The Sinclair QL Forum

RWAP wrote:Excellent news Good job it wasn't a SGC - they tend to be irreparable if plugged into a QL with the 5V regulator bypassed and no backplane.

I wonderif there are any figures for how many Gold and Super Gold Cards were ever made - presumably hundreds if not thousands out there SOMEWHERE!

With reagards to the shorted links on the Supergold Card MC68EC020 CPU. If you look at the datasheet for the CPU. There are the following )common lines adjacent to each other:

Pin 3-4 GND
Pin 7-8 Vcc
Pin 20-21 GND
Pin 58-59 GND
Pin 68-69 GND
Pin 70-71 Vcc

This would explain the shorted link on the CPU.


Derek

Those are the four ground areas, yep....but geeze, it looks like someone went at this thing with a shovel bit, a half gallon of solder and two gallons of flux!

After learning from Nasta's recent enlightening posts, I now understand what is wrong with this SGC. After a period of use, video corruption occurs. After writing a little routine to read out the middle lines of video RAM and print them elsewhere on screen as a value, I can see the SGC's copy of video RAM that it reads from is unaffected, so the problem is in the writes to the QL's memory. It's not pretty, but it's a relatively harmless bug.