Lardo buys another zeddy

ZX80 / ZX81 hardware and software offered for sale or swapping
Lardo Boffin
Posts: 2155
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post 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?
171EA909-53A7-4A0F-B251-493B2CCD2A6D.jpeg
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Moggy
Posts: 3222
Joined: Wed Jun 18, 2008 2:00 pm

Re: Lardo buys another zeddy

Post 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:
Lardo Boffin
Posts: 2155
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post by Lardo Boffin »

A very nice boxed issue three with RAM pack and learning lab. All working (but not tested the learning lab)!

7479D335-916C-495A-B1F8-B87777808093.jpeg
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Moggy
Posts: 3222
Joined: Wed Jun 18, 2008 2:00 pm

Re: Lardo buys another zeddy

Post 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.
User avatar
1024MAK
Posts: 5087
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Lardo buys another zeddy

Post 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
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
Lardo Boffin
Posts: 2155
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post 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. :)
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Lardo Boffin
Posts: 2155
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post by Lardo Boffin »

Some photos of the inside here viewtopic.php?p=43130#p43130
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
User avatar
1024MAK
Posts: 5087
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Lardo buys another zeddy

Post 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
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
Lardo Boffin
Posts: 2155
Joined: Sat Nov 26, 2016 2:42 am

Re: Lardo buys another zeddy

Post by Lardo Boffin »

Well, its been a while but clearly the therapy has not worked…

A1B521FD-6696-4677-9991-EC36A7B6DFA1.jpeg

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.

08D026F6-D309-4588-8DDD-CA65183AB2C4.jpeg
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Moggy
Posts: 3222
Joined: Wed Jun 18, 2008 2:00 pm

Re: Lardo buys another zeddy

Post by Moggy »

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


A1B521FD-6696-4677-9991-EC36A7B6DFA1.jpeg


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.


08D026F6-D309-4588-8DDD-CA65183AB2C4.jpeg

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.
Post Reply