LBA

[[e-mail]]

I vaguely recall (from circa 1990) configuring my BIOS
to say what cylinders/heads/sectors I wanted my hard
disk to be.

Why was the end user involved in doing that?

Thanks. Paul.

[JJ]

Post by ***@gmail.com
I vaguely recall (from circa 1990) configuring my BIOS
to say what cylinders/heads/sectors I wanted my hard
disk to be.
Why was the end user involved in doing that?
Thanks. Paul.

I think it's because, while harddisks has been around for quite some time at
that time, the ATA standard didn't exist yet. At that time, harddisks are
using proprietary controller via expansion card. Or a hard-card where the
harddisk is attached directly on the expansion card along with the
controller. So, there's not yet a common software API for accessing
harddisks. BIOSes only support one brand & model of each supported hardware
component type. It's not practical to include code to support various
hardware brand and models, where in the end, only one or two are used. It
would be a waste of the already limited BIOS chip storage capacity.

[a***@math.uni.wroc.pl]

Post by ***@gmail.com
I vaguely recall (from circa 1990) configuring my BIOS
to say what cylinders/heads/sectors I wanted my hard
disk to be.
Why was the end user involved in doing that?

Early discs did not have command to read needed info from
the drive. Testing was problematic as on 1990 drives
cylinders/heads/sectors was really fake and on some drives
first access determined translation used by drive.
I do not know when exactly, IIRC around 1995 reading
parameters from drives was reasonably reliable (but
purely manual setting was an option for old drives).

[Joe Monk]

Post by ***@gmail.com
I vaguely recall (from circa 1990) configuring my BIOS
to say what cylinders/heads/sectors I wanted my hard
disk to be.
Why was the end user involved in doing that?
Thanks. Paul.

Well, if you remember, there were three proprietary standards back then ... MFM, RLL, and ESDI.

They all used different low level formats.

So, the BIOS was involved in translation from the proprietary format to the DOS standard format. Since the bios had no clue of the actual format, you had to tell it the translation parameters.

Joe