Hi, does somebody have a cpc472 schematic? Most sources say that the extra 8K RAM is not connected. But after seeing this article, http://www.cpctech.org.uk/docs/cpc472.html, it seems as if it is connected in same way.
Here's a description of the two keyboard versions, http://perso.wanadoo.es/amstradcpc/cpc/cpc472.html
Here are some photos of the top/bottom side of the daughterboard, http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=591
As the author of the schematic/drawing stated, "it is not easy to see the source/destination of some connections", so the drawing is probably full of mistakes. Anyways, no matter if they are wrong, there seem to be connections.
Does somebody have a cpc472? It's difficult to see the conections under the white paint, but with a multimeter it'd be super-easy to test which pins are connected with each other.
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Some ideas about if/how it could work: To me, the schematic looks a bit too complicated to be a totally useless fake. On the other hand, there seem to be no RAS/CAS signals for accessing the DRAM, so it'd be difficult to access the whole 8K, but at least a few bits might be accessible.
Very interesting... thanks for bringing it up.
For all we know, maybe it was connected in a way that it did exactly nothing, so as to not be so obvious that it was a fake...?
If they went to the bother of making a daughterboard etc, you would think that it must have been connected in some way. Maybe it just wasn't accessable due to it having standard 464 Firmware? Or was there a 472 Firmware version? The screenshot suggests otherwise.
The other question is how it would be addressed. If I recall correctly, the bank switching works with 16K banks, so the extra memory would have to be:
A) connected to the PAL somehow?
B) addressed as "half of a bank" ?
No?
Bryce.
Well, I guess they *had* to make a daughterboard. They couldn't just plug the extra chip into a random position on the motherboard, could they? :D
But this makes me wonder: how much was the tax anyhow, so that they saw it more convenient to design and add all this thing to the machine? Any Spaniards in here? :)
It was a null connection... i.e. no connection to the main CPC motherboard.
Soooo that ribbon goes... to nowhere???
Quote from: Bryce on 09:02, 01 April 10
If they went to the bother of making a daughterboard etc, you would think that it must have been connected in some way. Maybe it just wasn't accessable due to it having standard 464 Firmware? Or was there a 472 Firmware version? The screenshot suggests otherwise.
The other question is how it would be addressed. If I recall correctly, the bank switching works with 16K banks, so the extra memory would have to be:
A) connected to the PAL somehow?
B) addressed as "half of a bank" ?
No?
Bryce.
Quote from: Bryce on 09:02, 01 April 10
If they went to the bother of making a daughterboard etc, you would think that it must have been connected in some way. Maybe it just wasn't accessable due to it having standard 464 Firmware? Or was there a 472 Firmware version? The screenshot suggests otherwise.
The other question is how it would be addressed. If I recall correctly, the bank switching works with 16K banks, so the extra memory would have to be:
A) connected to the PAL somehow?
B) addressed as "half of a bank" ?
No?
Bryce.
The cpc464 or cpc472 as far as I know don't have the PAL.
The daughter board is connected into the same location as the original 32K ROM is connected.
So it seems (unless there are additional connections under the pcb) that the the small PCB only has access to the signals the rom has.
The extra 8K was just a tax dodge, the 8k was non funtional. I think the 472 came in two different versions though? Maybe I'm wrong, but the early models didn't feature the 'N' key, where later models did. Maybe the later model connected the extra memory?
Quote from: Gryzor on 09:34, 01 April 10
Soooo that ribbon goes... to nowhere???
Yes, of course we know all that. But the matter here is, if it was non-functional indeed, how come there are connections? That's what we're asking.
Quote from: arnoldemu on 09:42, 01 April 10
The cpc464 or cpc472 as far as I know don't have the PAL.
Oh yeah, sorry hadn't booted my brain this morning before posting, was thinking of the 6128.
Quote
The daughter board is connected into the same location as the original 32K ROM is connected.
So it seems (unless there are additional connections under the pcb) that the the small PCB only has access to the signals the rom has.
Indeed, it would need something to switch the Chip enable / output enable when the right bank / address was chosen.
