Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: RetroNinja on September 19, 2023, 11:32:22 PM
-
For AmigaKit's power supply cable:
A2000 ATX PSU Power Adapter Cable for Amiga 2000
[ADAPSU010]
Does anyone know if the ATX power supply has to have a -5V line? Or, does this cable convert a spare +5V to -5V? Another way to say the same thing, is there any intelligence in this adapter or is it just a straight through cable converter?
-
From the photos online it's a passive cable that appears to connect -5V from the ATX supply to -5V on the A2000 connector (white wire).
https://www.amigastore.com/a2000-power-adapter-cable-amiga-2000-p-998.html
It's fairly rare to see much that uses -5V. All I can think of is a few older Zorro 2 expansion cards and video processing expansions. The A2000 itself will operate fine without the -5V supply.
-
Huh, I was under the impression the A2000 needed for the -5V for the boot process. Thanks for the info.
-
I was under the impression the A2000 needed for the -5V for the boot process.
The A2000, as with other Amigas, only needs +5V to boot normally. If you want audio output and RS232 serial, then you need both +12V and -12V as well. Most floppy drives and mechanical hard drives need both +5V and +12V.
The A2000 also needs the 50Hz/60Hz tick signal that normally comes from the power supply. It won't boot without it as this timing reference increments some of the hardware timers. For non-original power supplies that don't provide the 'tick' signal, you can change main board jumper J300 from external to internal which drives the timer from an internally derived signal instead.