MSCSUB - MSCDEX Substitute, (C) Colin King, cik@ukc.ac.uk, 15/03/93

             Copyright Colin King/Templeman Library, UKC

	This software can be freely distributed as long as this 
	documentation is bundled with it and as long as the
        author gets credited for the work. Any modifications to
	the source code should be forwarded to the author.

			     DISCLAIMER

	The author is not responsible for any damage caused from
	the use or misuse of this software. (The author doubts that
	anything can be damaged using this software!)
  
		---------------------------------------

  MSCSUB is a TSR that attempts to emulate MSCDEX for CD Drives mapped
  onto a PC via NFS.  It cannot emulate raw I/O functions such as
  read/write, nor can it emulate device operations, such as ejecting/locking
  CD rom drives. MSCSUB has been tested on 386 and 486 PC's and should
  support 286's, but has not been tested.

  MSCSUB Supports 26 drives, from A to Z, but most users will use
  drive D up to Z since A..C are usually reserved for system disks.
 
  MSCSUB now emulates the following MSCDEX subfunctions:

 	00h	Get Number of CD ROM Drives
 	01h	Get CD-ROM Drive Device List
 	02h	Get Copyright File Name
 	03h	Get Abstract File Name
 	04h	Get Bibliographic Doc File Name
 	05h	Get VTOC (partially emulated - not sure if okay)
 	06h	Turn Debugging on 
 	07h	Turn Debugging off
 	08h	Absolute Disk Read - Emulated to return error 21
 	0ah	(Reserved)
 	0bh	CD ROM Drive check
 	0ch	MSCDEX Version 
 	0dh	Get CD Drive Letters
 	0eh	Get/Set Volume Descriptor Preference

  MSCGET and MSCMOD are auxiliary programs for configuring MSCSUB whilst
  it is memory resident. This allows MSCSUB to be tailored for each
  individual application without the need of reloading.


  MSCSUB Loading.

	MSCSUB is a TSR. It is loaded in the same was MSCDEX is. It can
  be placed in high memory using LOADHIGH MSCSUB.

  MSCSUB Syntax:

	MSCSUB drive ...

  Eg:
	MSCSUB D E F K O
		loads MSCSUB for drives D, E, F, K and O

  

  MSCMOD
	MSCMOD is used to modify the configuration of MSCSUB whilst
  MSCSUB is in memory. MSCMOD makes use of MSCDEX reserved function
  ffh to communicate to MSCSUB. MSCMOD can be used at any time to
  configure or reconfigure MSCSUB.

  MSCMOD Syntax:
	
	MSCMOD -a drive ...	Add drives to MSCSUB
	MSCMOD -r drice ..	Remove drives from MSCSUB
	MSCMOD -v version	Modify MSCDEX version number
	MSCMOD -moff		Turn off MSCSUB
	MSCMOD -mon		Turn on MSCSUB if turned off
	MSCMOD -name MSCxxxx	Set name of device driver to MSCxxxx
	MSCMOD -file fname	Set name of data file to fname for
				functions 02h, 03h, 04h


  Eg:
	MSCMOD -a J K P		Add drives J, K and P
	MSCMOD -r P K		Removes drives P and K
	MSCMOD -v 0210		Set version to 2.10
	MSCMOD -name MSCD002	Set device driver name to MSCD002
	MSCMOD -file C:\DATA\MSCSUB.DAT

  
  Functions 02h, 03h, 04h.

	To emulate these MSCDEX functions, MSCSUB grabs the data for these
  from an auxiliary data file that you must create before hand. By default,
  MSCSUB expects the information to be held in a file called MSCSUB.DAT,
  but this can be changed using the MSCMOD -file command.

        To create the datafile for these functions, you need a CD ROM drive
  locally connected to your PC running the real MSCDEX. Do not install MSCSUB 
  at all.  Run MSCGET, this gets the MSCDEX 02h,03h,04h returns
  from the CD and stores them in a named datafile. 

  MSCGET Syntax:

	MSCGET -v	  Runs verbose mode - shows some CD Rom information.
	MSCGET -g fname	  Get 02h,03h,04h information, put it in file
			  called fname.

  For example, suppose we have 2 local CD drives, D and E, and we want the 
  information into file C:\INFO\EXAMPLE.DAT

	MSCGET -g C:\INFO\EXAMPLE.DAT

  File C:\INFO\EXAMPLE.DAT will contain something like:

	1502
	D:xxxxxx
	E:xxxxxx
	1503
	D:yyyyyyyy
	E:yyyyyyyy
	1504
	D:zzzzzzzz
	E:zzzzzzzz

  Where xxxxxx is the Copyright information (02h), yyyyyyyy is the Abstract
  information (03h) and zzzzzzzz is the Bibliographic Doc information (04h)
  for drives D and E respectively.  Now we have the information in a
  file, we can tell MSCSUB where to pick up this information once the
  CD's are mounted on NFS.

  Suppose you want these 2 CD's mapped onto NFS drives J and K respectively.
  Edit the file to change D to J and E to K for each entry.  Mount the
  CD roms and run MSCSUB. Let MSCSUB know the name of the file that
  contains the information, eg: MSCMOD -file C:\INFO\EXAMPLE.DAT

  MSCMOD allows you to change the name of the file at any time, so you
  can dynamically change the configuration dynamically, from one database
  to another.

	If this documentation is too brief or not good enough, send
  you gripes to me, cik@ukc.ac.uk.