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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: motorollin on December 04, 2005, 05:25:08 PM

Title: ATX PSU with Amiga schematic
Post by: motorollin on December 04, 2005, 05:25:08 PM
For the benefit of prismra, who asked about this, and also anyone else who is interested, here is a schematic of the cable I built to use an ATX power supply with my A1200.

(http://i298.photobucket.com/albums/mm244/motorollin/aorg/ATX-Amiga.gif)

Please check the pinout of your ATX and Amiga power supplies before connecting this. You should also check the output from the Amiga's power connector after connecting and powering on the ATX power supply, to make sure it is outputting the correct voltage for the Amiga. Pins 14 and 15 are connected to each other to make the PSU power up.

Usual disclaimer applies - this worked for me but may or may not blow your Amiga up  :roll:

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moto
Title: Re: ATX PSU with Amiga schematic
Post by: doctorq on December 04, 2005, 05:40:48 PM
Ehh, shouldn't the red and the yellow wire go to two different pins on the A1200 connector?
Title: Re: ATX PSU with Amiga schematic
Post by: Framiga on December 04, 2005, 05:46:49 PM
pins 19 and 20 are both +5v (its ok due the thin ATX wires)

http://pinouts.ru/data/atxpower_pinout.shtml

Title: Re: ATX PSU with Amiga schematic
Post by: Piru on December 04, 2005, 05:54:03 PM
@motorollin

You should perhaps mark from which side the connectors are seen (or else someone might mirror the connections, though that should be caught when testing the voltages).

Also, this configuration doesn't work (or rather always works;) for PSUs that don't have the power switch on the back, this config is always powered. I'd suggest attaching the powerswitch between pins 14 and 15 instead of just short circuiting the pins.
Title: Re: ATX PSU with Amiga schematic
Post by: tonyvdb on December 04, 2005, 05:54:21 PM
Will this work on an Amiga 4000?
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 04, 2005, 06:31:44 PM
Quote

doctorq wrote:
Ehh, shouldn't the red and the yellow wire go to two different pins on the A1200 connector?

No they're connected to the same pin on mine.

--
moto
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 04, 2005, 06:34:52 PM
Quote

Piru wrote:
@motorollin

You should perhaps mark from which side the connectors are seen (or else someone might mirror the connections, though that should be caught when testing the voltages).

You can tell by the location of the square holes.

Quote

Piru wrote:
Also, this configuration doesn't work (or rather always works;) for PSUs that don't have the power switch on the back, this config is always powered. I'd suggest attaching the powerswitch between pins 14 and 15 instead of just short circuiting the pins.

Quite correct. My ATX PSU had a power switch on the back so I didn't need to do this. But as you say a switch between the two pins would add a power switch to the configuration.

--
moto
Title: Re: ATX PSU with Amiga schematic
Post by: Piru on December 04, 2005, 06:40:01 PM
@motorollin
Quote
You can tell by the location of the square holes.

I don't see any square hole on the amiga side connector.

It might be obvious to you (you did draw it after all), but it might not be to everyone else.
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 04, 2005, 06:43:33 PM
Quote

Piru wrote:
@motorollin
Quote
You can tell by the location of the square holes.

I don't see any square hole on the amiga side connector.

It might be obvious to you (you did draw it after all), but it might not be to everyone else.

Ahhhh yes of course. You can tell by the colours of the wires. When I drew the schematic, I did it as if you were looking at the connector.

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moto
Title: Re: ATX PSU with Amiga schematic
Post by: lurkist on December 04, 2005, 08:30:06 PM
Soo... has the picture at the top been corrected / confirmed?
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 04, 2005, 08:46:42 PM
The picture is correct. I have the cable sitting next to me  :-)

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moto
Title: Re: ATX PSU with Amiga schematic
Post by: prismra on December 05, 2005, 06:23:04 PM
Where do I get a connector that fits the A1200 power plug?
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 05, 2005, 06:24:20 PM
From an A1200 PSU?  :-)  I just cut mine off.

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moto
Title: Re: ATX PSU with Amiga schematic
Post by: prismra on December 05, 2005, 06:37:36 PM
What's to stop me from just buying a UK 220v PSU for it and using a step-down (?) converter from Radio Shack or something?
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 05, 2005, 07:08:56 PM
Can you elaborate, I'm not sure I understand what you mean  :-)

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moto
Title: Re: ATX PSU with Amiga schematic
Post by: prismra on December 05, 2005, 07:12:29 PM
Well aren't there converter that allow you to use UK powered devices on a US wall plug?
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 05, 2005, 07:21:18 PM
Yes you could use an inverter which would take a 110v suppply from a US outlet and supply 220v. Then you could connect a UK Amiga PSU to the 220v supply.

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moto
Title: Re: ATX PSU with Amiga schematic
Post by: prismra on December 05, 2005, 08:47:40 PM
Will I have any issues with a PAL motherboard.  I'm never going to connect it to a TV (I don't think).  Probably going to track down a 1084 Commodore monitor so...
Title: Re: ATX PSU with Amiga schematic
Post by: delshay on December 05, 2005, 08:58:16 PM
iv added a rocker switch to my a1200 desktop.

one wire goes to earth ( inside the a1200 ) & a single wire comes out & goes to the power on ( green wire )..

this is great as i can reset/turn on my a1200 without breaking my back..
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 05, 2005, 09:06:13 PM
Quote

prismra wrote:
Will I have any issues with a PAL motherboard.  I'm never going to connect it to a TV (I don't think).  Probably going to track down a 1084 Commodore monitor so...

Hmmm I'm not sure to be honest. I don't know anything about the 1084. A google search may reveal whether it can display pal screenmodes. Is there a reason you're using a PAL Amiga? Why not NTSC?

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moto
Title: Re: ATX PSU with Amiga schematic
Post by: prismra on December 05, 2005, 09:23:47 PM
I may be able to get one on the cheap.  So that may be how I'm going to do it.

The two problems I have are:

What monitor to get (no 'new' VGA monitor supports 15khz.)

Where to get a god damn 110v power supply.

Grrrr.
Title: Re: ATX PSU with Amiga schematic
Post by: motorollin on December 05, 2005, 09:48:23 PM
I've had a look on eBay and can't find any 110v PSUs. Your best bet would probably be to get an inverter from RS or a local hardware store, and then you can use any 220v PSU.

Also, I've discovered that 1084s come in PAL and NTSC flavours, so you would need to get the correct one for your Amiga. The cheaper alternative would be to use a TV. The best, but probably most expensive option is to get a scandoubler and use a VGA monitor.

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moto