Amstrad CPC 472: The Tax-Dodging Computer
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- เผยแพร่เมื่อ 14 ต.ค. 2024
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Today we look at the very unusual Amstrad CPC 472. We learn about its colorful history, and then we open it up and look to see what exactly it's inside. And it's a good one that apparently fooled some engineers back in 1985!
We then clean and restore the keyboard and the case. The tape deck needed some cleaning and lubricating because it had trouble loading games and even playing back some tapes.
In the end, we managed to leave it looking almost as good as new.
About the Amstrad CPC 472:
auamstrad.es/h... (in Spanish)
www.cpcwiki.eu...
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Spain: Amstrad everyone with 64k ram has to pay taxes.
Amstrad Slaps on PC : This baby has 72k ram inside.
I'm amazed by the great level of English you have, I didn't believe the fact that you are Spanish, you do it as good as many North American peers, I thought you were an American living in Spain, congratulations for all your contributions
Thank you, although it's not that impressive considering I lived in the US for a long time 😃
I’m from the UK and have yet to meet a North American who actually speaks English ;-)
Great video Noel, I'm really enjoying strolling through your older videos to see what I missed.
Thanks! Glad you're enjoying the back catalog 😃
alan sugar was a genius. a 472. absolutely love it. thanks for sharing noel i am sitting here with the biggest grin on my face knowing this.
Makes me wonder if those superfluous chips had been scrounged from a faulty parts bin.
As a matter of fact, when I was researching this, I read somewhere that sometimes different computers would have different 74XX chips, which supports your theory. I was tempted to pull them out and test them, but didn't get around to that.
@@NoelsRetroLab Sinclair used chips that were faulty in the original spectrum and used only half of the memory of them because they were cheaper even using 2 of them than using a working chip. I expect there were lots of faulty chips washing about. I expect that the legislation probably said that the computers had (contained) more than 64K not that it was actually used or had to work :)
@@stevewhitcher6719 I have made a switch to create a 80k Zx Spectrum, with the same chips, never experienced a problem using both banks.
@@pcuser80 May be they ran out of duff chips? Thankyou for your comment.
More than likely given Alan Sugar's attitude of chucking a lot of components in a box and making it look good cos the general public are too stupid to know the difference. Unfortunately this attitude caught up with him when he released the CPC plus range saying people would not know the difference between 8 bit and 16bit...how wrong he was...by that time the 'bit war' was just around the corner... 16 vs 32 vs 64 etc...remember the ATARI Jaguar commercial? or SEGA 'Blast' processing?? All marketing ploys.
Reminds me of a rumour that in some radios there were transistors on the board which did nothing. But were there for marketing on the basis that more transistors would be seen as a better radio and could be sold at a higher price.
Haha, I hadn't heard of that, but I wouldn't be surprised at all if that was true! 😀
I like that you use '3-en-uno' oil for a Spanish CPC
Haha, fitting, isn't it? :-)
Estoy leyendo “Queremos su dinero”, la biografía de José Luis Dominguez escrita por Jesús Martínez del Vas, y acabo de descubrir que hubo un CPC472. En cuanto vi que tenías un vídeo sobre él no lo dudé dos veces. Te sigo desde hace tiempo.
One could argue: The Commodore 64 also had more than 64k. It actually had 64.5 k of RAM because of that 1024x4 bit static color RAM chip. And that chip even did something useful.
Did Commodore try?
couple tricks you can do with idle tires and the take up reel. first! all the reel does is take up slack. the cap-stad and cap-stand roller are what pull the tape past the head, that first roller past the head. then the reel and idler pully ( idler wheel spins the take up reel) takes up the slack created by the cap-stand and cap-stand roller. you can use acetone to clean the surface of both rollers but you must use alcohol to clean off the left over residue from the acetone. scrub hard with the acetone with a q-tip. If the rubber has already turned soft and sticky then don't apply acetone or you'll just make a big mess. at that point you just need to replace the rollers.
also old drive motor belts, if that have hardened in place you can place them in hot water then clean them with acetone and then alcohol. the hot water will make them lose their memory of their shape from sitting in one spot for many years. and then i take a paper towel and pour some acetone on it then i pinch the drive belt between my fingers and the paper towels and pull it through all the way around then rotate the belt 90 degrees so i clean all 4 sides and then repeat with alcohol.
you be surprised that the belts and rollers will come back to life.
just remember, if the rubber is bad the acetone will make it turn to a soft sticky blob. hope this helps you in the future
Typical Amstrad. Throw some old tat inside that does nothing and put a sticker on it saying it's new and improved. LOL.
