old timers computer tech help

[cubby1223]

Alright, I was presented with an ancient pc yesterday, ~20 years old. Battery went dead I assume, cmos does not retain any settings. They'd like the hard drive contents back.

The computer works fine, otherwise, but is one of those old systems where the bios has 48 preset hard drive parameters that I have to select one. When I started working with computers, it was at least when the established hardware had a user-defined mode. Used to carry around a big think book containing most all hard drive models with drive parameters and jumper settings. Glad those days are in the past.

Basically, I'd like to ask what happens if I select the wrong configuration in the bios?

The hard drive is ide, but new hardware just does not support them at all.

Just throwing it out for anyone who might recall any of the procedures from many years ago.

 

[oynaz]

Can't your modern IDE equipped mobo simply auto-detect it for you?

 

[jackschmittusa]

I still have my big thick book. PM me the make/model, and I'll look it up.

 

[cubby1223]

I found the drive parameters on the internet. Off the top of my head it's like 770 cylinders, 8 heads, 53 sectors/track, rll encoding (or something having to do with rll). The bios's first option is to select between MFM & RLL, the MFM being ~12 sectors per track, RLL being 26, which is odd considering the drive's actual parameters. But it might be something like what we used to do with the cylinders & heads, where you could double the heads & halve the cylinders because the bios could not handle such large numbers.

Anyways, the bios's presets are nowhere close to these parameters, and not sure what happens if I select a preset that's not the one that it was originally, if it just won't recognize the partition, or may screw up the partition table. So that's what I'm mainly wondering about, if anyone remembers. Personally, I'd prefer the sledgehammer approach...