Re: 16K RAM Pack photos
Posted: Fri Jun 04, 2021 5:27 pm
And a Stonechip Panda 16K RAM pack:
Close up of RAM chip:
Close up of RAM chip:
Discussion forums for users of the Sinclair 8-bit range of computers - ZX80, ZX81, ZX Spectrum, Z88, clones...
https://www.sinclairzxworld.com/
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,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
Can you add some photos if you any please?bola_dor wrote: ↑Sat Jun 05, 2021 5:42 amMicrodigital 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,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
Later I ll take some. But I am talking about twhe main board RAM not the packs.. those are 16KB TS1500 clones