I'm up to date now. Can't wait for your next video.
That's some real binge-watching you did right there! :-)
But can the RAM in the CPC464 actually be upgraded for real. Are there mods you could do to have more than 64K.
@@simontay4851 Yes, You can get an expantion card that holds Megabytes. Or if you preffere you can upgrade the RAM to 256K. (I think)
4164 is 64 k x 1 bit DRAM, in order to work in 8-bit computer, you need... 8 such chips. I can't believe anyone could get fooled by this.
Hahaha... very good point! I didn't think of it initially. I guess you could store a bit plane of half a screen. :-) :-)
That's what I immediately thought. I was expecting something like an 8K byte static RAM chip since that at least would make some sense.
@@NoelsRetroLab Or a parity bit
This is hilarious! I never heard of it. Classic 80s tax dodge + bodge job!
Cool! I have one of these 472’s. Need to dig it out to see if it works.
@Noel's Retro Lab so in the video you put a dab of oil on top of the pulley of the motor but that is not rotating around the metal axle, it is in fact solidly attached to the axle and it is the axle that rotates. The oil would need to go under the pulley to where the axle makes contact with the motor housing. Am I missing something?
No, you're right, that was useless. I should have put the oil from under the pulley so it would get into the moving part of the motor. I probably did that because I often have to lubricate some of the moving gears in the tape deck that rotate around a static axle.
Awesome video was great learning about this - really interesting - this is one of the best retro channels on youtube!!. Greetings from the UK!
I first saw your Inves Spectrum video and then this one, but only when I saw that yoghurt bucket did I notice that you were actually in Spain lol
Greetings from Malaga
Aprovechando los ordenadores que tengo a mano :-)
For the very damaged blue keys have you tried a cutting compound? If you use an aggressive polishing compound on a rag you may be able to remove the damaged layer if it is not too deep. You would unfortunately lose the texture but that may be able to be restored by spritzing with acetone? Like a super fine mist to melt the surfaces. Of course a DIY sandblaster like those made with a compressor blowgun and a water bottle may do all of the steps at once.
Nice video. Would love to see a room tour of the retro dungeon! Thank you.
Loved the drop of oil to the motor spindle that did exactly nothing haha. The belt seems to be too tight to me. Also the contact cleaner actually works on rubber clutches, in worst case - high grit sandpaper does. Might also worth checking (and cleaning) the capstan and roller.
Aprovechando la reclusión viusiana he tirado de este video para hacer un repaso a la casete del 464 que no me leía los juegos con carga turbo y listo. Funcionando y sin ruidos! Muy agradecido.
Genial! Pues a darle caña ahora :-)
I noticed you using the car dash chemical. You should try the "Back to Black" chemical from the same maker.
It does impressive things for plastic and rubber and rubbery things. You ahould be able to treat rubber belts with it if you clean the drive side or if its toothed. It removes the oxidized rubber and revitalizes. The plastics also get some rejuvenation like it soaks in. It also cleans well, so in the case of keys it would bring the white back.
Hey Noel! I love your videos! keep up the good work my friend!!
Very interesting, especially the dummy 8k circuit. One thing you didn’t mention was that the 472 is physically wider than the 464. That also applied to the PCB too, which seemed to be the same just wider. Was this also part of the ruse, to make it physically wider just to give the impression that it really was different to the 464?
It's amazing that they actually used a different plastic mold for the case with the markings in Spanish. Molds are expensive.
France and Spain were the market for this product
For the cracked clear plastic you can use a super thin high wicking super glue. You can get it from hobby model stores. It will wick down into the crack and make it disappear.
Funny that the initial splash screen says 64k and not 72k confirming the extra 8k was bogus.
