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-   -   Sinclair ZX Spectrums. (https://www.vintage-radio.net/forum/showthread.php?t=157450)

ViperSan 21st Jun 2019 10:50 am

Sinclair ZX Spectrums.
 
2 Attachment(s)
I recently restored 2 48K spectrums ..
One of which required extensive trace repair and was actually only a 16K machine..so more ram fitted.
This one was earmarked for a case with a proper keyboard.
..and because the case had space for mods ..
A dual rom with a rear switch allows for standard or gosh wonderfull at boot.
It also has a rear power switch ..and reset button.
I then canabalised a TV for its pcmcia slot runners ...and these were top mounted so that a ZXDuino unit could be slid in...thus eliminating the need for tape loading.
I guess this is my go to machine now.
The second unit is restored as it should be..
having a restored case and new membrane for the rubber keyboard.
I had to have one in original condition didn't I
lol
anyhoo ..
here are both machines side by side (a sort of before and after)
rgds
VS
btw I have a few days of freedom as my elderly mum with dementia is in respite.
So if anyone wants to see my Apple IIs or any commodore computers (including the PET) I have a few days to do this.

Timbucus 25th Jun 2019 8:21 pm

Re: Sinclair ZX Spectrums.
 
Nice combination the low profile version mounting a ZXDuino - I have never used one as I went straight to DivMMC devices. Glad to see two more preserved for the future especially saving the boards with a trace repair that is dedicated. What version PCB were they - I have two Issue 2 left in my pile that have faults that are driving me crazy, I will eventually find them it will be a short somewhere or a passive as it is intermittent!

ViperSan 25th Jun 2019 8:36 pm

Re: Sinclair ZX Spectrums.
 
both boards are Rev 3 ...one was a 3B if memory serves.
I probably have enough to build up a 3rd ...but the pcb is very damaged.
traces torn off.
..and although I have an RF modulator ..I'm missing the 40 ohm speaker ..
and would also have to obtain another Keyboard membrane..
So unlikely that will ever get done.
rgds
VS

electronicskip 28th Jun 2019 4:14 pm

Re: Sinclair ZX Spectrums.
 
Trade in post used to have a supply of Sinclair spares including membranes along with tons of other retro computers and software.

Make sure you use the search box or call direct as they have 1000s of items not listed.
https://www.tradeinpost.com/

barrymagrec 28th Jun 2019 4:31 pm

Re: Sinclair ZX Spectrums.
 
I once briefly worked at the SE labs factory in Feltham where some Spectrums were built. they told me of an urgent modification to finished machines which was done by means of parking the Artic full of packaged units outside the factory and having each person doing one part of the unpacking and mod on a series of benches that snaked round the factory and back out where the re-tested and re-packed items were loaded back on to the truck.

SiriusHardware 28th Jun 2019 4:43 pm

Re: Sinclair ZX Spectrums.
 
I wonder if that was the 'dead bug' mod - early versions of the Spectrum ULA had hardware 'fixes' strapped across them. The one I personally experienced was a ZTX... style transistor sprawled over the top of the ULA, but I think there was a variant where there was a logic IC adorning the top of the ULA in similar fashion.

CHRIS_F 9th Aug 2019 2:25 am

Re: Sinclair ZX Spectrums.
 
1 Attachment(s)
Nice work, always nice to see a spectrum repaired/restored, here's one of mine, it has a new membrane/faceplate, Composite video, Muratta OKI switched mode regulator, reset switch, power L.E.D. In line power switch and a new PSU. I also have a smartcard/divMMC to load snaps instantly, I love the small size of the humble 48 but I don't like the RF or Composite picture quality, I know you can get the ZX-HD now for HDMI but I prefer the +2A models :-)

CHRIS_F 9th Aug 2019 2:35 am

Re: Sinclair ZX Spectrums.
 
3 Attachment(s)
As I said in my other reply I do love the 48K for it's size and history, but I much prefer the +2A/B +3 models, as they have the RGB port and I use an RGB to scart lead, my daily driver is this 2+A, I cut the tape deck off and put a divMMC inside, for instant loading, I first saw a cut down machine on a few years back and I just had to build my own, this one has the NMI and Reset buttons on the side with a Kempston Joystick port and a push to release SD card, the SD card extension was acrually a pain to make I had to cut open an SD to Micro-SD card adapter and solder some old floppy cable to the pins, I did try the SD card extension leads, but they were too long and the signal didn't travel, (it did on a smart card, but not with a divMMC)

Anyway, just thought you might like to see my machine as a fellow speccy enthusiast :-)

CHRIS_F 9th Aug 2019 2:43 am

Re: Sinclair ZX Spectrums.
 