Unless it was being initialised with ROM0 access, but using different addresses?
Bryce.
>> It was a null connection... i.e. no connection to the main CPC motherboard.
> Soooo that ribbon goes... to nowhere???
That detail isn't visible on the photos, too. But I think it's safe to say that the ROM chip is connected to the motherboard :-) The question is if the RAM chip and the two logic chips are connected, too. There are wires on the daughterboard, so they seem to be connected -- or are they dead-ends, ie. do the wires end shortly before reaching the soldering points?
Mapping the RAM to address 2000h (for example) would require more complex address decoding, mapping it to a larger region like 2000h..3FFFh would be possible, but then important areas of the ROM would be unusable. So, the two logic chips are probably not capable to map the RAM to memory - though they might map it as I/O ports.
The ribbon cable has 28pins, but the ROM uses only 27pins (pin1 is NC). So the extra wire could be used as /IORQ. Though that'd additionally require a small modification of the mainboard - the photos don't show the mainboards solder side, nor the region under the daugherboard - so one can't say if there's such a mod.
> But this makes me wonder: how much was the tax anyhow
Good question. Does somebody know details on that?
No matter of the tax. I wonder if the daughterboard with the three extra chips plus the rebadged case with 472 on it was actually cheaper than changing the letters printed on the keyboard.
> I think the 472 came in two different versions though?
Yup, the one with english keyboard (with the avoid the tax trick), and the one with spanish keyboard (when the trick no longer worked). The latter one could have been renamed back to 464, but for some reason they stayed with 472... either Indescomp had produced a lot of 472 cases & daughterboards that they needed to get rid off... or they thought that spanish users got familar with 72K machines, and won't buy lousy 64K computers :-)
Well, somewhere out there on the tinternet or in a Retro Gamer mag is an interview with Roland Perry or William poel where they actually mention that the memory was not usable, but was made to look as if it were. Don't forget guys, this is Alan sugar we're talking about, he used to buy equipment and re-badge it with the Amstrad logo. In his younger days, he was selling tv's from his mums house, and each customer would trundle into his bedroom only to be told it was his own tv, and he was selling it because he needed the cash. As soon as the guy had bought the tv, he'd put another one out and start all over again. The guy was a trickster, and a good one at that... fooling people was his game.
Which interview? Do you mean this one: http://perso.wanadoo.es/amstradcpc/interviews/roland.html or this http://amstrad.cpc.free.fr/amstrad/poel_e.htm ?
In that interviews, Roland Perry and William Pole both say that they never heard of the CPC472. As far as known, the daugherboard was made by Indescomp (spanish distributor), not by Amstrad (and thus nothing to do with Alan Sugar).
Anyways - the interviews don't say that the RAM is nonfunctional.
PS. Here was a cpcwiki user owning a CPC472, http://cpcwiki.eu/forum/index.php/topic,202.0.html unfortunately the other people in the forum were kidding (?) him and told him to pour destilled water on the mainboard, and to spray compressed air on it. Not so nice to scare people like that, but okay it was funny :-) the downside is that Tom left the forum after that suggestions, so we can't ask him about details. Does somebody else have a 472?
PPS. From http://amstrad.cpc.free.fr/article.php?sid=12 translated to english: "To avoid this tax, it was decided to add a module for 8 KB (which serve absolutely no purpose and are not even visible from BASIC) thereby increasing the machine to 72 KB of RAM."
That only states that the RAM isn't visible from BASIC, not that it'd be nonfunctional.
PPPS. Here http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=1058 is some spanish text, saying that the fee could range from 15,000 to 300,000 Pesetas per unit. How much would that have been in dollars or euros?
I'm not quite sure how we were "kidding him" when we advised him on how to clean the mobo. Both methods suggested are time-honored ones, and they work. Why would that scare anyone, and why would it be funny?
Oops, that wasn't joking? Compressed air sounded a bit surreal... like buying spray cans or air compressors... of course, cleaning a board with a small brush, and then blowing away the dust is the best solution. Just calling your lungs an air compressor sounds a bit mechanoid. And destilled water - if that idea isn't scary!