Hahaha, true! They didn't even change that! :-)
The drive to the take-up spool _should_ slip during PLAY mode! The tape is being moved at a constant speed of 4.75 cm/sec. by the capstan and pinch roller. The effective diameter of the take-up spool including all the tape paid out so far is steadily increasing from the beginning of the tape to the end, so the drive slips more and more as the tape plays on.
During fast wind, a cog engages with teeth under the spool carrier to transfer the full effort from the motor to transfer the full effort of the motor to the spool without any slippage.
As a famous (now deceased) Romulan once said: "IT'S A FAAAAAAAAKE!"
WOW .. me recordaste cuando reparaba la XC12 estirando la banda para que funcionara, buscando en las tiendas una que tuviera mejor resistencia.
con eso se me quitó el miedo a abrir las computadoras
great video as always Noel, i notice that when it boots it says 64k, so it wasn't trying to hide the extra 8k much at all, also, where's the missing LED (power) i don't see it (end of video), maybe you can talk about that in another video, as mine doesn't work at all in my latest 464 (cpc powers on, but LED does not).
Good eyes! I noticed that afterwards!! When I pushed in the LED, it bent instead of going through the whole. If you notice, the thumbnail for the video has the LED fixed and coming through as it should.
Really enjoyed seeing your take on restoration. The CPCs are gorgeous in their aesthetic-one day, I'd love to own one and learn more about them.
I do remember Amstrad sold then in Spain a compact music system with a equalizer connected to nothing, just as a fancy add on... 😂
For the plastic door at the end, my advice is to just get a thin A4-sized sheet of plexiglass (acrylic) for like 4€, then whenever you need a lid for something like this, simply cut out one from the sheet.
Qué curioso ha resultado el 472!!!!!
It looked like you put oil on top of the drive pully from the motor vs the motor sintered bearing itself. Weird setup, I guess that's not a pushed on plastic pulley?
Otra vez más gracias por otro vídeo lleno de aprendizajes. Algunos como yo agradecemos que venga todo tan desmenuzadito y tan bien explicado. Cuando nos veamos, te debo unas cuantas Coca Colas (o lo que prefieras) ;-)
¡Gracias! :-)
Very nice job. Any chance for older Sinclair machines, like ZX80/81?
Yes, as a matter of fact I have a pretty beat up ZX81 sitting on my shelf of "to be repaired". Stay tuned :-)
Those decades old mechanics are usually dry of all oil and lubricants that manufacturer used. Vaseline soaks lots of dust over years and then became exact oposite what it should be.
Loved the video.
So glad! Thanks!
well.. I have a 5 wheel truck, if you count the spare underneath. This is pretty much the same :D
The tape deck wasn't working because the pinch roller is very dirty, you need to use rubber restorer or tetrachloroethylene to clean it up and it will work fine.
yknow, im spanish and this is the only computer i ever seen with translated labels in the case
software is usually the only thing that gets translated at least over here
The Z80 architecture allows for memmory banking. My MSX can have 4 slots with 4 pages, and eache page can bank 4 times. Imagine a cube 4x4x4 and every page have 16kb. So, 64 pages total times 16kb equals 1mb. WOW! It almost run crisys!
What would happen if the extra RAM was available to the system? Has anyone made the non-working extra RAM actually work?
Useless just an addition to avoid paying the tax. For my part, I never succeeded in using this additional ram which remained invisible in the end and unusable.
@@texmex3343 That wasn't quite my question. What if you could integrate the extra RAM into the system?
@@ShaunBebbingtonyou can with bank switching for anything over 64k. Noel did a vid on it recently I think. Theres no bank switching option on "64k" machines, so the additional 8k wouldn't be readable without it.
One question. Because this 472 use the ROM from 664, mean it that has the disc operation commands?
What type of oil are you using for lubricating the tape. I have a similar problem with my Spectravideo tape. Thanks!!
I think it was lithium grease or teflon oil. I forget which of the two I used in that video (but those are the two I use in a regular basis).
So a question from a relative noob - Was the ram chip completely fake or useable if taken out? Or just the board connections?
Hello Noel! I have just purchased a Spanish version of the 464. It's labeled 464 and has Spanish keys (QWERTY keyboard though). Would you know if the BASIC programming environment (ROM?) is in English or Spanish?
