ZX81 monitor

Discussions about Sinclair ZX80 and ZX81 Hardware
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PokeMon
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Re: ZX81 monitor

Post by PokeMon » Thu Sep 15, 2016 11:32 pm

You may try this - just to solder 5 wires (3 to the main board and 2 for a RCA plug or similar. ;)
http://www.sellmyretro.com/offer/details/3712

bru65pag
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Re: ZX81 monitor

Post by bru65pag » Thu Nov 17, 2016 11:03 pm

Hello PokeMon.
The ZX8-CCB seems like what I need to connect a recently acquired ZX-81 to a recent computer monitor with VGA and HDMI interfaces.
Reading your explanation on sellmyretro.com: "Video output could be provided outside the case by implementing a 3.5mm jack or similar". So, assuming I implement the suggested 3.5mm jack: Could I then simply buy any cable with a 3.5mm male jack on one hand, and a VGA connector on the other hand to make my ZX81 picture appear on my monitor?
Sorry if it seems like a basic question, but I have ZERO clue on how all these video signals work...

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1024MAK
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Re: ZX81 monitor

Post by 1024MAK » Fri Nov 18, 2016 2:05 am

With the ZX8-CCB fitted, a ZX81 can output a monochrome (black and white) composite video signal. Most TVs will accept this signal, either via the (normally) yellow coloured phono / RCA / Cinch connector, or via a SCART connector if you either make up your own cable, or use a suitable connector adaptor that has a phono / RCA / Cinch connector.

Composite video signals are 625 line, 50Hz field freq, 15625Hz line freq (in the UK) signals. The same as the old analogue VCRs used.

VGA is a multicolour analogue system, but most VGA monitors and TVs with VGA inputs are not capable of working with 15625Hz line freq signals.

HDMI is a very modern digital standard that was not even dreamed about at the time of the ZX81, let alone invented.... So surprise, surprise, the ZX81 is not compatible.

Most people reuse the phono / RCA / Cinch connector on the modulator, then use a phono to phono cable ;)

Mark

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mrtinb
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Re: ZX81 monitor

Post by mrtinb » Fri Nov 18, 2016 7:29 am

You need a monitor that has the "round yellow" connector (in picture: VIDEO). The "blue" connector is not sufficient (in picture: PC IN).

Image
Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube

bru65pag
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Re: ZX81 monitor

Post by bru65pag » Fri Nov 18, 2016 7:13 pm

Good evening everybody,

Thanks for your answers. I'm not done yet ;-) My computer monitor has the following connectors:
monitorConnections.jpg
monitorConnections.jpg (11.14 KiB) Viewed 906 times
Nothing that you guys have mentioned (Beware, the yellow connection you see on the left is for audio). I'm not talking about a TV here, but a monitor. Is there anything I can do, with or without the ZX8-CCB, to have the ZX81 displayed on it?

Thanks again for your support. Bruno.

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mrtinb
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Re: ZX81 monitor

Post by mrtinb » Fri Nov 18, 2016 7:56 pm

Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube

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1024MAK
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Location: Looking forward to summer in Somerset, UK...

Re: ZX81 monitor

Post by 1024MAK » Sat Nov 19, 2016 12:54 am

To use that monitor, you need a box of electronics that takes in a composite video signal and which converts it, and outputs a VGA signal (which then goes to your monitor).

This is one I found on eBay http://pages.ebay.com/link/?nav=item.vi ... ID=EBAY-GB

Note that I have not tried one of these with a ZX81 (yet). It's on my list of things to do when I have lots of free time (which I'm not getting very far with this year so far :( ).

Be careful when searching, as there also exists cheaper versions that take in a VGA signal and output a composite video signal. And some of the sellers descriptions are not very clear on which type they are selling.

Mark

ZX79
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Re: ZX81 monitor

Post by ZX79 » Thu Jan 04, 2018 3:57 pm

Hello,

Although not a very practical solution to analogue display, there is an all Sinclair solution with a Sinclair Microvision TV.

Huw
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PokeMon
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Re: ZX81 monitor

Post by PokeMon » Thu Jan 04, 2018 7:34 pm

That's pretty cool. :lol:

axtelle
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Re: ZX81 monitor

Post by axtelle » Fri Jan 05, 2018 6:37 pm

Here you go this may do the trick - take the CV from the ZX81 and connect via Scart to this:

https://www.ebay.co.uk/itm/382032513687 ... 1436.l2649

then a HDMI to DVI lead to your monitor.
Last edited by axtelle on Fri Jan 05, 2018 6:51 pm, edited 1 time in total.

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