The Sinclair QL Forum

I just acquired a Miracle Systems SGC and companion dual 3.5 ED floppy drives. The SGC is working great (so it seems) but I'm having difficulty with the disk drives. Basically, the cables to/from drives and SGC is connected, looks clean (no breaks), and the disk drives are receiving the requisite 5V DC from the Miracle Systems power supply. When the QL boots/resets, there is a very brief instant when one of the drives sounds as if its motor is going to spin up -- but the rotation stops shorts. Dir FLP1_ and Dir FLP2_ return "Not Found" messages after 10-15 seconds or so. MDV drives work fine.

I'm wondering if there is some sort of toolkit command or extension I'm supposed to use to ensure the drives are recognized by the SGC and the SGC is sending/receiving signals to the drive.

Any thoughts on that? Also, anyone have experience using a more recent (off the shelf) IDE floppy drive as a substitute for the original Miracle System drives? My understanding is that there is some issue regarding the need for a twisted cable to connect and use two floppies. Were I to use just one 3.5" HD IDE floppy with the existing Miracle Systems cable, would the drive be recognized at all?

Many thanks!

The command to try with the ED disk drives could be FLP_JIGGLE 1

That was sometimes needed on the SGC, although not normally with the Miracle Systems disk drives.

Also are you sure you have the cable connected to FLP1_ and not FLP3_ (the FLP1_ / FLP2_ connector is the one nearest the QL).

The biggest danger is that the drive heads have been damaged - ED disk drives should ALWAYS be shipped with a piece of card or a disk inside them, as there is a danger that the heads get knocked (much as you used to have to do with the old 5.25" disk drives).

You should be able to use a PC disk drive with the SGC - BUT start with a straight cable (untwisted). That should work if you connect the drive as FLP3_ or FLP2_.

The problem comes when trying to connect a modern PC drive as FLP1_ - because they are factory set up as a slave drive (not master). Some drives have jumpers to allow you to set them as DS0, or you might find a solder pad. Other than that, you need to swap pins 10 and 12 on the floppy cable - see:

http://theqlforum.com/viewtopic.php?f=11 ... rt=10#p584

Rich,

Thanks so much. You diagnosed the issue perfectly: I had the ribbon cable incorrectly attached to the FLP3 connector. Moved to the other connector and everything is working!

Tom