    If you have the older Mitsumi LU002 drive and would like a Dos
driver for it that is improved in its memory usage and speed, you
may be interested is this.
    I have found that the Mitsumi V2.10 driver will work very well
with the older 002 drive with a very minor patch.  I will detail
this patch below:

OFFSET      WAS      CHANGE TO
------     -----       -----
0EC9        E8          B0
0ECA        73          FF
0ECB        30          90
3A93        E8          B0
3A94        A9          FF
3A95        04          90

    You can use a debugger or binary file editor (like FED) to make
this patch to the Mitsumi driver MTMCDE.SYS V2.10.  I have found the
new driver to work perfectly with this patch on my older drive.  This
driver is actually intended for the newer LU005 drive, and Mitsumi says
that this driver will not work with this drive.  I have found that this
patch will fix this problem and allow its use with same.  I am not
connected with Mitsumi in any way, so don't look to Mitsumi for any
support for your experiences.

    The benefits of the new V2.10 driver over the older V1.50a driver are:

1)  The X switch to allow XMS buffers GREATLY reduces memory demands!
    You can have up to 64 buffers in XMS and only about 20k of conventional
    or upper memory will be used for the driver itself, compared to over
    80K used with MTMCDD.SYS v1.50a with 32 buffers!!!

2)  Boot up driver load-in time and disc change time are speeded up.

3)  CD benchmarks show a very slight speed gain.

    Where do you get the new driver?  Good question.  Mitsumi does NOT
have a support BBS, nor is it representing itself on Compuserve to my
understanding.  You may be able to find the new driver on a local BBS
as it is floating around as a patched "bug fixed" version.  It is
presently on the following BBSs, and probably many others:

    Midas Touch    IL   (312) 764-0761     ;In a door
                        (312) 764-0591
    7 Keys BBS     NY   (914) 747-2836     ;In the FREE door

    Apply this patch ONLY to MTMCDE.SYS V2.10.  Then refer to MTMCDE.SYS
instead of MTMCDD.SYS in your config.sys file.

-John Oliger    5/93
Compuserve ID# 74670,1675

************************************************************************
         UPDATE..........5/26/93!!!!!!!!!
************************************************************************

    The Mitsumi V2.10 driver is now in this forum on Compuserve under
the name of MD210B.ZIP!  THIS driver is slighly newer than the one
referred to above, so you will need to patch slightly different locations
to use it on your LU002.  I will detail the locations below.  (These offsets
are from the begining of the file, not where it may be loaded with a debugger.
You might need to add 100H to these numbers to get the correct address
as shown on a debugger.  If the "was" bytes match, you can bet you've
found it!

OFFSET         WAS        CHANGE TO
------        -----         -----
0E32           E8            B0
0E33           F9            FF
0E34           30            90
3A46           E8            B0
3A47           E5            FF
3A48           04            90

    I would like to thank whomever uploaded this file for us to Compuserve,
especially if Mitsumi doesn't mind!  (Why should they, we DID buy thier
drives, didn't we!  But there IS the copyright stuff...)

-John Oliger

