APPLIED ENGINEERING GS POWER
By Cameron Brawn
Copyright (c) 1991 Apple Users' Group, Sydney
Republished from Applecations, a publication of the Apple Users' Group, Sydney, Australia.
A heavy duty power supply for the Apple IIGS.
For some months, I had been having trouble with my GS. With the lid off, and the (noisy) fan on, I could only use the machine for about 20 minutes before I started getting the famous "Fatal System Error 911" messages. Inside the GS I had a Super Serial Card, Transwarp (7Mhz), Digitiser/stereo card, High Speed SCSI, and 4Mb of RAM.
The Apple power supply that comes with the GS is rated at 3.5 Amps. This is sufficient to supply enough power to the motherboard and a few cards. However, if you start adding some power hungry cards, such as the Transwarp and 4Mb, you will soon be requiring more power than the supply was designed for. This seemed to be the cause of the problem with my GS. A phone call to Jeff Shurrman at Two Series Software soon provided a fix for all my problems. Applied Engineering have a heavy duty supply rated at 7 Amps, almost double the Apple supply. Most of you will remember the hot whether around Christmas, what a great time to test the supply. I put the supply in the GS, took the fan out, put the lid back on, and away we went. The GS was on for 4 days, actively being used about 80% of the time, in temperatures up to 47 degrees (on an cheap, inaccurate thermometer!). During that time, the GS never hinted of playing up. After this marathon run, the power supply was too hot to touch, but higher temperatures are to be expected with a more powerful supply. Since, then, I have swapped my High Speed SCSI card with a RAMFast SCSI, a card that would draw more power (I assume), and the supply is still functioning faultlessly. The supply looks exactly the same as the Original supply, takes about 30 seconds to install, and has the provision on the side for the standard GS cooling fan.
The only problem I can see with the supply is that it is possible to connect the motherboard connector back to front. I have no intention finding out what happens, if you do this, but I suspect a new motherboard would be required. The connector on the original Apple supply has been designed so that you cannot connect it the wrong way. The AE supply doesn't have this safety feature. As long as you are careful during the once only installation, this shouldn't be a problem.
The supply comes with a 1 year warranty, and a useless, but unneeded American power cable.
My impressions of the supply? Great, I never sent the supply back, I sent a cheque instead.
Note: While the power supply fixed the problems I was having with my system, it may not fix any problems other people are having with machines.
An "exchange" Apple IIGS power supply is about $100 plus labor, the AE power supply is $190.00, and you keep the Apple supply as a backup. A worthwhile investment in my mind.
There is also a version for the Apple ][+ and //e
Review power supply from Two Series Software, (02) 606-9343

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