Re: Apple IIgs random hardware crashing - any ideas?

[ToasterKing <toasterking@SPLATbigfoot.com>]

In article <3F85D838.8000206@apple2.com>, Ed Eastman <ed@apple2.com>
wrote:

> ToasterKing wrote:
> >While the CPU connector and cable on the TWGS could be at fault, I don't see
> >why the crashes would still occur when the TWGS is removed and the original
> >40-pin DIP CPU swapped back in.  
> 
> Oops, I skimmed that paragraph.  If the new socket went in and the 
> original CPU still causes crashes, then it is probably not the socket's 
> fault.  Net thing I'd check is the ram and the ram card slot connection. 
>   Make sure all the ram chips are seated properly and the card sits 
> firmly in the Ram Expansion Slot.  (shouldn't wobble even a little.)

I thought of that.  The crashing also reins after the memory expansion
card is removed.  BitBanger reports all of the RAM on my AE GS-RAM III
card as bad, but I'm told it's supposed to do that because BitBanger is
incompatible with AE memory cards.  But if the symptoms still persist
with no card in the memory slot, that's not the issue anyway.

> > BTW, I know that the TWGS does not have to be in any particular slot since
> > it only uses the slot for power to the
> > card (isn't that right?).  
> 
> I believe that the Transwarp is also monitoring the DMA line, but don't 
> quote me on that.  Looking at the slot cconnector and diagram of the 
> pin-out from the FAQ, it sure looks like it has DMA in and DMA out wires 
> along with the 5V and Gnd...  As well as a few others.  Whether or not 
> they are required, your gues is better than mine.

I actually powered up a GS once with a TransWarp GS connected to the
CPU socket, but the card not seated in a slot.  It did boot, it was
accelerated, the TransWarp CDA was functional, and everything seemed to
work fine.  I powered it down immediately though, since I realized I
was powering the whole card through the CPU socket and didn't want to
risk overloading traces or other damage.  So FYI, apparently it's not
required. ;-)

> > how long of a CPU cable have you made reliably?
> 
> Well with the standard 2-2.5" cable, I can reach slots 1, 2, 3, and 4. 
> But IDE cables (40 wire unchielded) carry signals a bunch farther than 
> that in most PCs. :)  Were you thinking about running a cable farther 
> than that?

I was just curious.  In my experience, the GS seems to be especially
sensitive to noise.  I've never considered it, but I suppose I could
run a 20-foot CPU cable and connect the card to +5V and GND in the next
room to see if it works, but that would just be silly.

Thanks again for the tips on making the cable.

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