Oscillator design is one of the parts of electronics that is considered a black science!
Mark
ZX81 rebuild
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1024MAK
- Posts: 5332
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: ZX81 rebuild
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
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Lardo Boffin
- Posts: 2235
- Joined: Sat Nov 26, 2016 2:42 am
Re: ZX81 rebuild
Oh good. At least it is an easy one to sort then.
Maybe one of these?
https://www.cricklewoodelectronics.com/SFE6M5.html
Not much detail on their site though.
Maybe one of these?
https://www.cricklewoodelectronics.com/SFE6M5.html
Not much detail on their site though.
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
-
1024MAK
- Posts: 5332
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: ZX81 rebuild
Other 'black arts' in electronics include switch-mode power supply systems and boost and buck DC-DC converters... (well, before special 'easy to use' chip came on the market).
As to which is the most suitable ceramic resonator, it's a case of buy it and try it as far as I can tell. The normal use of these is as part of a filter circuit, not as oscillators.
Mark
As to which is the most suitable ceramic resonator, it's a case of buy it and try it as far as I can tell. The normal use of these is as part of a filter circuit, not as oscillators.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
Re: ZX81 rebuild
Lardo PokeMon has them on S.M.R.Lardo Boffin wrote: ↑Tue Feb 06, 2018 7:53 pm Oh good. At least it is an easy one to sort then.
Maybe one of these?
https://www.cricklewoodelectronics.com/SFE6M5.html
Not much detail on their site though.
https://www.sellmyretro.com/offer/details/3469
Brian
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Lardo Boffin
- Posts: 2235
- Joined: Sat Nov 26, 2016 2:42 am
Re: ZX81 rebuild
Thanks!
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
-
Lardo Boffin
- Posts: 2235
- Joined: Sat Nov 26, 2016 2:42 am
Re: ZX81 rebuild
Well, after a brief pause to move house (if only the builders had finished it before we moved in 
) I have finally got back to this!
I fitted a turned pin socket for the oscillator and put in an original zeddy one:-
Its alive!!!
And yes I have been relegated to the garage. Something to do with melting holes in worksurfaces...
Bouyed up by this I fitted a new one from Sell My Retro and....
Still alive! I have a new ROM and hopefully a new ULA from Andy at some point at which time the only original component will be the PCB and case. Hmmmm....
) I have finally got back to this!I fitted a turned pin socket for the oscillator and put in an original zeddy one:-
Its alive!!!
And yes I have been relegated to the garage. Something to do with melting holes in worksurfaces...
Still alive! I have a new ROM and hopefully a new ULA from Andy at some point at which time the only original component will be the PCB and case. Hmmmm....
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
-
1024MAK
- Posts: 5332
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: ZX81 rebuild
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Autumn is here. Bye bye summer 2024...
well done, well done -
Lardo Boffin
- Posts: 2235
- Joined: Sat Nov 26, 2016 2:42 am
Re: ZX81 rebuild
Thanks. One of your ROMs will be going into it!
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
Re: ZX81 rebuild
Hopefully not the X2 ROM (it's packed with C-4 and a certain keypress combination sets it off)
Apologies it's whisky night.