All Spanish keyboards are QWERTY, so that's normal. Some of the 464 come with the Spanish keyboard with the Ñ and a couple symbol keys moved around and some of them come with the English keyboard. The BASIC ROM is language independent, so there's no worries there. Pretty much the only thing the Spanish ROM does is has the different keyboard layout as far as I know. So unless you're planning on changing the keyboard itself, you're probably good.
@@NoelsRetroLab Thank you Noel for sharing your knowledge. Fantastic channel!
Nice job :)
This perhaps explains the glut of Spanish Amstrads in the UK. I have 3 of them!
Buenas tardes. Me gustaría saber si los videojuegos del ordenador Amstrad CPC 464 son compatibles para el ordenador Amstrad CPC 472. Gracias.
Sugar was a character!!!! 8k more
I’m glad to see that Spain’s government is as mental as the Dutch. For some reason making solid logical (tax) laws is not in the realm of these so called elite. A mentally well developed person would tax systems physically lighter than 35KG that would cover all imported home computers :)
Quite cheeky and brilliant of Allan Sugar to add a cheap 8K avoiding extra taxation and giving the Spanish more bang for their pesetas :)
Or possibly a cheap 0K, if those were all bad chips. It still cost money to build and install the dummy unit, so the taxes must have been pretty substantial.
Myabe the red ink on the tape deck fades more on the 472 because they are from spain - with more sun ;-)
Please do a video on how to power an Amstrad without the monitor.
Oh good idea! I've been meaning to expand into some short-form videos and that would be perfect for that.
In fast way: The aditional 8K chip was here to avoid a tax. Imported computers with 64K or less should pay in these years an extra tax. This tax was aked by computer manufactures after seeing that 48 and 64 k computers have big sales while more "serious" (and expensive) computers lays on stores...
The 8k aditional chip was soldered on a board, but not connected to anything. This means that the chip is no powered, accesed and used.
The CPC 464 or 472 were still good family computers at that time, for the price of a Commodore 64 you had a CPC with the screen included for the same price, hence its success in France and Europe in terms of sales. Otherwise at the level of the added ram 72 Ko this one remained invisible, unusable in the end, it was just an addition not to have to pay the tax at the time. ⌨
13:01 i am wondering which part of 472 lie what this Lego dude into. Switching single 8k bank manually? :D
Why do you use window cleaner to clean the keys? The reason I ask is I have recently started using window cleaner to clean Audio cassettes and their cases it was completely illogical because window cleaner is for glass not plastic. I just had a bottle handy. But i've found that removes any dirt/ grease and gives the plastic a sort of shine. On a similar note i've started using car compound. to remove the top layer of plastic may be worth a try to turn your grey buttons blue, but would take the lettering of course.
It's just something I picked up along the way and seems to work really well. You hardly have to remove it too, unlike soap. Yeah the lettering would be affected by removing a thin layer, so that wouldn't be ideal. I need to come up with some good solution to that because I love those bright colors!
I think when you put oil on top of the motor pulley, it was for nothing, because isn't the motor axle just glued or at least tightly fit to the pulley, so the oil could not go to the bearing that is below the pulley?
Yes, you're totally right. Don't know what I was thinking at the time 😜
did you miss cleaning the tape deck keys - they looked really grubby, or were they past saving?
Haha, I don't know! Looking at it again it looks like they were mostly yellowed, so it wasn't a matter of cleaning them but retrobrighting, so that's probably why I left them that way.
@@NoelsRetroLab there's one thing I didn't miss... That minifig at about @13:02 ... ;)
Great job!
Thanks!
@@NoelsRetroLab this afternoon I found my old 464 in a box in my mum's garage, complete with original colour monitor. Sadly not enough room in the car to take it home, this time....
@@djdublo Nice! That must have been a fun find. Hopefully you'll get it up and running no problem. Good luck!
I can't believe they could get away with that. I mean no real engineer who was tasked to inspect whether it was really a 72K computer would miss this. I am guessing some money exchanged hands to make that fake board "work" :-)
My question is are the chips even real or defective? It would be a pretty awesome test to swap the 8k of ram and see if the machine still works.
They aren’t connected to anything, so swapping it won’t matter.
@@KateGrayCode I think they meant swap the do-nothing chip into one of the active locations and see if it works.
