amiga 500, which is both cheaper and easier to find.
Finding a deal
Over the last 10-15 years, most retro stuff went from being sold almost for free on garage sales, to becoming pretty much luxury products. I basically had two options, play it safe and pay extra (north of 300 euros) for a tested Amiga 500, or risk it a bit with an sold-as-is system, which can be found cheaper. And, motivated by videos like this one were Adrian fixes a field found A500, I decided to go with the latter.
After 2-3 months of looking through various second-hand sites, I finally found one offer with a reasonable price (160 euros) for a system which the seller claimed the only thing they knew is that “the floppy drive makes some noises after powering it up”. As this would be an indicator that the system is, at least, running some code from ROM (Kickstart), I decided it was a reasonable risk.
The first surprise
The system arrived home a week after closing the deal. And with it, the first surprise. Let’s take a look at the photo from the seller (top), and the one I took of the actual system (bottom):
The keyboard layout can’t lie, what I have is definitely not the system in the seller’s photo. Most likely, the seller had multiple systems to be sold and reused the same photos (which is not okay for second-hand products). I don’t really care about the layout (I actually prefer the one I got) but I no longer know if the “floppy drive makes some noises after powering up” applies to this system or not.
In any case, trying to file a complain is going to be a long and boring process, and well, I do have an Amiga 500 system here, so let’s do something with it.
Disassembly and visual inspection
First things first, let’s start by checking the internals for any obvious problems, like corrosion or leaking capacitors.
The RF shield is rusty, but that shouldn’t be a problem unless the rust has made into the board. Fixing the shield would require sanding the rust and giving it a coating of anti-corrosion paint. Since the Amiga 500 can work with it, I’m leaving that as a future project.
The system comes with a trapdoor RAM expansion board. I couldn’t find any references about it anywhere, but the chips are 256K each, so this must be expanding the system with 1MB of “Slow RAM”. It doesn’t come with an RTC clock, which is nice because the battery can’t leak (because there isn’t one), a very common cause of corrosion on retrocomputers. I was planning on buying a 512K memory expansion with an RTC to pair it up with a Terrible Fire accelerator in the future, but this one can come handy until then.
The board is dusty but doesn’t have any evident issues (no corrosion, no leaking caps, etc…). It’s a Rev6 board with an Agnus 8372A, which is pretty good news because that means it should be possible to turn Slow RAM installed in the trapdoor expansion into Chip RAM with a relatively simple mod on the board, expanding the latter from 512K up to 1MB (which should be enough for running the vast majority of games, both oldies and newly produced).
Cleaning it up
It’s now time for a good clean up of both the internals and the exterior. For the latter I’ll be just using hot water and soap. I might consider doing some retrobrighting in the future, more as a learning exercise than something I feel this machine really need it.
The board looks even better after doing a first pass with some anti-static brushes.
The mouse internals look really good, with no debris on the cilinders. Someone must have cleaned them up before storing it years ago.
And on the outside it looks pretty good after the hot water plus soap treatment.
The hardest part (or, at least, the one involving more labor) is cleaning up the keyboard, which requires the removal of every key cap, the metal plate and the membrane
One of the corners of the metal plate was a bit rusty, but luckily there weren’t any traces of rust on the inside.
A gentle brush with a fiber optic pencil did wonders on it.
There’s a half-broken trace in one corner of the membrane, but the trace tested positive for continuity, so I’m leaving it as it for the moment. I wonder if it has been like that since the day it was produced in the factory, ~35 years ago.
But, does it work?
Well, I don’t know. I’ve preferred to err in the side of caution and measure the voltages on the power supply’s output before plugging it to the board, and turns out the -12V rail is way, way off, with my multimeter showing a voltage somewhere around -2.45V.
While the -12V rail is, AFAIK, only used for the low-pass audio filter and the serial port, this clearly points to the power supply being faulty, so I don’t want to take any risks.
I want to eventually fix this power supply (mostly as a learning excercise), but not now. Trying to do so without a reference working system is the perfect setup for all kinds of frustration. So I’ve simply ordered a brand new power supply which will get here in a couple days. But, of course, this means the first real test of my first retrocomputer needs to wait until then.
To be continued…