Zx Spectrum 128k +2 (SCART to VGA or HDMi)

elmanoduarte
Posts: 27
Joined: Thu May 11, 2023 12:58 pm

Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by elmanoduarte »

Hi ..greatings for all here i m ..again.

Now... best way to make conversion from the RGB -SCART to VGA monitor or HDMi ?

Is in fact that possible?

Regards
Duarte
User avatar
1024MAK
Posts: 5103
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by 1024MAK »

For HDMI the best method is by using an interface that plugs into the expansion port/edge connector. For example the ZX-HD HDMI INTERFACE.

There is also the RGB to HDMI using a Pi Zero and a small CPLD project, but I don’t know if or who is making these at the moment.

For VGA, have a look at the ZX-VGA-JOY.

I don’t use any of these with a ZX Spectrum, so am unable to help further.

There may well be other devices that I don’t know about.

There are SCART to HDMI converters on trading sites. But it’s a minefield buying one. You need one that does SCART RGB. All the very inexpensive units don’t work with SCART RGB. Some of the units in metal cases may work.

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.
elmanoduarte
Posts: 27
Joined: Thu May 11, 2023 12:58 pm

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by elmanoduarte »

Ok, many thanks for your help.
O will see ot, and mabe i ll test some converter s.
An ebay seller said it has a small box feeded by a small power supply, he say ot could work.
Its not much, o will test.
For much money, its better nuy a 24" TV with scart. :)

Thanks,
Best regards
elmanoduarte
Posts: 27
Joined: Thu May 11, 2023 12:58 pm

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by elmanoduarte »

Soon i will have it.
I will let the result here.
Let see what happen! :roll:
elmanoduarte
Posts: 27
Joined: Thu May 11, 2023 12:58 pm

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by elmanoduarte »

Hi,,,
Just to post..

After make a working Scart cable to RGB output from spectrum to Tv, then tried a converter from aliexpress where says it will convert Scart to HDMi, i have small power suply to. But it does not converter good... the monitor HDmi it makes a blue screen, it shoes the sound... but just that.
Does not make a rite working convertion.
Any idea????
User avatar
Flatulentia
Posts: 93
Joined: Sun May 14, 2023 3:58 pm
Location: Cambridgeshire, UK

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by Flatulentia »

What do the instructions with the converter say about how it converts SCART to HDMI?

If it's just taking the composite video signal and converting that, one of the MINI AV2HDMI branded converters you can buy very cheaply on eBay may be able to do the same thing if you can provide composite video via an RCA plug.

The only drawback is that they expect an interlaced input which the ZX Spectrum composite video signal isn't, so you may experience some vertical jitter when using one.

I took one apart and mounted the PCB inside a ZX81 and it works very well.
ZX81 with ZiLOG Z84 CMOS Z80, 32KB battery-backed Toshiba 55257 SRAM with charge status LED, Wilf's "Why Wait?" mod and switch-mode 5V regulator. 50/60Hz mode switch, composite video output with Zigg's back porch mod and 1080p60 HDMI output.
Lardo Boffin
Posts: 2160
Joined: Sat Nov 26, 2016 2:42 am

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by Lardo Boffin »

I have one of these for a BBC Micro and also used one with a Toastrack 128:

https://www.ebay.co.uk/itm/234217687770 ... media=COPY

It gave superb results.

Some photos:

https://www.sinclairzxworld.com/viewtop ... 614#p44614
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
User avatar
1024MAK
Posts: 5103
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by 1024MAK »

Lardo Boffin wrote: Fri Jun 09, 2023 12:14 pm I have one of these for a BBC Micro and also used one with a Toastrack 128:

https://www.ebay.co.uk/itm/234217687770 ... media=COPY

It gave superb results.

Some photos:

https://www.sinclairzxworld.com/viewtop ... 614#p44614
These are made using this “RGB to HDMI using a Pi Zero and a small CPLD project” (link in my earlier post).

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.
User avatar
1024MAK
Posts: 5103
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by 1024MAK »

elmanoduarte wrote: Fri Jun 09, 2023 2:12 am Hi,,,
Just to post..

After make a working Scart cable to RGB output from spectrum to Tv, then tried a converter from aliexpress where says it will convert Scart to HDMi, i have small power suply to. But it does not converter good... the monitor HDmi it makes a blue screen, it shoes the sound... but just that.
Does not make a rite working convertion.
Any idea????
So, just to be clear, SCART is the name for the connector and what video, audio and control signals it may carry, not a definition of what actual video signal is carried or used by particular equipment.
SCART can carry one of a number of different video signals. The two most common are:
  • Composite video
  • Analogue RGB video
If you have a RGB SCART lead, this is wired for Analogue RGB video, hence will not work if it’s connected to a converter that only accepts a Composite video input.
Some converters just don’t like the non-standard video signals from the ZX Spectrum.

Can you link to the item you purchased?

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.
mikeh_nz
Posts: 67
Joined: Sat Feb 04, 2023 8:03 am
Location: Seattle

Re: Zx Spectrum 128k +2 (SCART to VGA or HDMi)

Post by mikeh_nz »

Ok - Too Much Information (TMI), but here’s my experiences with these things

ZX-HD works very well and works better than rgbToHdmi on the standard spectrum 16k/48k (it can show bright colours). It auto detects and works with almost all spectrums. It has slightly more of a finished product feel - as it auto detects the different sorts. It connects to the edge connector and I believe eavesdrops on writes to screen memory. It keeps its own internal screen buffer and then just renders it to the screen.

The rgbToHdmi with a spectrum 16k/48k with a vla82s ula, Harlequin 48K, spectrum +2, or later works just as well. It can work on a zx81 and other computers too. (screenshots) So more versatile. Once you’re set up on a computer it’s no hassle, but there’s a bit of clunkiness swapping between different machine types. I keep finding myself saying “oh - I can use it with {new retroComputer I’m playing with}, I just need to wire up a cable”. It works by basically measuring the colour/brightness at the center of a pixel (at least where it thinks the center is). It’s configured with knowledge of the size and shape of the pixels and can render the whole pixel crisply.

I think both are awesome and produce pictures that look like an emulator is running it. Some people might dislike this sharpness of the image.

This is compared to the cheap generic convertors that have to detect the changing colours at the edges of the pixels. They also have higher latency than the above two so in fast playing games you might notice some “ever so slight” lag between your input and the response on the screen. Reasonably blurry output.

For generic convertors, the retrotink is really good and much better than the cheap convertors. Sharp image too.

I’ve personally tried / have:
  • Rgb to hdmi x2 (one with the analog board, one without)
  • Zx-HD
  • Mini AV2hdmi
  • Retrotink Rgb scart to hdmi
  • …it seems a shop-aholic problem with these things!
I use the
  • Rgb to hdmi for the zx81 and bbc b.
  • Zx-hd for the spectrums.
  • RetroTink for the Atari 2600 (modded for Rgb output).
  • Mini av2hdmi for when I have a computer in pieces (Eg recapping, memory upgrade, fixing something..) and just want to check that it’s still working


Hope this of some use…
Post Reply