These are proper machines, Thinkpads are still about the best “normal” laptops imo if you just want to work and have something you can rely on.
I’ve had a little saga with a fairly recent acquisition, something some people would probably refer to as being from the British Leyland of computers - an Acorn A7000+.
Brief (ha) bit of history - Acorn Computers may no longer be with us, but what they left behind was hugely important for reasons I’ll go into later.
This machine was Acorn’s last attempt at going after the home market, and ran alongside the workstation Risc PC up until Acorn’s demise. While they were never a huge seller as by this point Windows PCs were taking off, these machines were hugely popular in schools, as Acorn had produced the BBC Micro years earlier for the BBC’s computer literacy project in schools. Due to that partnership, those Micros would later go on to be replaced by the Archimedes line which was what I grew up on, Acorn A3000s/A3020s, and to a smaller extent the A7000s seen here. In our school only the teachers had A7000s and in very small numbers, as the Computers for Schools project was beginning to move to Windows based machines by the mid to late 90s.
I had been aiming for a Risc PC for a while but prices are on the rise, this A7000 came up with a fairly low starting bid on Ebay and I chucked a low bid onto it on a lunchbreak expecting it to rise later on. 9 days later I woke to a notification telling me I’d won it. At this point I decided I should probably look at the pictures properly on a bigger screen than my phone and noticed potentially why it had remained so cheap - the on board CMOS battery had leaked and the top corner of the motherboard was rather covered in green fur and acid damaged. There was only a very blurry photo so the damage wasn’t too clear. I was tempted to try and cancel the sale, but decided to go for it anyway as if it didn’t work, it’d make a cool PC case right?
Specs of this are as follows:
48mhz ARM7500FE SoC (Yes, that ARM, again I’ll come back to that later)
8MB of soldered on board RAM
RISC OS 3.71
4x Sony CD-ROM
840MB Conner Hard Disk
When it arrived at my underground PC repair lair, it had obviously been apart as it was a bit cleaner than the blurry picture I’d seen, the drive cage was lose and had been pushed out of place and was resting on the board. Despite the cleaning attempts, the damage was still obvious and wasn’t pretty.
The big SMC chip in the middle there had green pins down the side nearest the battery, and the acid damage had worked along the tracks along into the serial ICs, IDE circuitry, real time clock, it didn’t look good. So, I got myself a toothbrush, swabs, some vinegar and some IPA, and got scrubbing.
This picture was during cleaning - it didn’t get a lot better than this to be honest by the time I was done, this is mostly damaged solder mask now.
At this point I decided to give it a bash and see where I managed to get to, knowing that I’d be missing at the very least the CMOS/RTC circuits (I didn’t know about IDE damage at this point).
An important point to make here is that Acorns had the base OS in ROM, at least enough to boot to a basic desktop or from a disk. Because of the soldered on RAM and socketed ROM chips, you can run it in a bit of a frankenstein state to check that it will at least boot.
First boot saw nothing other than a green light. This was kind of expected as I knew it wouldn’t know where it was due to the lack of CMOS anything. Upon doing a reset on boot attempt two, I heard a noise I hadn’t heard for the best part of 20 years. Acorn’s make a beep when they pass POST similar to a PC, but rather than the harsh BEEEP you get from a PC, they make this very soft, recognisable sort of “foop” noise. You can hear it briefly here at about 10 seconds:
I just about teared up as childhood computing memories came flooding back 
, but sadly I had no output on the Samsung TV I was trying to use. I knew my main PC monitor supported a few old weird modes so went and grabbed that, and lo and sodding behold:
After sitting here for a good while, I was greeted with a disk error which was expected due to the lack of disks, and then joy of joys, an actual desktop:
At this point I tried reconnecting the hard drive which I’d checked was alright, but the machine still wasn’t seeing it. A user was having a similar problem on an Acorn forum and provided the route of some traces which were damaged on my machine, so I started there. I was very nervous at this point, as I’d never soldered SMD anything before, and I knew pads and stuff had already been attacked by acid. My first attempt at jumper leads were not particularly neat, and I added a battery holder to replace the CMOS battery I had removed earlier.
Mid first repair:
Getting this back together did show progress, the machine was now seeing the hard disk, but would fail with an error immediately upon trying to access it:
At this point I was pretty lost and it was getting near the end of my knowledge. This had managed to get the floppy drive working and my battery was now keeping the CMOS settings, but my IDE was still almost completely dead. I started looking into replacement motherboards, but prices are mental relative to the value of a working machine. As the little bugger appeared to actually be trying, and I couldn’t really make it any worse, I decided to perservere and learn. I spent a few hours with my multimeter tracing this beautiful diagram across the section of the board where the IDE circuitry lay.
All roads lead back to the big SMC controller chip in the middle in the pictures above. After a few hours, I managed to find one trace on the underside of the board that while looking relatively undamaged, was showing high resistance. I put a jumper across it as I couldn’t find anything else, tidied up my previous jumpers as they were too long, and fired it up for one last attempt.
I have never been so damn happy to hear the clicking and whirring of an ancient 90s hard drive.
This also meant the CD drive was now working, so it felt appropriate to play a certain piece of 90s inspired musical beauty:
I was cheating a bit here using a WAV, but it will just play a 128kbps MP3, with the CPU absolutely pegged at max usage.
At this point, after tidying my repairs, I had the machine working completely and absolutely perfectly. Got a few games going just to check it was all OK, and managed to bag myself an ethernet card off Ebay that I haven’t managed to get going yet. As luck would have it, a work colleague is into old computers as well, and had a copy of the full Acorn internet suite with drivers for the card I got on a CD from the era, but no machine to use them on, so lent them to me in the hope I can get it online. Further things to come from this one I think.
Now if you’re still reading, 1) you must have very little going on, 2) you may be thinking “You still haven’t told me why Acorn is so important you prune.”
Well, in a sort of rough abrdiged version, after the BBC Micro, Acorn wanted to move onwards from the 6502 CPU and created something called the Acorn RISC Machine, or ARM, CPU. Their aim was efficiency rather than outright power, so cheaper production costs, lower power requirements, and lower heat output. The perfect example of this can be seen in the A7000 - here was a machine that could compete with mainstream PCs of the team but had extremely lower power requirements and was completely fanless in it’s standard spec.
The first ARM was an addon to the BBC Micro as a coprocessor, while the second version of this architecture went on to power the first few of the Archimedes line of computers and was a relative success, less so as home machines and more as education tools. In 1990, Acorn moved the ARM section of it’s business to a seperate company and renamed it Advanced RISC Machines Ltd, which would later on become the ARM Ltd that exists today and escape the demise of Acorn Computer.
In the late 80s, a company you might have heard of called Apple Computer formed a sort of partnership with Acorn to develop a new version of the architecture which would go on to be used in the Newton PDA. The Newton might not have been a success, but that sort of application proved to almost be a vision of the future, as while ARMs usage became less suited to use in desktop machines it’s low power use and low thermal output meant it took over the world of mobile processors. Phones, Tablets, Cameras, Games Consoles, Routers, Media Players, even watches now all (mostly) use CPUs based on the ARM architecture, making it the most used CPU architecture in the world by quite some margin.
Before anyone fact checks, there might be some tiny errors in that last bit but I was (honestly) trying to keep it a bit short.