What if you used bodge wires to connect those fake traces or had PCBWay create a Real PCB for those chips?
HUN: a motor csapágyára a szíjtárcsa alatt kellet volna olajat adni. így csak össze koszoltad a tárcsát.
Haha, yes, you're right! I don't know what I was thinking. That was the wrong place 😃
@@NoelsRetroLab I love watching your videos, you do wonders with these old machines.
27:36 those Lidl 30% discount stickers look just as unreadable in the Netherlands as they do in Spain! 🤪
🤣🤣🤣
I reckon the faded colour has something to do with....uhm...the Spanish market. Y'know..?? 🌞
oh wow I expect this is a rare find
It actually isn't super rare in Spain. You can still get them for reasonable prices.
Can it actually access that extra 8k? The bootup says 64k....
The 8mhz z80 cpu is faster than the c64's cpu I heard.
What year do certain people go up to?
Instead of giving us a green screen monitor, Amstrad should have put a proper sound chip, scroll hardware, and a blitter inside the machine. The z80 was too slow to push 16K video memory around. Sugar surely didn't think the CPC would be used for anything but games?
I think the chip is fine, and scroll... you kind of have it, but have to work hard at it. The blitter would have been totally awesome. I keep mulling around in my head if it would be possible to make an extension for the CPC that added exactly that (strictly through the expansion port).
@@NoelsRetroLab Horizontal scrolling *could* have been relatively straight forward to implement. If the CRTC data lines were piped through the Gate Array, the Gate Array could have had an internal counter which would wrap the address back to the beginning of a horizontal line represented in memory. The Gate Array (GA) counter would be incremented on every byte requested by the CTRC, and then wrap on a set value. This way the Z80 would only have had to move a small chunk of graphics data per frame as the screen wrapped over itself (plus sprites). As far as the CRTC is concerned it's just reading a static 16k memory page. Not sure if the 6128 page swapping logic extended to external memory carts (aka above 128k) but if it did then you could set the 16k page the CTRC sees to an external memory unit BUT the external memory unit would need to, at a minimum, know when a frame has refreshed V-Sync. This *might* be accomplished by the CURSOR line which is available on the expansion bus. If I interpreted the documentation correctly, set the trigger address for the CURSOR line to go high on the last byte read by the CRTC indicating the current frame has completed. BTW and probably should have led with this, you can program the CRTC to read memory in 'vertical' strips as the display beam goes horizontally. Seeing as the CRTC can scroll vertically quite smoothly you could probably set it to this mode and get it to scroll horizontally just fine but you'll need to wrap your head around how to set up the memory correctly.
Great video, never seen one before. It would be so cool if you could mod it. Make it a real 72k. 👍🤓
Just read down and saw the comments. Shame it can't be a 72k. 👍
Right! Unless we want to be able to toggle a 1 bit bank across the 64K. Haha...
I am reading a book on how Volkswagen programmers cheated with the pollution control systems of their diesel cars. In both cases we have engineers/programmers deliberately dodging the rules.
Usually it’s marketing and sales forcing the engineers to do it.
I'm sure they could have made an even cheaper bodge with just a little more thought.
3:43 A Good Day to Euro Hard?
Sorry Noel, but my engineering brain cringes when seeing the tape mechanism "repair". That first drop of oil was a waste of oil. The pulley directly connected to the motor spindle is a friction connection and you want it to grip, not slip. Where the oil would have made a difference was to remove the pulley and oil the motor bearing, clean the shaft, making sure no oil is on the part where the pulley attaches, and then attach the pulley again. As to the two friction rollers, some rubber-renew or even dropping them in bowling water for ten minutes would have renewed them and softened them a bit.
As to the PT Barnum daughter board, technically it is 8K of RAM in a 64Kx1 configuration. The law didn't state it had to actually be connected to anything. The chips, even if working still would not have been enough to support DRAM multiplexing and refresh. One DRAM chip and a couple of LS logic chips are far cheaper than an 8K static RAM chip alone. So I see why they did it. These all could have been taken from QA failure bins too.
Buen vídeo. Únicamente te falta hablar "Cristiano" y ya lo bordas. Jajajaja
omg my first pc, I remember green screen and basic
Is't the most obvious difference not the fact the 472 is slightly bigger?
