16K RAM Pack photos - please add yours

Discussions about Sinclair ZX80 and ZX81 Hardware
Lardo Boffin
Posts: 1487
Joined: Sat Nov 26, 2016 2:42 am

Re: 16K RAM Pack photos

Post by Lardo Boffin »

And a Stonechip Panda 16K RAM pack:

018E6CAB-E44A-4267-8781-D4FF3C449749.jpeg

Close up of RAM chip:
499DB884-7A93-4DBE-90B2-E18A221D087E.jpeg
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Toastrack
bola_dor
Posts: 277
Joined: Wed Oct 02, 2019 5:32 am

Re: JRS 16K RAM Pack

Post by bola_dor »

1024MAK wrote: Thu Oct 24, 2019 5:19 pm This is about the sixth design of ZX81 RAM pack that I have seen. Each one uses a different method or different variation of design for obtaining a -5V supply. Some use a transistor oscillator driving an inductor like the Sinclair 16k RAM pack. Some use a CMOS logic chip and capacitors to do it. Some use an audio amplifier chip. IIRC, I think I have seen one using a NE555.


Mark
Microdigital and TK90X-A (Argentinian market versions at least) uses NE555 to make -5v and CZ Spectrum/Plus uses NE555 to make 12v. On the main board as all those are 16KB,
Ernesto
ZX80, TK83, CZ1000, CZ1500, TK85, CZ2000, CZ1000Plus, CZ Spectrum, TK90X 16Kb, CZ Spectrum Plus, TS2068, Sinclair QL. TS 1016, TS1040. And more to come :D
Lardo Boffin
Posts: 1487
Joined: Sat Nov 26, 2016 2:42 am

Re: JRS 16K RAM Pack

Post by Lardo Boffin »

bola_dor wrote: Sat Jun 05, 2021 5:42 am
1024MAK wrote: Thu Oct 24, 2019 5:19 pm This is about the sixth design of ZX81 RAM pack that I have seen. Each one uses a different method or different variation of design for obtaining a -5V supply. Some use a transistor oscillator driving an inductor like the Sinclair 16k RAM pack. Some use a CMOS logic chip and capacitors to do it. Some use an audio amplifier chip. IIRC, I think I have seen one using a NE555.


Mark
Microdigital and TK90X-A (Argentinian market versions at least) uses NE555 to make -5v and CZ Spectrum/Plus uses NE555 to make 12v. On the main board as all those are 16KB,
Can you add some photos if you any please?
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
Iss 3 ZXVid
TS 1000 iss 3, ZXPand AY, ZX8-CCB, ZX-KDLX & ChromaSCART
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Toastrack
bola_dor
Posts: 277
Joined: Wed Oct 02, 2019 5:32 am

Re: JRS 16K RAM Pack

Post by bola_dor »

Lardo Boffin wrote: Sat Jun 05, 2021 11:43 am

Can you add some photos if you any please?
Later I ll take some. But I am talking about twhe main board RAM not the packs.. those are 16KB TS1500 clones
Ernesto
ZX80, TK83, CZ1000, CZ1500, TK85, CZ2000, CZ1000Plus, CZ Spectrum, TK90X 16Kb, CZ Spectrum Plus, TS2068, Sinclair QL. TS 1016, TS1040. And more to come :D
jsweinrich
Posts: 8
Joined: Mon May 31, 2021 6:22 pm

Re: 16K RAM Pack photos - please add yours

Post by jsweinrich »

I went with a perf board using wire wrap to connect it all. Flat cable from ZX81 edge connector to the perf board. Perf board also has I/O. SRAM is actually 32kx8 (MT5C2568-30).
20210601_115943s.jpg
20210601_120144s.jpg
McKlaud
Posts: 315
Joined: Tue Dec 19, 2017 10:02 pm
Location: St Albans, UK

Re: 16K RAM Pack photos - please add yours

Post by McKlaud »

I did a tiny board with SMD components.

Image
Claudius
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bola_dor
Posts: 277
Joined: Wed Oct 02, 2019 5:32 am

Re: 16K RAM Pack photos - please add yours

Post by bola_dor »

This I picked up from the trash. Sold as Czerweny CZ1016, argentina, 99.99% Timex Portugal hardware but note the transistor..
20210625_002403.jpg
2021-6-25 0-27-19.jpg
Ernesto
ZX80, TK83, CZ1000, CZ1500, TK85, CZ2000, CZ1000Plus, CZ Spectrum, TK90X 16Kb, CZ Spectrum Plus, TS2068, Sinclair QL. TS 1016, TS1040. And more to come :D
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