"Different" ZX81's
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Lardo Boffin
- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: "Different" ZX81's
Looks like I may have sparked another debate!
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
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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1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: "Different" ZX81's
No big debate, the logo is used on some Spectrum ULAs, where the Spectrum is a standard UK board.
This website shows the logo.
I suspect the printing (or not) of the logo may depend on the actual fab that made the ULA and maybe even be down to the batch that was produced. You sometimes see this with other manufacturers, where the same chip has different markings compared to chips produced in another fab.
Oh, and please keep your sparks away from our Zeddies
Mark
This website shows the logo.
I suspect the printing (or not) of the logo may depend on the actual fab that made the ULA and maybe even be down to the batch that was produced. You sometimes see this with other manufacturers, where the same chip has different markings compared to chips produced in another fab.
Oh, and please keep your sparks away from our Zeddies
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.
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.
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RetroTechie
- Posts: 379
- Joined: Tue Nov 01, 2011 12:16 am
- Location: Hengelo, NL
- Contact:
Re: "Different" ZX81's
This (short!) Wikipedia article explains it all: Zetex Semiconductors
Logo found on this Tweakers.net electronics-related page: Manufacturers of ICs and their logos
Must say, one bl**dy hard to find logo when it comes to IC manufacturers!
(and I've seen quite a few in my life 
)
Logo found on this Tweakers.net electronics-related page: Manufacturers of ICs and their logos
Must say, one bl**dy hard to find logo when it comes to IC manufacturers!
(and I've seen quite a few in my life )Re: "Different" ZX81's
@ Retro Techie.
Great information there as always many thanks for that.
@ Lardo
keep sparking, it helps to increase this idiots knowledge
@Mark
Thanks for spoiling my bloody fun,I was going to dedicate the next 10 years to finding that sodding logo!!
No seriously,concise and well explained as always,cheers Mark.
Great information there as always many thanks for that.
@ Lardo
keep sparking, it helps to increase this idiots knowledge
@Mark
Thanks for spoiling my bloody fun,I was going to dedicate the next 10 years to finding that sodding logo!!
No seriously,concise and well explained as always,cheers Mark.
Re: "Different" ZX81's
As we are talking ULA's, seeing this pair makes me think that the 2c210e was introduced roughly week 21/22 of 1982
ZX80, ZX81 - 2C158C Bugged Rom iss.1, 2C158C "kludge fix" iss1, 2C184E iss1, 2C210E iss3, US NTSC iss1 "straight traces", US NTSC iss3 TS1000
Re: "Different" ZX81's
Well deduced that man!!
Re: "Different" ZX81's
Longtime lurker Shortime poster lol
What have i got here cannot find any info on gold zx81 64k chips lol
What have i got here cannot find any info on gold zx81 64k chips lol
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Re: "Different" ZX81's
Ooh nice!
Sinclair had a shortage of the normal ROM's so had to use these eproms for a while. They seem to be in Issue 3's mostly, but I do have one in an Issue 1 board.
Neither of my two have a nice shiny gold eprom though - lovely!
Sinclair had a shortage of the normal ROM's so had to use these eproms for a while. They seem to be in Issue 3's mostly, but I do have one in an Issue 1 board.
Neither of my two have a nice shiny gold eprom though - lovely!
ZX80, ZX81 - 2C158C Bugged Rom iss.1, 2C158C "kludge fix" iss1, 2C184E iss1, 2C210E iss3, US NTSC iss1 "straight traces", US NTSC iss3 TS1000
Re: "Different" ZX81's
i have a couple like that, same type eprom, 2564
Re: "Different" ZX81's
Thanks ive got a couple of type three boards but nothing like this is the 64k normal too? It looks very factory with the bodge wires
just ordered some keyboards to get them working also i think the ula is dead on one
i bought a job lot back in the late1990s got some odd expansion modules too it there a thread for unusual expansions ?
regards
Mike
just ordered some keyboards to get them working also i think the ula is dead on one
i bought a job lot back in the late1990s got some odd expansion modules too it there a thread for unusual expansions ?
regards
Mike