Had a bit of a disaster.
I picked up this ide Superdisk and tried it out first with a Mac Digital Audio running OSX where it worked perfectly.
Then I tried it with a MDT. No luck. Next I connected it to an Acard SCSI IDE bridge and my Ramfast seemed to know it’s there but wouldn’t mount the disk. Also tried an Apple Hi-Speed SCSI card. I’d tried this before with the mechanism from a USB Superdisk where it worked fine but not this time. I was a bit stumped so I put the Superdisk aside while I thought about it.
In the meantime I connected the CF adapter back to the MDT and got a message that there was no drive attached. I swapped over the one socketed chip and the CF adapter but it looks like the MDT is toast.
There’s also now an issue with the Acard adapter. It may be something I can live with or the board may be on it’s way out. If I power up the acard then the IIgs everything’s good. If I power down the IIgs then turn it back on without turning off the Acard then the media attached isn’t seen.
The Hi-Speed SCSI card I used also was dead. I have a couple of spares so I tried swapping the NCR53C80 and the dead one works. At least it wasn’t the custom chip.
I tried the Ramfast with a couple of drives and it seems good, fortunately
I’ve ordered another MDT and a replacement SCSI controller chip.
It’s strange that something that works on one set of hardware fries things on another
Check all of your power supply units and make sure they all have one common "thick" GND before PLUGGING them in the mains outlets. Don't count only on a common GND provided by the data cables. Switch the PSUs on before loading them with a lot of and valuable peripherals, and make sure all the voltages of each PSU with that common ground connected are within specs. If everything is within limits for several minutes, then switch off the PSUs and connect all devices to them, and then use them. If you could use one common PSU from a PC/XT for example (the good old bulky 150W generic PSUs) to power all the devices (incl. the //GS itself) that would be perfect.
The events described could also be ESD damage. It is nearly winter in the Northern Hemisphere and static is high.
I used different PSUs and had similar damage with everything.
I've also checked voltages, I have almost an OCD about that. Most of my power supplies have labels on them listing the voltages.
Labels are constant, output voltages are not.
I'm in the BC lower mainland. It's usually pretty humid.
I've tried the Superdisk after in the Mac and it's still working fine there.
The cables were all keyed.
I'd previously taken apart a USB Superdisk and I found an ide drive inside. I'd connected it to the IIgs via an Acard adapter and a Ramfast where it worked perfectly. Now the only visible difference between that one and the ide one was that the ide one had a faceplate. I may try that one and move the faceplate over. I'll likely be interested in seeing how the ide one works in the USB case.
There were multiple iterations of the LS120 drive with different performance and compatibility changes.