It's an interesting method though - as far as I understand, destilled water is non-conductive, so it can't produce shortcuts? But if you pour it on a dirty board, then you would get conductive dirty water, wouldn't you? And if you wait until it has dried completely, then you could as well have used normal water... or does that "rot" the soldering points? Anyways, I am feeling fine with dusty electronics, but pouring liquids on them - even if it'd be harmless - that's scaring me :-)
For the 472, I've checked the history of the cpcwiki article. The not-connected info seems to come from Mcleod ideafix, I've sent him an email, maybe he can confirm if he verified the info himself, or tell where the info came from. I guess he knows what he's talking about, though the sentence "difficult to turn the daughter board over and reveal the trick" is confusing me - since the photo of the turned board doesn't actually reveal anything.
Surreal??? You mean you have never seen an air blower for PC case cleaning? Or the air sprays they sell at computer stores? No, shire, not surreal at all!
Distilled water is, I admit, a bit more bizarre, but I have done it, and I know professionals who do it. You have a point about the dirty water being conductive, but I guess that if you make sure that whatever it is that you're cleaning has no charge you're on safe ground... Distilled water, however, is needed not for its non-corrosive capacity, but because you need to make sure it doesn't leave anything behind - that is, salts. So arguably you could use whatever liquid has no salts, like pure alcohol - it's just that water is much cheaper :)
We often clean PCBs at the place I work with distilled water with some alcohol added (dries quicker supposedly) and then blow dry it with compressed air. I can confirm that it works perfectly, we've never had a problem with this process. It has to be distilled to avoid salt (and other impurities) in the water getting left on the board, which would corrode the board over time. Obviously the board needs to be rinsed until there is no dirty water left over or it would (as nocash suggested) possibly cause short circuits or at least cause an unwanted resistance between solder points. I suppose we could use pure alcohol instead, but it might evaporate too quickly, or maybe they are just worried that the engineers might drink it :D
Bryce.
I recall a thread about washing your mobo/graphics cards in a normal washing machine and weather or not you should add extra stuff or not. Cant recall how it ended tho, but made me chuckle a bit. Still nothing wrong with the shower and hairdryer method i hear.
What is the other thing pro people do ? Ultrasonic bath or something?
Anyways, personally ive just used a compressed air can (same can for like 5+ years) and that is probably what most normal people do with eletronics.
Yeah, I guess you can put stuff in the washing machine - heck, while you're at it, put your cat and dog in there, too. They'll come out all clean. Maybe in pieces, but clean pieces.
Ultrasonic bath is a great way to remove grime, as it makes all dirt go loose. Many cameras use ultrasonic waves to clean the lenses. Where to find such a bath though, and at what prices, is another story...
Got some brandnew CPC472 super pictures from Mcleod ideafix - see here, http://cpcwiki.eu/index.php/472. They revealing how it "worked" quite well. He's also thinking about a way to remove the white paint completely, with chemicals or so.... I think best would be scraping or using sandpaper...?
Also changed some other things on the CPC472 page. I hope I got the timeline correct? There were four different 464/472 models in spain? And can somebody fill-in the "how much" pesetas/euros values?
Wow... see, you learn something new every day.
My question remains - how much did that ruse cost, especially against the cost of paying the tax?
Quote from: nocash on 21:05, 01 April 10
Which interview? Do you mean this one: http://perso.wanadoo.es/amstradcpc/interviews/roland.html (http://perso.wanadoo.es/amstradcpc/interviews/roland.html) or this http://amstrad.cpc.free.fr/amstrad/poel_e.htm (http://amstrad.cpc.free.fr/amstrad/poel_e.htm) ?
In that interviews, Roland Perry and William Pole both say that they never heard of the CPC472. As far as known, the daugherboard was made by Indescomp (spanish distributor), not by Amstrad (and thus nothing to do with Alan Sugar).
Anyways - the interviews don't say that the RAM is nonfunctional.
