I'd imagine it's worth much more than a used one because a big part of a drive's reliability is Power On Hours. If the drive has zero POH, it should be more valuable than a drive with 50,000. So, if you're looking for a reliable drive, you have it (assuming no physical damage of course).

edit: not sure about drives of yesteryear, but nowadays, 50,000 POH is considered "end of life" and people recommend retiring such drives because the probability of failure goes up exponentially.

In older DOS 6.22 systems 2GB or so is the practical limit, though SCSI drives and controllers might need to be use depending on the motherboard.

I'm looking for an older SCSI 2GB drive myself and there are several listed at over 100 USD on eBay used. I'm in no rush really though.

Cheers.

WR3ND wrote:

In older DOS 6.22 systems 2GB or so is the practical limit, though SCSI drives and controllers might need to be use depending on the motherboard.

Depends on the BIOS, really. 524Mb, 1Gb, 2Gb, 8Gb (in four 2Gb partitions) depending on the system. Most contemporary SCSI controllers had a 1Gb or 8Gb limit.

WR3ND wrote:

In older DOS 6.22 systems 2GB or so is the practical limit, though SCSI drives and controllers might need to be use depending on the motherboard.

This is the FAT16 limit. The true upper limit depends on the BIOS. I'm also curious as I haven't tested this, how many logical drives can DOS 6.22 create and use on one single HDD?

gdjacobs wrote:

WR3ND wrote:

In older DOS 6.22 systems 2GB or so is the practical limit, though SCSI drives and controllers might need to be use depending on the motherboard.

This is the FAT16 limit. The true upper limit depends on the BIOS. I'm also curious as I haven't tested this, how many logical drives can DOS 6.22 create and use on one single HDD?

For DOS, you can have:
- max. 4 primary partitions
- unlimited number of logical partitions on an extended partition (of course you will be limited to available letters in English alphabet 🤣)
- max. 8GB total of partitioned space on a single HDD.

There is a nice discussion related to the subject:

http://www.msfn.org/board/topic/159631-testin … os-limitations/

Just to clarify, this is a kernel limit on supported HDD geometry, not just an issue with FDISK?

gdjacobs wrote:

Just to clarify, this is a kernel limit on supported HDD geometry, not just an issue with FDISK?

No, nothing to do with Fdisk. There are many different partitioning utilities around for DOS but the limits are the same (and I'm talking about version 5 or above) and not related to partitioning software. Except, Fdisk cannot create more than one primary partitions on a single disk, so you need to use something else.

Time finally caught up with MS-DOS 6.22. I guess I need to finish a PC-DOS 7.1 install procedure, then!