New (to me Speccy)

A place to discuss the ZX80's and ZX81's younger brother - the Sinclair ZX Spectrum
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Spinnetti
Posts: 253
Joined: Sat Sep 12, 2020 11:29 pm

New (to me Speccy)

Post by Spinnetti »

Been wanting one since the day they were introduced. I could only afford a TS1000, and later got the TS2068 (new).. Time passed, life moved on, and I'm on the nostalgia kick and got one off ebay UK. What do I need to do to run this thing in he USA? I get I'll need a power adapter (Can I use the one from my TS2068?), and I plan a composite mod, but what else do I need to do to output for NTSC? If I got an HDMI card, does it still require mods, or will that handle the difference? I'm on the Speccy Next kickstarter, so I don't necessarily need too many mods, but would like to see it power up.

Thanks!
Zeddy: ZX80, ZX81/ZXpand, TS1000/ZXpand, TS1500/Zxpand+
Speccy: 48k, +, +2, +3, TS2068, "Bare Metal" Pi, Next KS2, IF1/Microdrives/Vdrive/Light Gun/VGA-Joy
QL: Minerva/QL-VGA/Custom PSU
C5: 24v, LiFE battery, Disc brakes
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1024MAK
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Location: Looking forward to summer in Somerset, UK...

Re: New (to me Speccy)

Post by 1024MAK »

In my reply, I’m assuming you are getting a rubber key 16k or 48k ZX Spectrum, or a ZX Spectrum plus.

Any 9V DC PSU that has a smooth or regulated output rated at 1.4A or more will do. The really important point though is that you double check the the output polarity is correct. The ZX Spectrum requires positive on the outside and negative on the inner contact.

A U.K. ZX Spectrum will work quite happily, but then the question is how do you see it’s video picture. If the keyboard membrane is okay, then if you press and hold a key (except any of the shift keys) you should hear a faint clicking noise from the internal loud speaker.

Yes, the first step to get a video picture is to do the composite modification. That then gets round the modulator problem (U.K. models output on/around UHF channel 36).

If you have a TV / monitor or video capture device that can accept a PAL 625 line 50Hz video input, then you’re good to go.
Converting the ZX Spectrum to 60Hz NTSC is possible, but you need to change both the colour crystal and the ULA. NTSC ULA chips are not cheap. And as the vast majority of games were written with the timing of the PAL 625 line 50Hz video system, some will not work properly with the different timings of the 60Hz NTSC system.

In Europe, a lot of modern TVs will correctly display a 60Hz NTSC video signal (even if the specifications/instructions don’t mention it), but alas it appears that most of the TVs that are/were sold in America can’t correctly display a PAL 625 line 50Hz video signal. It is still worth trying though.

I don’t have a HDMI Interface for my ZX Spectrums. But keep in mind that the timing of HDMI video signals for standard definition are based on the timing of the older analogue 60Hz NTSC video and PAL 625 line 50Hz signals. And not all HDMI TVs will work correctly with a HDMI signal based on a PAL 625 line 50Hz signal :(

Other users of U.K. 8 bit computers in 60Hz NTSC land mostly appear to use a video capture device.

Mark
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Spinnetti
Posts: 253
Joined: Sat Sep 12, 2020 11:29 pm

Re: New (to me Speccy)

Post by Spinnetti »

Thanks Mark. It is a 48k rubber key model. I got a spare keyboard membrane also. So sounds like best bet is to hook up to various displays and see if something works - I imagine something will sync :) If not, I guess its ok. I have the TS1500, TS2068, and the Next on they way so it can pretty up my desktop.
Zeddy: ZX80, ZX81/ZXpand, TS1000/ZXpand, TS1500/Zxpand+
Speccy: 48k, +, +2, +3, TS2068, "Bare Metal" Pi, Next KS2, IF1/Microdrives/Vdrive/Light Gun/VGA-Joy
QL: Minerva/QL-VGA/Custom PSU
C5: 24v, LiFE battery, Disc brakes
superfo
Posts: 74
Joined: Wed Jul 08, 2009 9:12 am

Re: New (to me Speccy)

Post by superfo »

Buy small monitor like this one, it support both PAL and NTSC

https://www.amazon.com/Hikity-1024X600- ... 720&sr=8-3
Spinnetti
Posts: 253
Joined: Sat Sep 12, 2020 11:29 pm

Re: New (to me Speccy)

Post by Spinnetti »

Funny, I was looking at just those things on amazon and will no doubt pick one up. I just got my Composite mod board from the UK, time to put it in the 1500 along with a DC/DC power to replace the 7805 and give it a go, and then do the speccy (not arrived yet, along with a QL lol)
Zeddy: ZX80, ZX81/ZXpand, TS1000/ZXpand, TS1500/Zxpand+
Speccy: 48k, +, +2, +3, TS2068, "Bare Metal" Pi, Next KS2, IF1/Microdrives/Vdrive/Light Gun/VGA-Joy
QL: Minerva/QL-VGA/Custom PSU
C5: 24v, LiFE battery, Disc brakes
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