PS. Here was a cpcwiki user owning a CPC472, http://cpcwiki.eu/forum/index.php/topic,202.0.html (http://cpcwiki.eu/forum/index.php/topic,202.0.html) unfortunately the other people in the forum were kidding (?) him and told him to pour destilled water on the mainboard, and to spray compressed air on it. Not so nice to scare people like that, but okay it was funny :-) the downside is that Tom left the forum after that suggestions, so we can't ask him about details. Does somebody else have a 472?
PPS. From http://amstrad.cpc.free.fr/article.php?sid=12 (http://amstrad.cpc.free.fr/article.php?sid=12) translated to english: "To avoid this tax, it was decided to add a module for 8 KB (which serve absolutely no purpose and are not even visible from BASIC) thereby increasing the machine to 72 KB of RAM."
That only states that the RAM isn't visible from BASIC, not that it'd be nonfunctional.
PPPS. Here http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=1058 (http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=1058) is some spanish text, saying that the fee could range from 15,000 to 300,000 Pesetas per unit. How much would that have been in dollars or euros?
I'll need to get back to you on this, but I read it some years ago now. Apparently Alan Sugar was a bit of a trickster, and used a similar technique in his early range of Hi-fi models. I think it was something to do with him selling a hi fi model with 3 inbuilt speakers, and someone noticed at curry's that one of 'em wasn't actually wired up. It was a dummy 3rd speaker, put there to fool the public.
> It was a dummy 3rd speaker, put there to fool the public.
Cool :-) That hints towards Amstrad, maybe he told his devrs, "if somebody asks: you've never seen this 472 model, got that?" though maybe Indescomp knew something about trickery, too.
I guess the tax applied to all computers, not only imports. So it could be imported without tax, and modified it in spain before selling it. Indescomp seems to have purchased the 464 together with 664 ROMs from Amstrad, so Amstrad should have at least noticed that something strange was going on.
For the cost of the daughterboard: The two logic chips aren't too expensive. Though the 64Kbit RAM may have been a bit more valueable back then. And it might have been necessary to mount the daughterboard by hand. My guess would be around $5. And don't know how much $5 would be compared with 15,000 pesetas.
More info on Indescomp:
I'm not sure if you guys are aware of Indescomp, but basically a chap called Jose Luis Dominguez run this small outfit. He originally contacted Bob Watkins and asked if he could become Amstrad's distribution network seller in Spain, Watkins told him Alan Sugar wasn't interested in Spain and that Amstrad wasn't yet ready for such a thing. Dominguez had already approached Sinclair, but they told him no! Later he agreed a deal with Acorn, but the 2000 machines he purchased off them didn't sell. This left Dominguez on his knees with little money and no where to turn. This guy was basically a sales man, a one man band trying to seek his fortune.
He called Bob Watkins once more, in an act of desperation and asked if he could meet Alan sugar. Watkins told him to stop wasting his time, and reaffirmed that Amstrad wasn't yet setup to launch in Spain. Just before Dominguez contemplated putting down the phone, Bob Watkins said "Unless you have a game for us, sugar wants games?" Dominguez quickly remembered a game an associate of his was working on, and said "yes we have a game, but I'll need you to send me a CPC in order for me to modify it to work on your system". And with that Bob sent the CPC and agreed for Dominguez to meet up and demo the game to Alan sugar. When Dominguez finally met up with sugar, he recalls how rubbish the Amstrad building was, and how horrible Alan Sugar came across. The demo didn't go well either, the game wouldn't load, and sugar apparently moaned about Dominguez being a time waster. But he tried again and the game loaded.
Sugar and Watkins were happy with the game, and Sugar offered to pay him there and then, but Dominguez refused payment and instead offered the game to Amstrad as a gift. Sugar had never experienced this before, and asked Dominguez what he really wanted? Dominguez basically asked if he could sell Amstrad CPC computers in Spain. After a heavy conversation, Sugar agreed to loan and send Dominguez 4000 CPC's direct from Japan, with a 60day return on investment, but with it under the condition that Dominguez and his outfit would release ten games for the CPC. Dominguez accepted and the rest is history.
