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Questions tagged [chs]

Cylinder-head-sector disk addressing: addressable range, direct use, compatibility issues and conversion between coordinate systems.

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11 votes
1 answer
2k views

How can I edit CMOS hard drive geometry settings on a 1991 PC?

First, I am NOT asking how to use the BIOS Setup utility. I'm asking how to OVERRIDE the built-in settings my BIOS Setup supports for the HD geometry. I have a 1991 NCR PC with a 386SX, on-board IDE, ...
Brian H's user avatar
  • 59.5k
9 votes
2 answers
2k views

How to determine BIOS-provided (INT 13h) hard disk geometry, and how to fix the MBR partition table to agree with it?

When transferring a hard drive from one computer to another, sometimes a situation can occur where the BIOS-provided CHS hard disk geometry (interrupt 13h without extensions) is different from the CHS ...
Alex Cannon's user avatar
7 votes
4 answers
716 views

Booting from SD card on a Compaq LTE 4/75 – DOS 6 works, Windows 95 doesn't

I'm in the process of restoring an old Compaq LTE Elite 4/75 laptop, which was missing its hard drive, so I thought I'd try booting using an SD-to-IDE adapter. On my main workstation I created an ...
Dmitry Brant's user avatar
18 votes
1 answer
846 views

How did Drive Overlay programs break BIOS disk barriers on older PCs?

I was just reading a thread on Vogons about OnTrack and EZ-Drive setup, and it occurred to me that I have no idea how they work. Please explain why the barrier existed and then how the overlay ...
Thraka's user avatar
  • 2,893
8 votes
2 answers
909 views

Compaq Contura Aero 4/33C - moving data to CF/IDE disk - No operating system detected

I've got a Compaq Contura Aero 4/33 laptop with original DOS system installed. As the HDD is old and dying, I've decided to copy the drive to a CF card on a CF/IDE adapter. After connecting the drive, ...
user905747's user avatar