Telling (MS)DOS about a second floppy drive...

Jules Richardson julesrichardsonuk at
Fri Mar 10 11:06:04 CST 2006

Liam Proven wrote:
> On 3/10/06, Jules Richardson <julesrichardsonuk at> wrote:
>> Instead of using drive letters, it uses drive numbers - so according to the
>> docs 0 would be A:, but 1 could either be B: if a second drive was found, or
>> C: if it wasn't.
>> Got horribly confused at that point, decided that I didn't want a messed-up
>> hard disk if the B: drive wasn't seen, and kicked the machine. :-)
> Oh, no, it wouldn't do that. Hard drives are addressed totally
> differently & there'd be no confusion unless you told
> drivparm/driver.sys to use drive C: - not sure what would happen then!

Yes, it didn't say in the help how device numbers were translated to actual 
drives though - last thing I wanted was DOS thinking my hard disk had 80 
tracks and suddenly crashing when booting :-)

I'm not quite sure why it uses a device numbering scheme, when the device 
numbers can change depending on what hardware's attached (mind you I have no 
idea what happens if you were to add a second floppy controller say - whether 
drives 3 and 4 become devices 2 and 3, or if they follow on after and hard 
disks (and become say, 3 and 4 in a system with a single hard disk)

The relationship between the numbering and the physical devices wasn't 
documented :-(

>> I've gone back to a previous system now which has a sensible BIOS (and
>> on-board SCSI and audio, which may be handy for other data recovery stuff
>> anyway). Shame the case is huge, but at least there's room for four 5.25"
>> devices, and I could probably shoehorn an 8" drive on it's side in there too
>> if needs be with a bit of hacksaw work!
> Eeeesh. Good luck!

Heh heh. It'll be far easier for me to hang the 8" drive outside the case - 
but *technically* there is room for it to fit inside providing I relocate the 
hard disk and don't use any large expansion cards...

Ultimately I want to get rid of the hard disk anyway, and boot from something 
like compact flash - as control and actual storage for disk images would be 
external to this box with the floppy drives in, there's no need for any actual 
large hard disk in the machine. All I need is OS + disk + network access code 
to come from *somewhere* (possibly even ROM I suppose)



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