This is a great post. I knew some of the info, but not all of it... Btw, have you noticed that all this is not in the wiki article? (hint, hint!)
Its gonna feature more in the book... glad to know the stuff i'm discovering and writing about is of interest to people. Alan Sugars new book, your fired! Talks about Amstrad's history in great detail. Worth picking up.
Quote from: Gryzor on 08:36, 14 April 10
This is a great post. I knew some of the info, but not all of it... Btw, have you noticed that all this is not in the wiki article? (hint, hint!)
PPPS. Here http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=1058 (http://www.zonadepruebas.com/modules/smartsection/item.php?itemid=1058) is some spanish text, saying that the fee could range from 15,000 to 300,000 Pesetas per unit. How much would that have been in dollars or euros?
Colossus, webmaster of zonadepruebas, asked me to sort out the evidences we had, and to write that article. Some days ago he suggested me to extend the explanation in english, so here is a brief translation of it:
Hypothesis & Facts:
1. Some Spanish companies may have lobbyed for a tariff on imported computers, calculators and other electronic machines during the first half of the eighties*. As a result, the Spanish Government passed an Act (Real Decreto 1215/1985, dated on 17th of July, 1985) that established a tariff on headings 84.52 (calculator and accounting machines, cash registers, etc.) and 84.53 ("automatic machines for data processing", including computers) imported from foreing countries.
2. Foreing computer manufacturers lobbyed themselves as a response, and forced the Government to move to an equidistant position: the tariff would be charged only on "micro-computers", that is, "automatic machines for data processing with less than 64 KB of memory". The lobbying movement was so effective that the Spanish Ministro de Economía (equivalent to the head of the British Departments of Commerce and Treasury), Carlos Solchaga, gave up his summer vacation and travelled to Mallorca, were the king was having his holidays, to have the new law signed (Real Decreto 1558/1985, dated on 28th of August, 1985). The urgency of the trip gives an idea of how powerful were foreign computer manufacturers at that time.
3. The tariff charged on imported computers lasted one month only, from the 25th of July to the 3rd of September, 1985. The amount of the tariff per unit ranged from 15,000 to 300,000 pesetas (90 to 1,800 euro at current prices), depending on the type and the value of each particular model. From the 3rd of September, 1985, only computers with less than 64 KB of RAM were charged with the 15,000ptas./90€ tariff, leaving tax-exempt the rest.
4. Amstrad España wasn't fully satisfied by the tariff discount, and started selling their allegedly 72 KB model (Amstrad CPC 472) on September 1985 to avoid the tariff. My guess is that Amstrad UK was aware of this movement (maybe not his engineers, but at least the sales department), since the computers should arrive at Spain with the legend "72 KB RAM computer" labelled anyplace.
5. Spain joined the EEC on 1st of January, 1986. The Government had to align his tariffs policy with that of the EEC, and as a result it has to remove the charges on the heading 84.53 (EEC Comission Decision 1985/80908, dated on 15th of November, 1985). There was no point in marketing the CPC 472 model from then on.
*One of them may have been Eurohard, the Spanish company that bought the rights on the Dragon range of computers to Dragon Data at the end of 1984. Eurohard was manufacturing and selling 32 KB and 64 KB computers at that time -the Dragon 32, Dragon 64 & Dragon 200 models-, and developing a MSX-1 compatible computer with no more than 64 KB of RAM.
Hi deepfb, thanks for the info! I wasn't aware of the lobbying part. Silly me, could have imagined that the capital dictated what happens in politics :-)
Now, I have missed the part where the spanish keyboard came in. Wasn't that important for paying / not paying the tax, too?
And in the end, after 1st Jan 1986, the tax was completely dropped, and neither 72K nor the N~key were required?
>"15,000 to 300,000 pesetas (90 to 1,800 euro at current prices)"
Good to know. Definetly more than the cost of the daughterboard.