Quote:

Originally Posted by ViperSan (Post 1155317)
both boards are Rev 3 ...one was a 3B if memory serves.
I probably have enough to build up a 3rd ...but the pcb is very damaged.
traces torn off.
..and although I have an RF modulator ..I'm missing the 40 ohm speaker ..
and would also have to obtain another Keyboard membrane..
So unlikely that will ever get done.
rgds
VS

Ian at Mutant Caterpillar Games had some replacement 40 ohm speakers commissioned, I couldn't find them on his site but he has them here https://www.ebay.co.uk/itm/Beeper-Re...-/192080741849

You can also get new membranes for about £8 from Phil at Retrolium https://www.retroleum.co.uk/keyboard-parts-spectrum or Sell My Retro or Dataserve Retro or ZX Renew sites :-)

Spec-chum 9th Aug 2019 6:11 pm

Re: Sinclair ZX Spectrums.
 
Obsessed, manic collector/repairer here also. These little micros were not the most advanced and high spec'd as rival machines, but they had the biggest charm, friendly and easy to learn basic which spurred on bedroom coders and got many folk into the IT industry. Sir Clive's baby was the Raspberry PI of the 1980's. :thumbsup: ViperSan on the repair.

IanBland 12th Aug 2019 5:28 am

Re: Sinclair ZX Spectrums.
 
I've got a +2 under my bed, still in the original box. I bet the cassette drive belt's gone by now :D

SiriusHardware 12th Aug 2019 5:06 pm

Re: Sinclair ZX Spectrums.
 
Assuming it is, where would one come from these days? (I ask because I also have a boxed +2 which has not been powered up for a while).

electronicskip 12th Aug 2019 6:08 pm

Re: Sinclair ZX Spectrums.
 
Quote:

Originally Posted by SiriusHardware (Post 1167726)
Assuming it is, where would one come from these days? (I ask because I also have a boxed +2 which has not been powered up for a while).

Ditto also a +3 too .

IanBland 12th Aug 2019 9:10 pm

Re: Sinclair ZX Spectrums.
 
Cassette drive belts for the +2 appear to be available on Ebay. :)

CHRIS_F 13th Aug 2019 2:01 am

Re: Sinclair ZX Spectrums.
 
Quote:

Originally Posted by electronicskip (Post 1167743)
Quote:

Originally Posted by SiriusHardware (Post 1167726)
Assuming it is, where would one come from these days? (I ask because I also have a boxed +2 which has not been powered up for a while).

Ditto also a +3 too .

Drive belts for the +3 floppy and the +2 cassette are available from Ebay or Dataserve Retro and quite a few other places, but beware the grey +2 with cassette decals on the buttons uses two belts and the Black +2A/B with the dacals above the buttons uses the one belt so make sure you order the right ones :-)

GrahamN 13th Aug 2019 8:40 am

Re: Sinclair ZX Spectrums.
 
Both the grey and black plus 2s use the same cassette main drive belt. The grey machine has a smaller belt also, but (and I'm willing to be proved wrong!), I think the cassette will work without it.

CHRIS_F 27th Sep 2019 10:39 am

Re: Sinclair ZX Spectrums.
 
Quote:

Originally Posted by GrahamN (Post 1167855)
Both the grey and black plus 2s use the same cassette main drive belt. The grey machine has a smaller belt also, but (and I'm willing to be proved wrong!), I think the cassette will work without it.

I am no expert but if it’s like some other decks I have the capstan pulley is driven by the main belt and will pull the tape through the pinch roller and probably play, but the second belt has something to do with driving the black wheels that wind the tape back into the cassette, I’m sure running it without the second belt will mangle tapes, but it may not be like my other decks and may just be to do with ff/rew auto stop.

GrahamN 27th Sep 2019 10:50 am

Re: Sinclair ZX Spectrums.
 
You're probably right. I must have changed hundreds of these belts over the years, but I can't say I've ever taken much notice. I'm probably thinking of those that use a separate belt just to drive the tape counter, and of course there isn't a counter on the Plus 2.

PsychMan 27th Sep 2019 12:10 pm

Re: Sinclair ZX Spectrums.
 
Ive just acquired a grey +2 that's In need of belts. I've ordered a kit with both of them in it.

I can take some pictures and share here if any interest


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