well according to amiga-hardware.com:
Hard Drive unit which connects to the expansion slot of the A500. Early units originally had an IDE Controller only, however with later units you could add SCSI. The IDE controller contained in this expansion is actually the same as those found in the A600/A1200 and A4000. The controller is not DMA but supports up to an additional 8MB of RAM by the use of 1MB 30pin SIMMS.
So is it possible you have the IDE only version? Are you trying to connect a SCSI or IDE drive?
