How do I connect up an external 3.5″ IDE drive to the SX-1?
Make your own connector using the pinouts given in the manual. There’s no +12V supply on the 37 pin IDE plug, but you can wire in your own power supply or take the +12V supply from the floppy port instead. Always try Redmond Cable for your odd cable needs. Or make a 2.5″ to 3.5″ conversion cable, and wire in your own power supply. Conversion cables can be bought as part of A1200 3.5″ kits. Or you can buy a box (don’t know the name) from Hi-Q that sits in place of the SX-1’s lid. It lets you plug in 3.5″ IDE drives and it has a better power supply.