Sinclair ZX80 / ZX81 / Z88 Forums

Agreed speculation , any Timex Dundee or Ferranti workers amongst us?
A lot of questions about so many things could be answered, but like many things in life, when you work with it all day the chances are you don't want it for a hobby so unlikely to be forum members which is a pity.

Not sure about the returns thing as mine was a very early mail order jobby so should have been a directly soldered board not socketed like the later ones, so I think maybe too early for a returned 81 but as you say Mark quite possible.

In my post above, I was mainly talking about the cassette leads...

I'm not sure what to make of the soldered ULA / socketed ULA thing with the first Zeddies.

I never had a Zeddy when they first came out, so have no personal experience from that time about the insides (I just played with the ones in the shops until I got shooed out ).

In more recent times, thanks to ebay and car boot sales, I have bought more Zeddies, so now I have more Zeddies than I care to count (having got more second hand Zeddies working than I expected from "faulty" / "unable to test" / "not working" / "no TV to test on" sales etc.). So without trying, I have a mixture of issue 1 boards (and issue 3 boards) with socketed ULA's and a couple of issue one boards that have the early ULA, but which are soldered to the board.

Logically, I would have thought that Sinclair would have soldered all the chips in order to keep the cost down. But as we all know, this did not happen.
Maybe some of the returned ZX81's changed the Sinclair policy? And the reliability (or lack of) some of the chips resulted in the chips that were more likely to fail being socketed? But that does not explain the ROM (mask ROM chips are normally very reliable).

Having gone and said all that, the issue one ZX Spectrum that I have, only has the ROM in a socket. Everything else is soldered including the ULA...

So maybe at one point, sending out replacement ROM's was considered likely...

Would be nice to find out the reasons. But I suspect we will never find out

Mark

Don't forget to throw the self-build ZX81s into the mix as well - as they were available as a kit, as were the early ZX80s (back on thread)....

Moggy: I bought this Zeddy back in 2003 (was my first ever eBay purchase!), were you selling then? It has an early looking RF cable that's almost like the one pictured by the OP, but with a black plug with white retaining ring on the TV side. It's boxed and complete (even included the 16K RAM pack instruction sheet).

Here's a pic of the leads in question, the datecode on the ULA of this one is 8130, so not an overly early model. Don't think it was a kit judging by the soldering quality.



(Ahem). Right, back on topic, sorry That's a cracking ZX80 you have and you should have no trouble selling it as is. Best of luck!

B

balford wrote:Moggy: I bought this Zeddy back in 2003 (was my first ever eBay purchase!), were you selling then? It has an early looking RF cable that's almost like the one pictured by the OP, but with a black plug with white retaining ring on the TV side. It's boxed and complete (even included the 16K RAM pack instruction sheet).

Here's a pic of the leads in question, the datecode on the ULA of this one is 8130, so not an overly early model. Don't think it was a kit judging by the soldering quality.



(Ahem). Right, back on topic, sorry That's a cracking ZX80 you have and you should have no trouble selling it as is. Best of luck!

B

I had been buying and selling Sinclair stuff since the seventies (Hi-Fi stuff initially) the speccy I never bothered with as it was too unreliable (six returned in one afternoon so customer bought an Oric)and a bit of a liability from my point of view though oddly enough I use one with an EPROM burner for burning the older 25v EPROMS, nowadays I'm more of a user.

The black plug-yellow tag leads I have always associated with ZX80's, the first ones I came across at the time had these same MIC/EAR leads. I am also coming round to Marks way of thinking that being the tight wad he was Uncle Clive would not throw old stock away so for the 81 I now believe that some early ones may have indeed come with the older style lead before switching to the familiar black/grey moulded plug leads that I first saw with the issue three boards, and seeing how some ZX80's were built at Timex Dundee that would make sense.

I still have a few of the RF cables you describe and have never personally seen them with anything other than the early "margarine tub plastic" ZX80's assembled by Tek electronics in St Ives, though again for the reasons mentioned above I'm willing to concede that early 81's may have used this same RF lead also.

As for the OP's ZX80 I hope that if it is malfunctioning He gets back to us as it would be nice for an old timer to be back on the road in a working condition.

Moggy wrote: I had been buying and selling Sinclair stuff since the seventies (Hi-Fi stuff initially) the speccy I never bothered with as it was too unreliable (six returned in one afternoon so customer bought an Oric)and a bit of a liability from my point of view though oddly enough I use one with an EPROM burner for burning the older 25v EPROMS, nowadays I'm more of a user.

Apologies Moggy, I had no idea you had that depth and longevity of experience

B

No apologies needed Balford My friend.

The only reason I gained any knowledge and experience at the time was purely fiscally motivated, the games era I was a bit too old for so those discussions as such tend to go over my head , I also sold and repaired power tools and light plant during the day and twanged my banjo at night to pay the mortgage.

The reason I love the 81 is that in many ways it represents the bridge between modern computing (VDU touch screen/membrane etc)
yet retains the old bucket of bolts-can-be tinkered-with philosophy of the Ferrantis ,IBMs and other electronic brains that were making their mark and left me wide eyed in wonderment when I was a nipper.

As I have become more interested over the years as a user I freely admit I would give my left arm for just a tenth of the knowledge and understanding you lads have about all things Sinclair, the code writers amongst you leave me open mouthed in admiration plus the hardware threads of this and the WOS forum and all your musings give me more pleasure than you can ever know and I sincerely thank you all for it.

Thank you everyone for the advice.

I just listed it for sale on this site now. I never did get a cursor, even using an onld TV. It's outputting a signal, but I couldn't tune it to show a cursor even with a nice old B&W analogue tune TV.

I realise that this will affect the price, but I'm going to leave it to some expert to work it out (if they wish to). I'm sure it now deserves a home without someone who can give it a better life than it's had for 30 years in a cupboard.

The link to the auction is: http://www.sellmyretro.com/offer/detail ... puter-4182