Silly me, could have imagined that the capital dictated what happens in politics :-)
That is always true :-D
Now, I have missed the part where the spanish keyboard came in. Wasn't that important for paying / not paying the tax, too?
Making the spanish keyboard compulsory for every home computer is not related at all with the marketing of the 472 model. I believe the confussion comes from the coincidence in time of the Acts setting the new tariffs (RD 1215/1985 and RD 1558/1985) and the Acts that made compulsory the inclusion of the Ñ key (RD 1250/1985 and RD 2707/1985).
And in the end, after 1st Jan 1986, the tax was completely dropped, and neither 72K nor the N~key were required?
No, being an EEC member only affected to the tariffs policy, so only the tax was dropped. The obligation of marketing computers with a spanish keyboard is still valid, as it is also in France, Germany or Belgium with french, german or belgian keyboards, if I'm not wrong.
It's true that making compulsory to sell a particular, language-specific keyboard can be seen as an anti-free trade regulation, but at the end the EEC allowed this kind of national regulations in order to preserve the cultural heritage of each country.
Whew, two different laws. Can we copy that info to the 472 page... or did you plan to add it yourself?
Don't think we had (or still have) a law for german keyboards. The CPCs all had english keyboards, some MSXs had english, some had german keys. German keys became standard with PC keyboards, but that might have been self-regulated; it' would just have looked strange if common PC users (like office people) would write letters without umlauts.
Btw. how usable was the spanish CPC keyboard in practice? It has the tilded N, but still lacks topdown ? and ! and the turkish C. And didn't have (or did it?) dead keys for accent marks on áéí.. and àèì.. and âêî.. Guess some of them might be almost more important than the N... though that comes in "espanol" so maybe somebody insisted that it'd need priority :-)
Quote from: ukmarkh on 11:43, 14 April 10
Alan Sugars new book, your fired! Talks about Amstrad's history in great detail. Worth picking up.
Really? Had no idea!!! Darn, my last Amazon order was delivered a few days ago... I'm picking it up indeed.
Whew, two different laws. Can we copy that info to the 472 page... or did you plan to add it yourself?
Well, although cpcmaniaco has explained me several times how to add contents to the wiki, I'm too lazy -and I'm little bit too busy- to do it myself. So I would be very grateful if you place it on the proper article :-)
Btw. how usable was the spanish CPC keyboard in practice? It has the tilded N, but still lacks topdown ? and ! and the turkish C. And didn't have (or did it?) dead keys for accent marks on áéí.. and àèì.. and âêî.. Guess some of them might be almost more important than the N... though that comes in "espanol" so maybe somebody insisted that it'd need priority :-)
Circumflex accents (â, ê, î...) are not present in spanish, and cedilla (Ç) and grave accents (à, è, ì...) are not used at all in spanish, galego or euskera, but in catalan only -catalan speakers will also miss one letter only present in their language, the 'geminada' l, which is like this: l·l - for example, col·lateral ('collateral' in english), or il·legal ('ilegal' in english).
So as a castellano-speaking, when using the Amstrad CPC I'm lacking of the usual accents (á, é, í...), opening exclamation and question marks (¡ ¿) and diaeresis (in castellano-spanish, only over the ü, and not very commonly used).
Only the lack of accents is a real problem, but I think there was some word processor(s) that addressed the `\ key to a specifically-created character, so accented vocals could be displayed on the monitor, and even printed. Does any spanish user remember that, or am I wrong?
Anyway, I haven't ever thought about it: is it annoying to write texts on a CPC for german or french people? (I'm sure it is for greek, turkish or danish users ...not to say the Aleste owners :-D).
Quote from: deepfb on 21:12, 14 April 10
is it annoying to write texts on a CPC for german or french people?
No, but they do tend to have some symbols transferred to the front of a few keys (for their umlauts and sz ligature), as on http://cpcwiki.eu/forum/index.php?action=dlattach;topic=662.0;attach=452;image.
PC keyboards additionally swapped Y and Z (and make it a little hard to enter c-cedilla except by Alt-135 or on Linux) for the German layout, but the French one is very different indeed (as sold there on the CPC already).