Cannot partition ST-251 hard drive to 1 partition of 42 MB.

[Bill-kun]

The Dell System 200 that I unearthed in my parents’ basement in September 2020 has a Seagate ST-251 hard drive. According to the file dates, the last time anyone used the drive was June 1994. The drive was partitioned into a primary DOS 31 MB. and an extended DOS 8 MB. (This accounted for all the 42 MB. space, according to FDISK.) I don’t know why those partitions were the sizes they were. Both partitions were perfectly usable.

Tonight I deleted the partitions using FDISK, and tried to create a single partition of 42 MB. FDISK keeps telling me that the maximum size available is 31 MB. I used SpeedStor and did a scan, added the few bad sectors that came up to the defect list, and did a low-level format. Still, FDISK keeps telling me there is only 31 MB. available. Just before I did the deletion of the 8 MB. partition, I tried doing a dir on it, but DOS gave an error. So I decided to finally repartition, which I had been planning to do for weeks.

I am using DOS 6.22 and SpeedStor 6.5.

 

[maxtherabbit]

are you sure the binary of FDISK you have is the one from DOS 6.22? because that sounds an awful lot like the old DOS 3.3 32MB limit

 

[alank2]

I just ran into this too - MS-DOS 3.30 limitation on partition size.

 

[Bill-kun]

The hard drive did have DOS 3.30 on it. I am using DOS 6.22 from a bootable floppy disk for FDISK.

How do I get around the partition size limit? What “binary” do you mean?

 

[maxtherabbit]

DOS consists of both "internal" and "external" commands. Internal ones like DIR, COPY, etc. are built into the command processor. External ones like FDISK require their own executable file. Using SYS (also an external command btw) to make a boot disk does not transfer any of the ancillary DOS command files like FDISK, FORMAT or even SYS itself to the target disk.

Short answer you need to copy FDISK.EXE from a fully installed DOS 6 system to your boot disk

 

[Timo W.]

Or even simpler: delete all partitions and boot from the DOS 6.22 install floppy. It will detect that there's no partition and does all the work for you.

 

[Bill-kun]

Or even simpler: delete all partitions and boot from the DOS 6.22 install floppy. It will detect that there's no partition and does all the work for you.

I already had deleted all the partitions on the hard drive. I am already using FDISK from the DOS 6.22 boot floppy. It won’t let me run an edition of FDISK that doesn’t match with the DOS boot version. For example, after booting in DOS 6.22 I can try to switch floppies to DOS 6.20 to run FDISK and it will respond only with “Incorrect DOS version.”

I don’t have a DOS 6.22 install floppy, if that is different from a normal boot floppy. I made my DOS 6.22 boot floppies from www.bootdisk.com.

 

[Bill-kun]

Oh, good grief. The solution was to unplug the secondary physical hard drive. Even though it wasn’t conflicting, and even though the failure mode has no sensible relation to the cause, somehow it was and somehow it did. Picky, picky, picky, Computer.

Once I unplugged the secondary hard drive and rebooted with the DOS 6.22 floppy, everything worked fine. I repartitioned the primary drive with all 40.23 MB. in one partition, rebooted, and used “format c: /s” and everything was as smooth as Zaphod Beeblebrox.