Hard-drive diagnostic program

I cna think of at least 4 categories of machines : 1) Those with an 8 or 16 bit ISA bus. For which there are solutions, like the XT-IDE + CF card 2) Machines that require an ST412-type drive, but can take any geometry, and will use all of it. 3) Machines that have a limited number of differnet geometries they can use, but don't check the drive carefully. If the drive has more heads/cylinders that the machine thinks it should do, the machine doesn't use all the disk space, but it does work 4) Machines that require one of a limited numebr of geometries, and check the drive to make sure it matches. If the selected gheometry says 4 hears, and the drive has 6, the machine will not use said drive. The last are by far the worst to find replacement drives for... -tony