Re: Apple IIgs motherboard pinout

[supertimer@aol.com (Supertimer)]

"Jose Ricci" <jricci@entelchile.net> wrote:

>Hi,
>
>I need to know the pinouts for the internal connectors (power supply,
>speaker, fan, etc) in the rom3 motherboard. I own one that I would like to
>put in a PC case to get a stronger power supply and cooler operation.
>Also, if someone have made this before, I would appreciate some advice.

I have done this.  First of all, before I give you the power
pinout, let me recommend that you get a multimeter from
Radio Shack or other sources too and check and
double check your wiring before connecting the PC
power supply to your IIGS motherboard after installation
in the PC case.  My first IIGS motherboard was fried
when I wired up the connector in REVERSE order.  ;-(

The power supply connector pinout is as follows:

1. ground
2. ground
3. EMPTY
4. +5 volts
5. +12 volts
6. -12 volts
7. -5 volts

Check the orientation of the connector using the empty
pin 3 on the socket.  What I recommend you do is to
use your multimeter to check everything and record
orientation and voltages down on a piece of paper.
Then use a pair of scissors and cut the connector from
the IIGS power supply with a little slack.  The PC
power supply has two motherboard connectors.  Find
and mark two ground, one +5V, one +12V, one -5V,
and one -12V wires.  Use taped labels to identify them
and double check them with the multimeter.  Then
cut these from the PC motherboard connector near
the two PC motherboard connectors.  Insert a bit of
heat shrink tubing onto each of the cut ends.  Then
splice the PC power wires to the equivalent IIGS
ones connected to the IIGS power connector.  Pull
down the heat shrink tubing over the splices and use
a lighter to heat them carefully until they shrink tight.

With the PC power supply on, use your multimeter to
check that the IIGS power connector is delivering the
right voltages from the PC power supply.  The PC
power supply has now been converted.

For the PC fan, do not use the ROM 3 motherboard
power connector.  Rather, plug the fan directly into
one of the PC power supply's connectors.  There are
usually an excess number of them.

For sound, just plug PC amplified speakers into the
stereo headphone jack at the back of the IIGS.
http://www.jdr.com/ JDR Microdevices used to sell
a set of speakers that sat in the drive bay of a PC
tower.  That would be the neatest solution.  The
speakers in that device are amplified, so they are
perfect for the IIGS.

I recommend mounting the motherboard so that the
slots are parallel to the ground.  Mounting the
motherboard with the slots perpendicular to the
ground may cause the cards to fall out.  You need
to identify the mounting holes on the IIGS mother-
board and drill holes in the PC tower case to
match.  Then use motherboard spacers to mount
the motherboard in the tower case.

You can fit your 3.5 drive into one of the drive bays
easily too.  Check out the http://www.apple2.org/
website.  Tony Diaz's article will tell you how to
do this.

Good luck!