Remanufactured ULAs?

[Spirantho]

Hi everybody,

I see Ian's listed another 60-odd ULAs on eBay....

There's nothing wrong with that (in fact, it's good of him not to whack the price up!) but WHERE are these coming from?
A few years back I did a few searches for chips like this - things like SID chips, MOS 8501 chips, and of course Spectrum and ZX81 ULAs.
Nothing came up, not terribly surprisingly.

Then all of a sudden the Retro Computer Shack list 77 of the blighters. Where do they come from? Maybe a hidden stash...

... so I go off hunting. I did a quick search on DigChip for 2C210E and sure enough there it is: stock levels: 10,000+
I asked for a quote, and got no less than three replies, each offering over 100 of them. One seller was $8ea for 100, $10ea for 10, the other was $12ea, the other $25ea.

Call me a cynic, but I find it very unlikely that in 1983, when Uncle Clive was winding down production of the ZX81 which was by then being offered cheap on the High Street (I know, because I bought my Zeddy then for £45 from WH Smiths with a RAM pack and Invasion Force - happy days ), he would have placed an order for 10s of thousands of them! And if he did, why were they not used? The ones in the picture on Ian's eBay listing are dated 8312 which is correct but rather late for a ZX81 ULA.

So where do people think these come from? How come so many Chinese suppliers suddenly have stacks of them? I'm wondering if someone somewhere has reverse engineered the ULA (I believe it's quite well documented now) and tooled up a fabrication plant to create them on demand.

I ordered 10 of the $10 ones. The lead time was 1 week. I wonder if this is how long it takes for them to arrive by Chinese post, or whether this is how long it takes to manufacture them!

They should be being shipped out in the next day by courier, so I should get them soon. If people are interested, I'll be more than happy to share my experiences of it.

Incidentally, I don't really care if they are re-manufacturing them. In fact, I hope they are! ZX81 ULAs on demand - for the win!

[RWAP]

It does seem possible - but I do wonder what the chinese would want to do with the ZX81 ULA... Maybe they are used in something else - powering the new Chinese power stations for example....

Mind, I do remember a rumour at the time that the Russians had purchased a pile of ZX81s as a nice very light computer - just ideal to fit inside the head of an ICBM and powerful enough to enable it to hit the western world....

[mcleod_ideafix]

so I go off hunting. I did a quick search on DigChip for 2C210E and sure enough there it is: stock levels: 10,000+

Well, that's weird.

The Ferranti ULA 2C210E is a custom chip that needs the customer to provide the metalization layer in order to "personalize" the chip. The Spectrum uses a Ferranti ULA too, but according to Chris, this seemed to be a special issue of the ULA just for Sinclair. I assume that earlier computers, like the ZX81 used a stock ULA.

What I mean is that if you would find a stock of Ferranti ULA 6C001E-6, for example, you can be sure that those ULA's have been customized for Sinclair and are in fact, ZX Spectrum ULA's. But if you find a stock of 2C210E ULA's, nothing can asure you that inside those ULAs the Sinclair design is present. Ferranti had to have dozens or hundreds of customers, and maybe that apart from Sinclair, another customer did use the model 2C210E.... or maybe not?

Or... was Ferranti a fabless semiconductor company? Then it could be possible that the chip itself was manufactured in China and they still keep a pile of them.

[PokeMon]

In my eyes the naming 2C210E describes the customer program of that chip and is not an empty (unprogrammed) type.
Nobody would produce a black box without printing it's content on it.
Why do you think 2C210E would be just a general type ?
I think there is not really a difference to the 2C184 (without backporch).
I think it's the same hardware type with just another custom program/mask.

Maybe "2C" is a ULA type/size and 210 is the customized program/mask (like 184 before).

[gozzo]

'Pokemon' is pretty much right! You really need to read the book 'The ZX Spectrum ULA' by Chris Smith as although this is primarily about the speccy ULA, this explains it all, but just to give the quick details, the first '2' indicates the particular 'array' type/number of logic cells; the 'C' indicates 'very high speed - 20Mhz max,8ns gate delay,210uA gate current,and CML (current mode logic); the '210' is the particular 'customisation', in other words it specifies its a ZX81 ULA(with back porch )!; and the 'E' is for 'plastic DIL package' !

[gozzo]

There's always a nasty possibility that those Chinese 2C210E's are nothing to do with the ZX81 ULA and a totally different thing!

[PokeMon]

The Chinese list the typo 2C210E and the manufacturer Ferranti.

ferranti.jpg (30.54 KiB) Viewed 7126 times

[1024MAK]

Well, it won't be the first time that there has been two completely different chips / integrated circuits with very similar / the same type numbers...

Or it could be simply a box of say 500, that has been found and companies are being creative with their stock numbers in the hope that they will attract orders, and they think if there is lots of interest, they can source more stock... ( so they think!!!)

Or someone has a time machine!

Mark

[Spirantho]

Those are the ones I've ordered.
I'm taking a risk by ordering $100 of apparent ULAs so I'd recommend nobody else ordering any till I've got mine. No point in more people risking their cash... I just figure if the gamble pays off it'll help us all!

[1024MAK]

Hang about, which year in the 80's was the year that caught out all the 8 bit computer manufacturers?
The year where Christmas sales were a lot less than expected. So lots of companies found they had piles of unsold computers, lots of stock on order that would soon have to be paid for, and which it was not cost effective to cancel at short notice?
Did Sinclair fall into this trap with the Zeddy as well as the Speccy?

Mark