I’ve been coveting this machine since it was born. Which was a few years after I was born, so imagine my delight when I acquired one that didn’t require me to remortgage my house!
So What the heck is a Sord CGL M5?
Good question!
Back in the early 1980s, absolutely everybody seemed to be making a home computer. Sinclair had the ZX Spectrum, Commodore had the VIC-20 and C64, Acorn had the BBC Micro and there were seemingly another 3,000 machines that nobody remembers.
And then there was this thing.
The Sord M5.
Sord was a Japanese computer company founded in 1970 by Takayoshi Shiina. The slightly odd name actually comes from SOftware haRDware, which is quite clever really.
By the early 1980s Sord had already been making business computers for years, but in 1982 they decided to have a crack at the rapidly growing home computer market.
And so the M5 was born.
Tiny Computer!
The M5 was released in Japan in 1982 and it’s a wonderfully tiny little thing.
Inside is a Zilog Z80 processor running at 3.58MHz, along with 16K of video RAM and…
…4K of normal RAM.
Yes. 4K.
My toaster probably has more memory than that.
But don’t let that rather pathetic sounding figure put you off, because the graphics hardware was actually pretty impressive for 1982.
It could display 16 colours at 256×192 and, more importantly, had hardware sprites — 32 of them!
It also had three sound channels plus a noise channel, making the M5 much more obviously suited to games than its tiny amount of RAM might suggest.
In fact, some of the hardware is remarkably similar to the MSX computers that would start appearing the following year.
Where’s BASIC?!
Here’s where things get slightly weird.
Most home computers of the period booted straight into BASIC.
Not the M5.
BASIC came on a cartridge.
There were actually three different versions available: BASIC-I, BASIC-G and BASIC-F, aimed at slightly different uses.
Which means that if, say, 44 years later some idiot buys an M5 without a BASIC cartridge, he has a slight problem.
Ahem.
Moving swiftly on…
The Sord CGL M5
The M5 was supposed to arrive in Britain towards the end of 1982, but suffered several delays before finally appearing properly in 1983.
And Britain in 1983 wasn’t exactly short of computers.
You could walk into a shop and choose from the ZX Spectrum, BBC Micro, Commodore 64, Dragon 32, Oric-1, Acorn Electron and probably seventeen other computers invented while you were standing there.
The M5 therefore had a bit of a fight on its hands.
Over here it eventually became the CGL M5, distributed by Computer Games Limited.
The UK machine also looks rather different from the Japanese Sord version. The original is a rather fetching dark grey and orange affair, whereas the CGL version is blue-grey and looks considerably more sensible.
Boooo.
But was it any good?
Actually… yes!
For games, the M5 was a surprisingly capable little machine.
That sprite hardware was particularly useful and the machine attracted games from some pretty serious Japanese developers, including Namco and Konami.
There were M5 versions of arcade games including Mappy, Dig Dug, Galaxian, Bosconian and Super Cobra.
Not bad for a computer hardly anybody has heard of.
The problem wasn’t really the hardware.
It was everything else.
The M5 arrived late into an absolutely bonkers UK computer market, cost around £150 and simply didn’t have the enormous software libraries already appearing for machines such as the Spectrum.
And that creates the classic computer death spiral:
Not many owners → not much software → fewer people buy one → even less software.
Oh dear.
By 1984 the price had apparently fallen to under £50 as CGL tried to shift the remaining machines.
Ouch.
So that was the end of the M5?
Pretty much.
Sord itself didn’t disappear immediately, but the M5’s brief attempt at conquering the British home computer market was over.
Which is a shame, because looking back at it now, it’s a fascinating little machine.
It’s got a Z80 processor, proper hardware sprites, decent sound, cartridges, cassette loading and hardware remarkably reminiscent of the MSX standard that followed shortly afterwards.
It was basically in the right place…
…at completely the wrong time.
And that, of course, is precisely why I wanted one.
Because anyone can buy a ZX Spectrum.
Where’s the fun in that?
So what did I actually buy?
Well…
A computer.
That’s it.
No power supply.
No cartridges.
No manuals.
No cables.
No clue whether the bloody thing even worked.
What I did get, for reasons known only to whoever assembled this particular bundle, were two Dragon joysticks.
Yes. Dragon. As in the Dragon 32.
They have absolutely nothing whatsoever to do with the Sord M5.
Excellent.
This presented me with a couple of fairly fundamental problems.
Firstly, I couldn’t turn it on.
Secondly, even if I could turn it on, the M5 normally requires a cartridge to actually do anything useful.
And I didn’t have one.
So I’d managed to buy an obscure 1980s Japanese computer that I couldn’t power up and, even if I could power it up, couldn’t use.
