AT Tower Case Fitting
by Mark Bedingfield
Using an AT style
power supply is not all too difficult. Do remember
you cannot use it with a CT60. Only ATX supplies
are suitable in that case. Although, it is possible
to use an ATX supply with any Atari, given the
right adapters. I will first look at the different
types of PSU (Power Supply Unit), avaliable
to the PC market.
Firstly the classic
AT style PSU. This is used
for the 286/386/486, Pentium and Pentium MMX
ATX style PSU. This is used
for the Pentium 2/3/4 and Athlon type mainboards.
you need to do with an AT supply is build an
extension lead that switches one pin configuration
to another. The layout is thus, for AT:
And thus for
Now, the way
I did it, and it ain't pretty, is to desolder
a male AT PSU plug from a 486 mainboard and
then rewire it to suit on a new female socket
that can be bought from any electronics
shop. Jaycar or Radio Parts here in Australia.
A quick surf over to Maplin shows it in their
catalogue, too. It is also possible for the AT
socket to be purchased, rather than destroy
a perfectly useless 486 board.
Pay very close
attention to the orientation of the ends of
the power connector, reversing it may kill your
Falcon. The orientation is obviously not critical
at the PSU end, as long as you pay attention
to the colour coding of the wire. Convention
in the PC world, dictates that the four ground
pins be placed side by side, as above. Note, the
12 V line on the Falcon power supply is blue,
not yellow, don't be tempted to wire the blue
wire from the AT PSU to the Falcon. Basically,
wire all 5 V (red) connectors from the AT
PSU to the 5 V connectors on the Falcon end,
repeat this for the 12 V (yellow) and GND (black)
pins. It is also a good idea to insulate the
back of the male socket, using heat shrink.
The actual schematic appears below. From what
I understand, there are some AT PSUs that require
a live active good signal in order to switch
on, I have yet to see one that does, but that
may be just luck.
In my case, I
used red, black and blue wire, so that it would
look more like an Atari and less like a PC.
Now all that remains is to put your Falcon mainboard
in the tower case.