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Testing a couple of IBM DCHS (68 pin) 4.5 GB SCSI drives


Well-known member
Hi all. Got a decent deal on these two HDs. They arrived physically well, but with marginal packing :(

Anyway, I formatted them (not low-level) using the patched version of Drive Setup 1.5 -- I did it first on the SE/30 running 7.5.5. Aware of the problems of large volumes with older Macs, I decided for the following partition scheme:

Disk 1: one small (circa 200 MB) partition, then two partitions a tad below 2 GiB (2047 MiB each)

Disk 2: one small partition (about 300 MB) and a large one (4000 MB)

On each disk's small partition I copied, as is, the running 7.5.5 System folder (installed for any Macintosh). This is not the main issue here, but no matter how I try (Startup Disk control panel, System Picker, key combos...) the SE/30 won't boot from it, reverting quickly to the internal HD... but the disk mounts fine after booting.

On the other hand, my 7600 with G3 card boots perfectly from this very same disk with the very same System software! Maybe the driver installed by this version of Drive Setup (8.0.9, if memory serves) is not suitable for booting a 68030 machine? I may try the patched HD SC setup instead...

But here's the original question: once on the 7600 booted from another HD, I issued Drive Setup's Test Disk command on my newly purchased IBM drive, but after a few minutes the test was ended upon an unrecoverable error :?: I then reformatted the disk low-level, to no avail. Then I went for Formatter One Pro and its Non-destructive test giving similar errors. After reformatting with that tool as a single, large partition, the test lasted much longer but was eventually aborted by the unexpected error xx(

But prior to bashing the seller }:) I did another test: filled the disk with several, largish DiskCopy read-only images with checksum -- they all mounted perfectly which, as far as I know, means it could read every single byte in order to compute the checksum, and they were read well.

So... can I deduct that the disks are actually fine, but the test got interrupted somehow?

Thanks a lot in advance,



Well-known member
Connect them to a PC using native 68 Pin cables and then use Seatools or another utility to run a full test.

Some UW drives don't like working in 50 pin mode or have a jumper on them to run in SE (single ended mode), you might also have an issue with termination.



Well-known member
Many thanks to all for your help.

But now I think it was all termination issues or some other sort of SCSI-voodoo... I have checked again the disks on my recently acquired LC 475 (by the way, what a nice, snappy, tiny, versatile, underrated machine it is!) with the very same patched Drive Setup, and they check just fine! Ditto on the SE/30 (took about 3 hours!)

On the other hand, I tested the known-good Conner in daily use on the 7600/G3... and each time different errors show up :-/ I initally chose this machine because of obvious performance reasons, but in its current state it may not be the ideal setup for full function:

7600 mobo + PSU + 604/120 MHz card (now backup) + fully populated VRAM + 64M RAM = 3 EUR. The G3 @ 450 was a whopping $20. It feels so fast... :D



Well-known member
Yea, the LC475 is a peppy little machine. I am restoring one for a youtube friend.

Hell, it even handles realbasic compiling, debugging, and running full applications without issues, Just the occasional TYPE errors in the IDE, but i think that has more to do with OS8 than anything else.