£110 well spent then!
Still…
How hard could it possibly be?
Okay, let’s give it some power!
First problem then.
Power.
Unsurprisingly, the Sord M5 doesn’t use a nice, convenient power supply that I happened to have lying around. It needs several different voltages supplied through a 6-pin DIN plug.
Hmm.
What does provide several different voltages and which I did have lying around?
An old PC ATX power supply!
Perfect!
Well… sort of.
The required voltages were available, so after figuring out which wires I needed from the ATX supply, all I had to do was connect them to the appropriate pins on a 6-pin DIN plug.
Simple.
Except wiring DIN plugs is one of those jobs that sounds incredibly easy until you’re actually doing it.
Tiny pins. Tiny numbers. Wires everywhere. And, crucially, the pin layout looks completely different depending on whether you’re looking at the plug from the front or the back.
You can probably see where this is going.
I carefully wired everything up, checked it, plugged it into the M5 and…
Nothing.
Bugger.
Fortunately, the ATX power supply has built-in protection and had simply shut itself down.
Which was rather lucky, because I’d wired the DIN plug the wrong bloody way round.
Oops.
After briefly contemplating the possibility that I’d just killed my newly acquired and particularly obscure computer before I’d even managed to turn it on once, I rewired the plug.
This time I checked it from the correct side.
Then checked it again.
And probably again.
Right.
Let’s try that again…
Here are the connections you need. I’m sure you’re not an idiot and you wouldn’t wire this back to front like I did!
IT LIVES!
Well, not quite.
With my newly corrected power supply connected, I flicked the switch and…
Nothing.
Absolutely nothing.
No picture. No reassuring beep. No smoke either, which at this point I considered something of a victory.
Out came the multimeter. The voltages were getting to the computer, so my spectacularly bodged PC power supply appeared to be doing its job.
It turns out this is normal.
For reasons best known to Sord, the M5 doesn’t actually start properly unless there’s a cartridge plugged into it.
Excellent.
You may remember that my extensive collection of Sord M5 cartridges currently consisted of…
none.
I could buy one, of course.
Except M5 cartridges aren’t exactly falling out of people’s lofts in 2026, and even the BASIC cartridge was going to cost considerably more than I fancied paying just to find out whether the computer worked.
Then I discovered something rather interesting.
Get the jumper wires!
The M5 can apparently be persuaded to start without a cartridge by bridging a couple of connections on the cartridge port.
Specifically, pins 2 and 3 (+12V) need to be connected together, along with pins 4 and 5 (+5V).
Easy!
Even better, why bother taking the whole computer apart and soldering anything when I could simply stick a couple of jumper wires directly into the appropriate pins of the cartridge slot?
What could possibly go wrong?
Well…
The wires touched.
There was a spark.
And I set fire to it.
Bugger.
Fortunately, I managed to disconnect everything quickly enough and hadn’t actually killed the computer.
Probably.
At this point I decided that perhaps poking loose bits of wire carrying +12V and +5V into the cartridge port of an irreplaceable 43-year-old computer wasn’t one of my better ideas.
So…
Get the soldering iron!
This time I did it properly.
I took the M5 apart, flipped the motherboard over and soldered permanent links directly onto the underside of the cartridge connector: pins 2–3 for +12V and pins 4–5 for +5V.
Much neater.
Considerably less flammable.
I put everything back together, connected my cassette lead and switched it on.
CLICK!
The cassette relay operated.
Bloody hell!
The supposedly dead, cartridge-less, power-supply-less Sord CGL M5 I’d bought with two completely unrelated Dragon joysticks was actually alive.
Better still, it was now sitting there waiting for me to feed it a program from cassette.
There was just one tiny problem.
I didn’t own any Sord CGL M5 cassettes either.
Of course I didn’t.
Time for a tape!
That CLICK! was important.
It was the cassette relay.
The M5 was now sitting there patiently waiting for me to give it something to load.
Excellent!
Now, I may not own any Sord M5 cassettes, but that’s not normally much of a problem these days because I have a TZXDuino.
For the uninitiated, a TZXDuino is a wonderful little device that pretends to be an old-fashioned cassette player. Instead of spending twenty minutes trying to find the correct volume setting on a forty-year-old tape recorder, you stick tape images onto an SD card, select one and it sends the audio signal directly into the computer.
Magic.
There was, however, another small problem.
I didn’t have a cassette lead for the Sord either.
Of course I didn’t.
Fortunately, after a bit of digging around, I discovered that the M5 uses the same cassette connections as MSX computers.
And I did have an MSX cassette lead!
Ha!
For once, something I already owned was actually useful.
