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Re: Lardo buys another zeddy

Posted: Thu May 20, 2021 9:16 pm
by Lardo Boffin
Moggy wrote: Thu May 20, 2021 6:41 pm OY Norma's my wife you mean sod!! :lol:
You married the lady in the photo?
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Re: Lardo buys another zeddy

Posted: Thu May 20, 2021 9:33 pm
by Moggy
Christ no Lardo I was only joking, don't tell out lass what ever you do or I will be a castrated Tabby! :lol:

Re: Lardo buys another zeddy

Posted: Fri Jun 04, 2021 2:25 pm
by Lardo Boffin
A very nice boxed issue three with RAM pack and learning lab. All working (but not tested the learning lab)!

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Re: Lardo buys another zeddy

Posted: Fri Jun 04, 2021 2:52 pm
by Moggy
Nice Lardo.

I have a soft spot for those Stonechip memory packs, more reliable than Clive's offerings in my opinion.
They use a different memory chip to the Sinclairs(Mark will know which ones) and if you pop the back cover off (clip on on not screwed) there should be a set of clips that take a 16k module which takes the pack up to 32k, though I never saw or got my hands on one sorry to say.

Re: Lardo buys another zeddy

Posted: Fri Jun 04, 2021 3:32 pm
by 1024MAK
Moggy wrote: Fri Jun 04, 2021 2:52 pm I have a soft spot for those Stonechip memory packs, more reliable than Clive's offerings in my opinion.
They use a different memory chip to the Sinclairs(Mark will know which ones) and if you pop the back cover off (clip on on not screwed) there should be a set of clips that take a 16k module which takes the pack up to 32k, though I never saw or got my hands on one sorry to say.
Yes, there is provision inside for an extra board to increase the capacity. I can’t remember which actual DRAM chips these use (will have to find mine later), but there are as far as I know, only three common types of DRAM chip that easily provide 16k bytes. Although there are many variations of some of these.
  • 16k x 1 bit types like MK4116P-2, TMS4116, uPD416, 4116 etc, (all of which need the three different supply voltages).
  • 16k x 1 bit types like HM4816, MOSTEK MK4516N, Fujitsu MB8118-10 (single +5V supply types).
  • 16k x 4 bit types like TMS4416 etc.
Mark

Re: Lardo buys another zeddy

Posted: Fri Jun 04, 2021 4:48 pm
by Lardo Boffin
Moggy wrote: Fri Jun 04, 2021 2:52 pm Nice Lardo.

I have a soft spot for those Stonechip memory packs, more reliable than Clive's offerings in my opinion.
Having not seen one before I have had two of these in an many weeks! Like buses. :)

Re: Lardo buys another zeddy

Posted: Fri Jun 04, 2021 5:27 pm
by Lardo Boffin
Some photos of the inside here viewtopic.php?p=43130#p43130

Re: Lardo buys another zeddy

Posted: Fri Jun 04, 2021 6:47 pm
by 1024MAK
Of course it had to be the National Semiconductor MM5290N-2 that I did not list :lol:

These are similar to the 4116 DRAM chips in that they also need three separate supply voltages.

Mark

Re: Lardo buys another zeddy

Posted: Fri Oct 08, 2021 2:51 pm
by Lardo Boffin
Well, its been a while but clearly the therapy has not worked…

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A fairly nice issue one, working, with some very nice books. I don’t think I had any for the ZX80.

As suspected from the soft spongy feet it is a fairly early one, ROM 550 so bugged for maths.

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Re: Lardo buys another zeddy

Posted: Fri Oct 08, 2021 3:26 pm
by Moggy
Lardo Boffin wrote: Fri Oct 08, 2021 2:51 pm Well, its been a while but clearly the therapy has not worked…


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A fairly nice issue one, working, with some very nice books. I don’t think I had any for the ZX80.

As suspected from the soft spongy feet it is a fairly early one, ROM 550 so bugged for maths.


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Ram chips socketed so looks like it could be a kit build.
I believe the ZX80 companion book is a bit of an holy grail. some 12 years have passed since someone wondered if it was ok to post a scan of it though it never came to pass.