Fitting a PC Power Supply into a Amiga 1200 Power Supply AT or ATX? ATX This is the type of PSU found on all modern PCs and within cases. There are 2 important differences to the AT PSU. The following conditions must be met: 1) You need to have about a 1 Amp load on the 5V supply for it to work. 2) You need to connect the PS-ON line to ground for the PSU to switch on. Condition 1 is easily satisfied, an Amiga uses enough current on the 5V supply. Condition 2 gives you 2 options. 1) Connect a toggle switch or similar latching between the PS-ON wire and ground. This may not suit you if your Amiga is in a tower. 2) If you’re PSU has a mains power switch, hardwire the PS-ON and ground wires together and use the mains switch. ATX PSU wiring colour code Colour Voltage Pin(s) RED +5V 4,6,19 & 20 BLACK Ground 3,5,7,13,15,16,17 YELLOW +12V 10 BLUE -12V 12 WHITE -5V 18 GREEN PSU-ON (active low) 14 ORANGE +3.3V 1,2,11 GREY Power OK 8 PURPLE +5V standby 9 I won’t go on whit ATX as its crap to use, it can be done. But an AT is easier AT Not really used in PCs since 1998/99 due to the PC requirement that software can switch the PC off, but here the best one we can use AT PSU wiring colour code Colour Voltage RED +5V BLACK Ground YELLOW +12V BLUE -12V WHITE -5V ORANGE Power good, +5V Before you get started whit the power supply make SURE it has no more power left in it. A way to do it is to flip the switch on (WHIT OUT THE POWER CABLE IN IT), the fan will suck the power out, leave it for an hour. In the mean time prepare the cable you got from the Amiga power supply, cut the cable around 1 meter (40 inches). Strip the outside grey for around 5cm (2 inches) the blank wire is actually the yellow wire, cut it. You won’t need it. Strip the tips of the other wires so they are ready for soldering. Now open your Power supply, and heat up your solder pin. Remove the print out of its case, as you need to solder on it. You will need to remove the 2 connectors that normally go to the main board. Cut them of, leave 5cm (2inches) on the power supply. Solder the ends out of the print, but leave in it: - 1 black - 1 red - the blue one - the yellow one Next, remove the remaining wires 1 at a time and place in the cable. Make SURE you get this right or you will KILL your Amiga. Amiga Colour AT Colour Voltage RED RED +5V BLACK BLACK 0V/GND BROWN YELLOW +12V WHITE BLUE -12V YELOW NOT USED Cable side Amiga side NOTE: It appears that Commodore did not use a consistent wiring scheme for all PSU’s so please check your lead. Put the supply back together. You power supply is now ready for use Final note… THIS IS NOT THE WAY TO DO IT… this is called… A FREAKING MESS!!!!