Re: Restoring IIGS with Transwarp IIGS --> identification if loose IC

[Rubywand <rubywand@swbell.net>]

Dave Althoff Jr writes ...
> 
> Rubywand (rubywand@my-deja.com) wrote:
> : Dave Althoff Jr writes ...
> 
 ....

> Well, the board passed the thumb test.  A couple of days ago, prompted
> mostly by reading this newsgroup again, I installed the board into a
> 'spare' GS, hooked it up to the TV set, and let it run.  That is a 512k GS
> with a single 3.5" drive and the lid off; it's been running for two days
> straight now (basically just idling) and hasn't crashed or frozen yet.
> Most annoying since I was hoping to use the TWGS in my main machine...
 ....

     Not finding a flaw on the Transwarp does pretty well locate the problem in
your main IIgs.

 ....

> 
> The main machine first of all has a SCSI hard drive mounted in
> a Vulcan case...the Vulcan case has its own fan inside.  The machine also
> has a System Saver GS sitting on top...but the monitor is nowhere near the
> box.  The box is on a shelf under the desk, the monitor is on top.
> 
> :      Overheating may not be the real problem. It is not unusual for a
> : IIgs with a few Slot cards already installed to begin experiencing
> : system crashes after an accelerator is added. The culprit generally
> : turns out to be noise generated across skimpy power supply leads and/or
> : skimpy Slot bus power traces. For more about this and possible fixes,
> : see http://home.swbell.net/rubywand/Csa2POWER.html .
> 
> Now this is not only possible, it's likely.  My machine has...
> 4 Mb RAM card with piggyback for 1Mb Apple card (total 5.25Mb)
> Video Overlay Card
> Apple High Speed SCSI card
> 
> So there are a few cards in there.  Hmmm...I'll take a look at that web
> page...
 ....

     The fix is not especially difficult-- i.e. in the sense of having to do lots
of testing and adjustments. The main thing is having the stuff you need ready--
like some nice 14 gauge (stranded) wire in three colors to swap in for the power
supply +5V, +12V, and GND leads. (If your Vulcan drive includes a power supply with
heavy leads going to the motherboard, the lead swap may not be necessary. If the
design follows Apple's example, the leads will need to be replaced.)

     Adding the motherboard jumpers to Slots 3 and 7 is pretty easy, too. If you
use different colors for the recommended 18 gauge +5V, +12V, and GND jumpers, it is
not so hard to keep things straight and check you work. (Reinstalling the
motherboard is much easier if you rip out the bottom and back shields.)

     Anyway, since you want to run an accelerator in your main GS, there are not a
bunch of alternatives to fattening up the power busses.



Rubywand