[comp.os.msdos.apps] MS-DOS 5.0 and CD-ROM --> SOLVED!

wiggins@zodiac.rutgers.edu (06/27/91)

In my earlier posting I said the following:

>Hi!

>I hope someone can help me out. I Just upgraded to DOS 5.0 from DOS 4.01
>on my 386SX clone. My problem in a nutshell is that now DOS wont recognize
>my CHINON CDS431 CD-ROM drive.

>You can attach to the drive, but when you try to perform any IO such as
>DIR, DOS returns "Invalid Drive."

>The drive worked well under DOS 4.01, and I have changed nothing else besides
>the OS. My MS CDROM Extensions are version 2.10. Do I have to upgrade my MSCDX?

As it turns out, I caused the trouble. Here is what happened:

	My system is a 386SX clone.
	I am using QEMM 386 5.11 and loading device drivers high.

	With QEMM 5.11, you have the ability to load LASTDRIVE high
	by doing the following:
		
		Enter LASTDRIVE=E (or some other low letter) in
		CONFIG.SYS, and enter LOADHI LASTDRIV Z somwhere
		in autoexec.bat.
		This puts the Drive information for F thru Z into upper
		memory, and frees up lower memory.

	My chinon CD-ROM is assigned  drive letter L:, and the driver
	for the CD-ROM, CHINON02.SYS, is loaded AFTER LASTDRIVE=E but
	BEFORE Quarterdeck's LOADHI LASTDRIVE Z:.

	Interetingly enough this situation did NOT cause any problems
	under DOS 4.01 although it is completely eroneous.

	However I haven't gotten to the part where I made even dumber
	moves.

	THE MS-DOS 5.0 installation program had actually CORRECTED this
	clearly incorrect configuration by inserting LASTDRIVE=Z before
	my DEVICE=CHINON02.SYS line in CONFIG.SYS.

	But in my infinite wisdom (har har) I was irate that the
	DOS 5 installation program had decided not to let me load drives
	F thru Z high using QEMM, so (without checking to see if
	everything was working correctly) I changed the corrected
	LASTDRIVE setup to the old configuration (which was WRONG.)

	So with CONFIG.SYS newly botched, drive L: was NOT a valid drive
	when the CHINON02.SYS device driver attempted to assign itself
	drive letter L.

	It was at this point that I discovered that the CD-ROM drive didn't
	work.

	After mulling a few days over my problem, it occurred to me what
	a stupid thing I had done, and sure enough, after going back to
	the DOS 5 version of CONFIG.SYS, everything began working fine.

	There are a few things that the Microsoft bashers out there
	should know:

		1) Microsoft CD-ROM extensions work FINE without
		upgrading.

		2) Microsoft employees responded promptly by email with
		suggestions.

		3) THE INSTALL PROGRAM CORRECTED MY MISTAKES!!! (how
		many install programs have done that for you?)

		4) Microsoft included MSCDEX in the version table for
		SETVER.

	This Version of DOS is GREAT! (my brain is the next thing that I
	should upgrade).

	Thank you everyone for all your help!