User`s guide

Fatter +5, +12, and Ground leads should protect you power supply and reduce
circuit noise.
If audio noise in your stereo card output and/or system bombing due to
noise glitches were problems, they may be eliminated. A lot depends upon which
cards you've installed, which slots they are in, and whether your IIgs is a ROM-
01 or ROM-03.
The motherboard circuit traces supplying power to each Slot are fairly
skimpy, especially on ROM-01 boards. A heavy power user in Slot 7 can produce
significant noise up and down the entire Slot 'backplane'.
The cure is to remove the motherboard and run leads to a couple Slots ...
First, flip over the motherboard and get oriented. Below is a quickie
sketch showing the Power Connector points as well as key power pins for a Slot.
The view is from the _Bottom_ with the _Back_ of the motherboard facing you:
Bottom of Motherboard
Power Connector Socket Slot
X GND +12V (pin 50) X X (pin 1)
X GND X X
.
X +5V .
X +12V .
X -12V
X -5V X X
GND (pin 26) X X (pin 25) +5V
.... Ground Plane Area (plug shields, etc. connected here) ....
|
|______________ Back Edge of Motherboard _________________________
A good way to make sure you know what's where is to use an Ohm meter to
check Resistance from pin 26 (GND) to a metal plug shield near the back of the
motherboard. (Set your meter to Ohms X1. Touch one meter lead to pin 26 and the
other to a metal plug shield. Resistance should read nearly zero. Reverse the
leads and repeat the check. Again, Resistance should read nearly zero.)
Repeat the check for R between pin 26 and the GND points on the Power
Connector socket. R should be nearly zero. Using a marker pen or white-out, mark
pin 26 (GND) on Slots 3 and 7. Also mark the GND points of the Power Connector
socket.
GND: On the bottom side of the motherboard, connect a Black #16 gauge wire from
one of the Ground points of the Power Connector socket to the Ground plane area
near the back of the motherboard. Run a short Black #16 gauge wire from pin 26
of Slot 3 to the Ground plane; run a short Black #16 gauge wire from pin 26 of