16K RAM Pack photos - please add yours

Discussions about Sinclair ZX80 and ZX81 Hardware
Lardo Boffin
Posts: 2155
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)
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
bola_dor
Posts: 398
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 USA, ZX81UK, ZX Spectrum, ZX Spectrum+, ZX Spectrum 128+ UK, ZX Spectrum +2/A, Sinclair QL, CZ1000, CZ1500, CZ2000, CZ1000Plus, CZ1500Plus, CZ Spectrum, CZ Spectrum Plus, TK83, TK85, TK90X, TK95. TS2068. And more to come :D
Lardo Boffin
Posts: 2155
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)
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
bola_dor
Posts: 398
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 USA, ZX81UK, ZX Spectrum, ZX Spectrum+, ZX Spectrum 128+ UK, ZX Spectrum +2/A, Sinclair QL, CZ1000, CZ1500, CZ2000, CZ1000Plus, CZ1500Plus, CZ Spectrum, CZ Spectrum Plus, TK83, TK85, TK90X, TK95. TS2068. And more to come :D
jsweinrich
Posts: 16
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: 337
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: 398
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 USA, ZX81UK, ZX Spectrum, ZX Spectrum+, ZX Spectrum 128+ UK, ZX Spectrum +2/A, Sinclair QL, CZ1000, CZ1500, CZ2000, CZ1000Plus, CZ1500Plus, CZ Spectrum, CZ Spectrum Plus, TK83, TK85, TK90X, TK95. TS2068. And more to come :D
Lardo Boffin
Posts: 2155
Joined: Sat Nov 26, 2016 2:42 am

Re: 16K RAM Pack photos - please add yours

Post by Lardo Boffin »

A SPECIAL RAMPACK by Audio Computers:

74B2AAEF-5504-40B3-BC80-EA2E5E34F399.jpeg
72F01C5F-DC79-4B4C-9B53-46144F468B47.jpeg
94CE449D-CB45-4B90-A479-470F5C12605C.jpeg

Although the board suggests it made by Solidisk. :lol:

I wonder what goes in the socket?
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
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XavSnap
Posts: 1940
Joined: Sat May 10, 2008 4:23 pm
Location: 'Zx81 France' Fb group.

Re: 16K RAM Pack photos - please add yours

Post by XavSnap »

Seem to be a STL like card:
http://zx81.ordi5.free.fr/CartesZx81/STL/

A buzzer ?
121482839_10224317789309493_2615623835026072474_o[1].jpg
Xavier ...on the Facebook groupe : "Zx81 France"(fr)
Lardo Boffin
Posts: 2155
Joined: Sat Nov 26, 2016 2:42 am

Re: 16K RAM Pack photos - please add yours

Post by Lardo Boffin »

Interesting! The boards are pretty much identical apart from the green wire from the edge connector being replaced with a resistor and not having the buzzer attached.

I wonder if the buzzer requires the EPROM or just a buzzer to be physically connected?
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
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