Identifying a really old file system

[Moon_man157]

I have an old hard drive. The date codes on some of the chips seem to suggest 1994 or 1995 as a year of manufacture. I have a IDE to USB adapter. My computer can see the drive but says that it's unformatted and needs to be initialized. I'm thinking that perhaps it doesn't use a standard file system like FAT 16 or FAT 32. Can someone suggest an application or method for identifying what file system might have been used for this drive? I'm hopeful that one's I determine the file system I'll be able to find some emulation software to help me access the drive.

[lcoughey]

Can you show the first few sectors in a hex editor? You can use Winger, R-Studio, UFS Explore or some other data recovery software that has a built in hex editor

[Moon_man157]

This is the first three sectors of hex. It makes a reference to "MICRO HOUSE INTERNATIONAL" do you know what that is?

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

[lcoughey]

I was hoping that you would have posted something a little easier to read, like this:

sectors-in-hex-editor.png (72.79 KiB) Viewed 7016 times

[lcoughey]

This is your data in a Hex Editor. Take note of the circled text showing that Overdrive was being used. As it has been so long ago, I'm fuzzy on Overdrive, but do believe it was a wrapper which tricked the BIOS in accessing a drive that is larger than what it was designed to access.

sectors-in-hex-editor-1.png (904.51 KiB) Viewed 7016 times

[lcoughey]

Based on this (https://www.atarimagazines.com/compute/ ... peedup.php), perhaps I'm off on the purpose of Overdrive.

[Joep]

I see 0E partition in table which basically is FAT16.

Can you try open partition in DMDE (www.dmde.com)?

[fzabkar]

I used similar applications years ago. Most HDD manufacturers had Disk Drive Overlays (DDO) which enabled older systems to circumvent the 528MB CHS capacity limit. Sector 0 would contain a dummy partition table which would allow the BIOS to boot the code in the MBR, and this would then install BIOS INT13 extensions. The real MBR and partition table would be elsewhere, usually somewhere within the first few sectors, and that's what DOS would see.

I believe sector 1 contains the real MBR with a single FAT16 partition at LBA 63 (0x3F).

Sector 0 points to a boot sector at LBA 17 (0x11). That's most probably a dummy. CHS drives typically had 17 sectors per track.

The partition ID is 55h -- "EZ-Drive, Maxtor, MaxBlast, or DriveGuide INT 13h redirector volume (MicroHouse / StorageSoft)".

https://en.wikipedia.org/wiki/Partition_type

Here is standard MS MBR code prior to Win95:

https://thestarman.pcministry.com/asm/mbr/STDMBR.htm

It corresponds to LBA 1.

The size of the partition corresponds to an 850MB drive.

I should add that USB-IDE adapters probably don't know how to deal with CHS HDDs, although I expect that 850MB HDDs did support LBA mode.

[fzabkar]

Code: Select all

 LBA:0                  block: 0
 Disk identifier (Windows):
 00006C27h
 Boot  System ID   :   First    :    Last    : Relative : Number of:
 Flag              :Cyl Head Sec:Cyl Head Sec:  Sector  :  Sectors :
 80h 55h ??        :   0   1  1 : 915  14 17 :        17:   1661121:   850 MB
 00h 00h           :   0   0  0 :   0   0  0 :         0:         0:        0
 00h 00h           :   0   0  0 :   0   0  0 :         0:         0:        0
 00h 00h           :   0   0  0 :   0   0  0 :         0:         0:        0
 MBR signature (0xAA55):
 AA55h

Code: Select all

 LBA:1                  block: 1
 Disk identifier (Windows):
 00000000h
 Boot  System ID   :   First    :    Last    : Relative : Number of:
 Flag              :Cyl Head Sec:Cyl Head Sec:  Sector  :  Sectors :
 80h 06h FAT16     :   0   1  1 : 823  31 63 :        63:   1661121:   850 MB
 00h 00h           :   0   0  0 :   0   0  0 :         0:         0:        0
 00h 00h           :   0   0  0 :   0   0  0 :         0:         0:        0
 00h 00h           :   0   0  0 :   0   0  0 :         0:         0:        0
 MBR signature (0xAA55):
 AA55h

[lcoughey]

Thanks Franc...I was distracted by identifying the front end wrapper, I forgot to finish the analysis, though your is more thorough than what I would have provided.