On 22/06/02 at 23:36 Tony Firshman wrote:
>Another Eindhoven workshop has come and gone. >This one was memorable for: > ... > 4) Finding that a non-working returned Mplane was probably due to the > owner drilling holes through the pcb. This is a mite silly with multi-layer > boards (8-)# A mite silly with any board when you don't really know what you are doing, and it seems he didn't. Good thing the drill was pointed the right way, could have drilled a hole in his head. > 6) Seeing a pretty functional QDT alpha. It is going to be a very essential > addon to the QL. Pity Jim Hunkins is only coding for SMSQ. And VERY impressive. > 7) Severely testing a Super Gold Card. I have from time to time > connected expansions cobbled for 5v supply to a std QL, but only > briefly. ...All I can think is that the 8301 had latched (where signal > lines are higher than power rail and it had successfully kept the > SGC power rail much lower than 10.5 volts... but for 90 minutes? > Amazing. What think you Nasta? Chips are really much tougher than one would think. As for the latching theory, it is quite possible. When a chip goes into latch-up it essentially turns into a SCR, and the voltage across it's power terminals becomes about 1V or higher (if really considerable current is flowing). Even so, the 8301 would only have 'protected' the QL power as that is fed through the on-board 7805. But if it did latch up, at least it lowered the voltage some. Most of the stuff on the SGC is quite resilient - the 1810 comes to mind as the least resilient one. HC logic and RAM are quite good with overvoltage, so is the 68020. Bottom line: you were lucky :-) > BTW what on earth have you been doing in the US - eating Cow Pie (UK > Dandy readers will get the reference). Hm... the closest translation of 'Cow Pie' to the Croatian idiom would be the round flat pile of cow dung on the road. If that was the reference, I resent it :-) > I gather you are all muscle (8-)# Hm... that would make me a snail without a digestive tract? I suppose it would have certain advantages - though short, my life would be very much simpler :-). I know I have a stomach, it's been bothering me thw whole morning... no, wait, that's a ma muscle too. Lessee... I think I have a brain (a bit of recursion there...)? Honestly, I have been working out seriously (for the sake of mental health as much as physical, if not more, especially in the last 3 years) for the last 6 years. Not much change in the last two, so I suppose the only reason why no-one mentioned this before was because at the last occasions I wore more clothes? Nasta