Is there any way of actually using more than 64K of RAM in a CPC464 so it can _really_ have 72K or more RAM.
I'm afraid not. What it has is a 64K x 1 bit RAM. So at best you could substitute 1 bit of the other 64KB with that chip which is kind of useless 😃
They misspelled 'casete'
i wonder if its actually possable to make it 72k with real (working) memory and ICs for bank switching..and rewired rom expansion board...
Not with that RAM chip. That's what makes it so hilarious: It's a 64x1bit RAM chip, so at most you could swap out 1 bit out of every byte in the addressing space. Hahaha!
@@NoelsRetroLab ROFL.. i shoulda expected somethin like that from Lord Sugar! :P
@@WacKEDmaN I wonder how much of that he was aware of, vs how much it was the local Spanish distributor pulling that stunt.
Does this mean the commodore 64 also avoided the tax, since technically it has ~64.5KB of RAM..... 64KB main ram and 1000 nybbles of colour ram......
Love that fake extra RAM. Any chance you could make it work, giving you the only genuine working 72K machine?
No! That's the thing, think about the chip they added: It's a 64 bit x 1 chip. If you hooked it up you could replace 1 bit of every byte of memory in the computer with a bit from that chip. But that's pretty useless! So any engineer at the time could have thought about it for a minute and realized it was fake!! 🤣🤣
@@NoelsRetroLab I genuinely didn’t get how this worked until I watched your adventure with the SVI - the one with the glue, sparking fuse and green screen. You had a display failure, caused hey one of the memory chips not working properly, and that’s when I understood how the RAM worked.
@@HairyDalek Right! That was a very visual demonstration! I hadn't thought of that 👍
So you're based in Spain?
Yes, that's right.
Shame on Amstrad for deceiving its customers and dodging taxes....
@@de4455 Bad faith? That's hillarious, dude! That's a sovereign decition. Spanish goverment doesn't need your aproval on one hand, I don't care about it on the other. The more sovereign a country is, the more it grows.
LOL
*YES ..SOUND VERY "STRANGE" I HAVE "THIS" 464 WAS THE NAME.!!. THEN THE "DISC" MODEL 664*
*.. **#NONE** OTHER I HAVE "SEEN" OR "READ ABOUT" IN MY LIFE .. (STARTED IN 80s TO WORK ON "PC")*
*FUNNY*
(no reply)
Anyone really tried to use hydrogen peroxide to restore these? Just curious what they'll like after retrobright.
There isn't much to retrobright in these computers. The only thing that really changes colors are the color keys. In my limited experiments, I was never able to restore the vibrant greens and blues. The retrobright with hydrogen peroxide took them from a grayish-yellow to a lighter grayish-yellow 😞 If someone has a method for restoring the color of those keys, let us know!
@@NoelsRetroLab Did you have any success on the normal one such as Apple //c?
@@johnsonlam Not with Apple IIc keys, but with Amiga 500 and Atari XE ones. So yeah, that works fine with light-colored keys.
Could AMS(trad) still get justice for this fraud ?. The evidence is significant enough, although many years ago.
There are cases of murder that was committed and cases have been brought up decades of years later following new evidence. Yes it's not as bad as that but it's an offence that was deliberately committed.
No idea. I assumed they couldn't. Besides, Amstrad stopped doing business 10 years ago, so I very much doubt they can go after them.
Looks like you don't understand how the tape mechanism works.
Everything else Amstrad sold was utter garbage.... but people seem to really like these computers and they seem to have lasted really well.
I wouldn't say it was total garbage, but they were generally cheap, uninspired, and just going for the money. And yet, the CPC range was great. Maybe they were just lucky, or they had great engineers.
Ha! That's awesome, fake tracks.
It horrifies me that Amstrad bought Sinclair and was turning the Spectrum family into the CPC junk. Thank god they stopped producing them.
The awful multi-hop microscopically label because coal unpredictably stuff athwart a tense aftershave. common, terrific prison
Alan Sugar is one crafty crook, will do anything for a pound, even so it was good that they did it to get around those crappy tax laws.
Good video.
What if you used bodge wires to connect those fake traces or had PCBWay create a Real PCB for those chips?