sandy@druxv.UUCP (BishSL) (01/02/86)
When you request a drive other than your default drive, you get the message: "Insert diskette for drive B: Strike any key when ready ..." Example: With drive C: (hard disk) and drive A: (floppy), "dir b:" generates the above message. Does anyone know where this error condition is handled? It is NOT part of the "critical error handler," as I had expected. I want to override the standard handler with my own. Thanks! --sandy bish, AT&T Information Systems --drutx!druxv!sandy --(303)-538-4717
rde@ukc.UUCP (R.D.Eager) (01/05/86)
In the case you mentioned (DIR B:) when you only have A and C - it isn't
an error so no wonder you can't catch it!
This is the result of the way DOS simulates two floppy drives on a
single floppy system (such as an XT). It "knows" whether the floppy
drive is working as A or B at any time; most times it's drive A. If you
reference drive B, it asks you to take the disk out of the drive (since
it's the "A" disk) and insert the disk you would have liked to be in
drive B if you had one.
Try DISKCOPY A: B: on an XT or similar to see a demo of this.
--
Bob Eager
rde@ukc.UUCP
rde@ukc
...!mcvax!ukc!rde
Phone: +44 227 66822 ext 7589bob@nbires.UUCP (Bob Bruck) (01/06/86)
In article <81@druxv.UUCP> sandy@druxv.UUCP (BishSL) writes: > > When you request a drive other than your default drive, > you get the message: > "Insert diskette for drive B: > Strike any key when ready ..." > > Does anyone know where this error condition is handled? This message is handled by the RAM resident part of the disk driver (alias "RAM BIOS" or "IBMBIO.COM" on your system disk). On a single floppy system, it pretends that there are actually two floppy drives, keeps track of which logical "floppy drive" was accessed last, and then instructs the user to insert the other floppy if necessary. This was a kludge to allow poorly written software (i.e. software that "required" two floppy drives) to run on the single floppy PC's. Hope this helps. Bob Bruck (hao | allegra | ucbvax)!nbires!bob NBI Inc. Boulder, Co.
glen@intelca.UUCP (Glen Shires) (01/08/86)
> > In the case you mentioned (DIR B:) when you only have A and C - it isn't > an error so no wonder you can't catch it! > > This is the result of the way DOS simulates two floppy drives on a > single floppy system (such as an XT). It "knows" whether the floppy > drive is working as A or B at any time; most times it's drive A. If you > reference drive B, it asks you to take the disk out of the drive (since > it's the "A" disk) and insert the disk you would have liked to be in > drive B if you had one. > > Try DISKCOPY A: B: on an XT or similar to see a demo of this. > -- YES...AND to override this handler with your own, simply install a device driver for disk B: -- ^ ^ Glen Shires, Intel, Santa Clara, Ca. O O Usenet: {ucbvax!amd,pur-ee,hplabs}!intelca!glen > ARPA: "amd!intelca!glen"@BERKELEY \-/ --- stay mellow
bob@nbires.UUCP (Bob Bruck) (01/10/86)
In article <174@intelca.UUCP> glen@intelca.UUCP (Glen Shires) writes: >> >> In the case you mentioned (DIR B:) when you only have A and C - it isn't >> an error so no wonder you can't catch it! >> -- >YES...AND to override this handler with your own, simply install a >device driver for disk B: > Which isn't so easy to do. PC-DOS supplies a driver for disks A and B, at least, and any installable drivers would be assigned letters higher than that. The only way I can see to do this would be to capture the INT 21 Dos calls. This isn't as far-fetched as it seems - the PC-DOS ASSIGN command does this. Given that, one could install a device driver as, say, drive D (after the fixed disk), and make it LOOK like drive B with the assign command. Bob Bruck (hao | allegra | ucbvax | ...)!nbires!bob NBI Inc. Boulder, Co.