In my experience with hard disk drives over the last 20 years, the Conner 850 MByte (CFS and CFA) hard disk drives rank low, but certainly not the lowest, for reliability. I would be hesitant to install an old one in any computer. Conner was bought by Seagate sometime ago. The older Quantum drives were made back in the days when implementation of the IDE specification (which Quantum invented) varied quite a bit from manufacturer to manufacturer. I do not remember the exact details, but some of the 40 and 80 MByte 3 ˝” half-height drives would not operate as slaves to drives made by some manufacturers. The low profile 170 may have compatibility problems as well, but I do not recall one way or the other. When jumpered as the Master drive, some of the old Quantums would operate with some drives made by other manufacturers when those drives were configured as Slaves. Furthermore, Quantum drives behaved differently when the old Quantum IDE expansion board was used as compared to those made by other manufacturers such as Seagate. Again, I do not remember the exact details, but may be able to find them in old repair sheets. Maxtor bought Quantum’s disk drive business a short time ago.
To use the full capacity of the Conner drive, the motherboard BIOS has to be capable of and configured to use Logical Block Addressing (LBA) (http://support.microsoft.com/support/kb/articles/Q122/0/52.ASP) or a BIOS overlay such EZ drive or Disk Manager has to installed on the C: drive. LBA or the overlay allows IDE disks with more than 1024 cylinders to be fully partitioned by MS-DOS/Windows. Without drive parameter translation provided by these capabilities DOS/Windows cannot use more than 504 Mbytes of the capacity provided by larger hard disk drives. Check the motherboard CMOS Setup to see if it can do LBA. Older boards with the capability may have the capability as one of three choices. Many have a hard disk detect capability, which may automatically choose LBA. Newer boards should have the drive set to Auto and that should implement LBA. If an overlay is required, the drive is usually set to Type 1, but not always.
Now that I’ve provided some background, the first thing to do is determine the motherboard’s capabilities. What motherboard do you have (see http://duxcw.com/digest/Fromshop/mb/det.htm)? How many IDE interfaces does it have? Larry