Author Topic: Use MP1just as SCART cable, not power supply ?  (Read 3281 times)

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Offline cpcitor

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Use MP1just as SCART cable, not power supply ?
« on: 22:53, 22 October 13 »
Hello,

On my vacation location I have a french MP-1 power adapter for CPC 464. It outputs RGB signal through a SCART connector (no RF modulation or whatever). It works but there's no 12V only 5V so it can't power a CPC6128 disk drive.

I'm considering:
I can't test that now (no power supply, no cable, no tools).

Does anyone know if an unpowered MP1 can function as a cable ?

If not, I guess it should work when the MP-1 is powered, too. It just looks silly to have a device that produces unused +5V while the CPC is powered by the PC power supply.

When it's known (either someone answers or I try), I will update the wiki page Amstrad MP1/MP2 modulator - CPCWiki.
Had a CPC since 1985, currently software dev professional, including embedded systems.

I made the first CPC cross-dev environment that auto-installs C compiler and tools: cpc-dev-tool-chain: a portable toolchain for C/ASM development targetting CPC.

Offline redbox

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #1 on: 22:56, 22 October 13 »
It works but there's no 12V only 5V so it can't power a CPC6128 disk drive.

You could get rid of the internal 3" drive and replace it with a HxC as they only require 5v.

Then you won't need the 12v at all.

Offline Bryce

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #2 on: 22:57, 22 October 13 »
I'm not sure what you mean with the MP-1. The CPC already outputs RGB, you don't need an MP-1 to do that. The MP-1 takes the RGB and converts it to UHF. Or is this some weird modded version?

If the missing 12V is the problem, here's a guide on how to convert an MP-1 to an MP-2: Convert an MP1 into an MP2 - CPCWiki

Bryce.
« Last Edit: 23:01, 22 October 13 by Bryce »

Offline redbox

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #3 on: 23:20, 22 October 13 »
I'm not sure what you mean with the MP-1. The CPC already outputs RGB, you don't need an MP-1 to do that. The MP-1 takes the RGB and converts it to UHF. Or is this some weird modded version?

There are French versions that output SCART.

Offline cpcitor

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #4 on: 23:22, 22 October 13 »
I'm not sure what you mean with the MP-1. The CPC already outputs RGB, you don't need an MP-1 to do that. The MP-1 takes the RGB and converts it to UHF. Or is this some weird modded version?

As written, the french MP-1 doesn't do RF modulation: at the time SCART was already mandatory on french TVs and its superior quality made RF modulation obsolete.

The french MP-1 boils down to power supply plus SCART connector outputting voltage-compliant RGB signal (see TV SCART cable - CPCWiki about voltage compliance).

In other words, no need to make a cable when I already have one even if it's big and heavy a has a "Amstrad MP-1" label on it.  ;)

If the missing 12V is the problem, here's a guide on how to convert an MP-1 to an MP-2: Convert an MP1 into an MP2 - CPCWiki

Bryce.

Thanks for the link. That's interesting although it's more work.
Had a CPC since 1985, currently software dev professional, including embedded systems.

I made the first CPC cross-dev environment that auto-installs C compiler and tools: cpc-dev-tool-chain: a portable toolchain for C/ASM development targetting CPC.

Offline Bryce

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #5 on: 23:44, 22 October 13 »
Wow I didn't know these Péritel versions existed, do you have pictures?

Bryce.

Offline Gryzor

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #6 on: 20:51, 23 October 13 »
I saw this on the wiki earlier today. Damn, another thing to track down?

Offline cpcitor

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #7 on: 23:12, 23 October 13 »
Wow I didn't know these Péritel versions existed, do you have pictures?

Bryce.

I've uploaded two pictures: overview and connector details.
Amstrad MP1/MP2 modulator - CPCWiki

Regards,
Had a CPC since 1985, currently software dev professional, including embedded systems.

I made the first CPC cross-dev environment that auto-installs C compiler and tools: cpc-dev-tool-chain: a portable toolchain for C/ASM development targetting CPC.

Offline Bryce

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #8 on: 10:52, 24 October 13 »
Cool. And even photographed on a tradition French table cloth to add credibility :)

Bryce.

Offline cpcitor

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #9 on: 11:56, 24 October 13 »
Cool. And even photographed on a tradition French table cloth to add credibility :)

Bryce.

Glad you like the raster effects on the table cloth. Both horizontal and vertical, wow ! You can't imagine how hard it is to finetune the cloth's CPU cycles.  ;)
Had a CPC since 1985, currently software dev professional, including embedded systems.

I made the first CPC cross-dev environment that auto-installs C compiler and tools: cpc-dev-tool-chain: a portable toolchain for C/ASM development targetting CPC.

Offline Gryzor

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #10 on: 12:36, 24 October 13 »
Should have framed it with some wine and bagels.


...next time I shoot something I'm putting a souvlaki next to it (hope the tzatziki is not to runny though)

Offline Bryce

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #11 on: 12:47, 24 October 13 »
Don't forget the Ouzo!!

Bryce.
« Last Edit: 14:04, 24 October 13 by Bryce »

Offline Gryzor

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #12 on: 12:52, 24 October 13 »
Then I should also include some fine cheese. Or an octopus. This would get out of hand soon.

Offline redbox

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #13 on: 13:46, 24 October 13 »
Don't forget the Oozo!!

"One bottle of Ouzo-destructo and ooh the regret" - Marsha Klein, Spaced.

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #14 on: 20:26, 26 October 13 »
lol.

Offline cpcitor

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Re: Use MP1just as SCART cable, not power supply ?
« Reply #15 on: 16:15, 05 November 13 »
Does anyone know if an unpowered MP1 can function as a cable ?

Hello all,

I have not yet actually tried, but I opened my MP1 and posted photos on Amstrad MP1/MP2 modulator - CPCWiki .

In the MP1, RGB sync and ground from the CPC are wired straight to the SCART connector. Not even a resistor. So, powering a CPC by other means and plugging to an unpowered MP1 will send the signals to the TV.

Still, there is a difference between powering the MP1 and leaving it off:
  • (not sure, from memory) a signal named blank, that says input is RGB not composite
  • Slow switch: RGB signal is active and has priority
  • Fast switch: a signal that deals with overlaying the RGB signal from SCART onto another video source.

The MP1 send 12V to both slow switch and fastswitch (although the standard says 12V for slow switch and 1V-3V, 1V nominal for fast switch).

So, an unpowered MP1 is like the SCART cable described on TV SCART cable - CPCWiki without the battery. See there the consequence.

I may test that or not depending on whether I power my CPC with a PC power supply (easier but noisy) or transform my MP1 into an MP2 as @Bryce suggested.

Cheers,
Had a CPC since 1985, currently software dev professional, including embedded systems.

I made the first CPC cross-dev environment that auto-installs C compiler and tools: cpc-dev-tool-chain: a portable toolchain for C/ASM development targetting CPC.