Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: TheGoose on March 14, 2009, 09:17:55 PM

Title: A1200 power through the floppy molex connector?
Post by: TheGoose on March 14, 2009, 09:17:55 PM
Um, this works fine it seems. Are there some caveats to rigging your A1200 this way?

Thanks for info...

Title: Re: A1200 power through the floppy molex connector?
Post by: save2600 on March 14, 2009, 09:30:45 PM
Sounds like you're going 'in' through the 'out' door so to speak.  LOL!

Does the audio work on your setup? Is there a -5v present?

What did you do... jury rig a PC power supply to it?


Title: Re: A1200 power through the floppy molex connector?
Post by: AmigaMance on March 14, 2009, 09:44:51 PM
 You mean powering your Amiga *only* through the floppy connector? I tried it once and my Amiga didn't even boot. My configuration is similar to yours.
 
Title: Re: A1200 power through the floppy molex connector?
Post by: TheGoose on March 14, 2009, 09:47:50 PM
Well, I did. Jumped an ATX PSU and hooked it up to see if this old MB worked. It came up just fine to the ROM screen.

I knew about this from my main PPC machine. Phase 5 would recommend you do this with the Blizzard PPC. So, if that couldn't hurt, why would it here I reckoned; famous last words...

 :lol:
Title: Re: A1200 power through the floppy molex connector?
Post by: doctorq on March 14, 2009, 10:25:38 PM
Quote

Well, I did. Jumped an ATX PSU and hooked it up to see if this old MB worked. It came up just fine to the ROM screen.


There is no problem in doing this, but you will have sound issues unless you hook a -5V supply to the machine.

Running the machine with only this power source with a variety of expansion might not be a clever idea.
Title: Re: A1200 power through the floppy molex connector?
Post by: TheGoose on March 14, 2009, 10:52:23 PM
Ah, that's the advice I was looking for, thanks.

Off to amigakit again...
Title: Re: A1200 power through the floppy molex connector?
Post by: AmigaSoft on March 15, 2009, 11:00:24 AM
I did this last week, Had to use an A500 power suply though to get the A1200 to boot.
Title: Re: A1200 power through the floppy molex connector?
Post by: delshay on March 15, 2009, 01:05:16 PM
-12v is missing in this thread,not unless someone is doing something special to use -5v.
Title: Re: A1200 power through the floppy molex connector?
Post by: brianb on March 15, 2009, 04:12:07 PM

I personally wouldn't bring in power through the floppy connector...

My $0.02...

- You may be bypassing some important power conditioning circuits.

- You won't bring in the -12v line, which is probably necessary for the audio and serial circuits.

- You won't have the earth ground line.  Maybe not a big deal, but could possibly cause some audio noise.

The standard power supply on the 500/600/1200 has the following lines...

+12V
-12V
+5V
Ground
Earth Ground

I learned a lot about the PS building my "mega" power supply  for my 1200...

http://www.amiga.org/gallery/index.php?n=2905=10



Title: Re: A1200 power through the floppy molex connector?
Post by: brianb on March 15, 2009, 04:13:34 PM

I personally wouldn't bring in power through the floppy connector...

My $0.02...

- You may be bypassing some important power conditioning circuits.

- You won't bring in the -12v line, which is probably necessary for the audio and serial circuits.

- You won't have the earth ground line.  Maybe not a big deal, but could possibly cause some audio noise.

The standard power supply on the 500/600/1200 has the following lines...

+12V
-12V
+5V
Ground
Earth Ground

I learned a lot about the PS building my "mega" power supply  for my 1200...

http://www.amiga.org/gallery/index.php?n=2905=10



Title: Re: A1200 power through the floppy molex connector?
Post by: delshay on March 15, 2009, 04:54:20 PM
*correct* i have no idea where -5v was used on the amiga unless it was added in for something special.
Title: Re: A1200 power through the floppy molex connector?
Post by: orange on March 15, 2009, 05:26:09 PM
just don't ever use two PSUs, it will fry your Amiga.

Also, the PCB 'traces' for floppy power are probably not designed for so much current, so it would be better to connect both 'points' (with same PSU).

I did it once for testing and A1200 did boot.
Title: Re: A1200 power through the floppy molex connector?
Post by: doctorq on March 15, 2009, 05:33:31 PM
Quote

-12v is missing in this thread,not unless someone is doing something special to use -5v.


A slight misprint from my side; it's -12V, not -5V. The other post got me confused there for a second.