So, computer waiting for a tape? Check.
TZXDuino? Check.
Cassette lead? Check.
All I needed now was some Sord M5 software.
A quick rummage around the internet produced a collection of M5 cassette images.
Brilliant!
Stick one on the TZXDuino, press play and…
Nothing.
Hmm.
Try another one.
Nothing.
Oh.
It turns out that, despite supporting an impressive collection of old computers and tape formats, the TZXDuino doesn’t actually support the Sord CGL M5.
Bugger.
So I’d successfully built a power supply, accidentally tried to set fire to the cartridge port, taken the computer apart, soldered jumpers onto the motherboard, persuaded it to enter its cassette loader, found a compatible cassette cable and obtained some software…
…only to discover that the device I was planning to use as my cassette player couldn’t play it.
Back to the drawing board!
So what can I actually load on the Sord CGL M5?
There was another slight snag.
Remember how the M5 normally needs a cartridge?
Well, it turns out that bypassing the cartridge doesn’t suddenly give you access to the enormous Sord M5 cassette library.
Far from it.
After considerable digging, I discovered that the number of cassette programs I could actually load directly into a cartridge-less M5 was…
four.
Four!
Still, four is considerably better than none.
These particular programs are machine-code tapes that can be loaded directly by the M5’s built-in cassette loader. Most other cassette software expects you to have BASIC loaded from a cartridge first.
Which I didn’t.
Obviously.
So now I had four programs I could theoretically load, a computer patiently sitting there waiting for them, and a TZXDuino that couldn’t play them.
There had to be another way.
Back to the future!
If I couldn’t persuade the TZXDuino to play Sord M5 tape images, I’d have to go slightly more old-school.
Well… sort of.
The tape images I had were in CAS format, but I found a little utility that could convert them into ordinary WAV audio files.
A WAV file is, of course, just sound.
And what do modern computers have that can play sound?
Speakers!
Although connecting the M5 to those would be fairly pointless.
More importantly, my laptop has a headphone output.
So I converted one of the precious four cartridge-less programs to WAV, connected the laptop directly to the M5 using my conveniently compatible MSX cassette lead, selected the file and prepared to press play.
This was getting ridiculous.
I was now using a modern laptop pretending to be a cassette recorder, connected via an MSX cable to a Japanese computer from 1982, powered by an old PC power supply, with bits of its cartridge port soldered together because I didn’t actually own a cartridge.
Surely this wasn’t going to work.
Was it?
CAS → WAV: The utility I used was castool, part of the MAME tools collection. It understands the Sord M5
.castape format and can convert a cassette image into a normal WAV audio file which can then be played into the M5 from a PC, phone or other audio player. You can download the MAME tools from the official MAME releases page;castoolis included with the tools package.
The command you need is:
castool.exe convert sordm5 “<full path to your .cas file>.cas” “<new filename>.wav”Connect the ear connector to your headphone socket, and play the wav file with the VLC media player. Laptop volume at 100%
Surely this isn’t going to work…
There was only one thing left to do.
I connected the laptop’s headphone output to the M5, selected my freshly converted WAV file and pressed play.
The laptop started making the sort of horrible screeching noises that anyone who owned a computer in the 1980s will immediately recognise.
And the M5…
…started loading it!
Bloody hell!
For the first time since buying the thing, the computer was actually doing something vaguely computer-like.
There was still plenty of opportunity for it all to go horribly wrong, of course. Anyone who remembers loading games from cassette will know that starting to load something and actually finishing loading it are two entirely different achievements.
So I waited.
And waited.
And then…
It worked!
Zac Banic!
The first game I successfully loaded was Zac Banic.
Never heard of it?
Nope. Me neither.
But at that particular moment it could have been the worst game ever created and I would have happily played it for hours.
Because there it was.
On the screen.
Running.
I’d started with a bare Sord CGL M5 with no power supply, no cartridges, no cassette lead and two completely irrelevant Dragon joysticks.
I’d built a power supply from an old PC PSU, wired the plug backwards, accidentally set fire to the cartridge port, soldered links onto the motherboard, discovered my TZXDuino was useless, found an MSX cassette cable would work, tracked down one of the grand total of four programs that could load without BASIC, converted it to an audio file and played it into the computer from a laptop.
And after all that…
I had a working Sord M5!
Hurrah!
So… now what?
There was, however, a fairly obvious problem.
Four programs aren’t very many.
And while it was enormously satisfying to finally get Zac Banic running, virtually everything else I wanted to try on the M5 still required a cartridge.
Particularly BASIC-I.
I could, of course, simply buy one.
So I had a look.
Then I looked at the prices.
Oh.
Bugger.
