Category : Alternate Operating Systems - Quarterdeck DesqView, CP/M, etc
Archive   : QOSTNOTE.ZIP
Filename : ATTPAT.TEC

.MB13
.PO12
DESQVIEW 2.0 PATCH FOR AT&T 6300

DESQview 2.0 on an AT&T 6300 with BIOS versions prior to 1.43 bombs when
going into DESQview. The failure seems to be that our test for the EGA
seems to poke into the keyboard routines on this machine. This problem
does not seem to occur on the AT&T 6300+. The best advice would be to
contact AT&T about a BIOS upgrade since many programs that test for the
presence of the EGA may encounter this type of difficulty. However, the
following patch can be used to bypass the EGA test. Later versions of
DESQview will probably code around the problem and will not require the
patch. AT&T users interested in upgrading their ROM can call AT&T
support at 800-922-0354.

To create the patched DESQview file, you will need a copy of the DOS
utility DEBUG.COM. This can be found on your DOS Supplemental directory.

The patch:

... First, copy your DV.EXE file to a backup file. In case the patch
doesn't work, you can restore the original and you will be no worse off.

C:\dv>COPY DV.EXE DVBACK.EXE {ENTER}

... Next, rename your DV.EXE to DV.XXX so that it may be patched. This is
necessary so that DEBUG will load the file properly.

C:\dv>REN DV.EXE DV.XXX {ENTER}

... Next enter DEBUG using the DV.XXX parameter.

C:\dv>DEBUG DV.XXX {ENTER}

... Debug will load the program and present you with a hyphen as a prompt.
To this prompt, type an "R" and hit the Enter key. You will be presented
with a display similar to the one shown below. It is not necessary that
you understand this (aren't you glad?).

-R {ENTER}
AX=0000 BX=0001 CX=BBA0 DX=0000 SP=FFEE BP=0000 SI=0000 DI=0000
DS=???? ES=1F87 SS=1F87 CS=1F87 IP=0100 NV UP DI PL NZ NA PO NC
1F87:0100 4D DEC BP

... In the space following the "DS=" in your display, which in the example
above contains "????" you will see four alpha-numeric characters. Take
note of these characters and to the hyphen prompt, type "H" followed by a
space, then the number following the "DS=", then another space and "1000"
as illustrated below. Follow this by hitting the Enter key and you will
see two sets of characters shown below as "XXXX" and "YYYY". Only the
"XXXX" will be used for the patch.

-H ???? 1000 {ENTER}
XXXX YYYY
... Now to the hyphen prompt type "S", the four characters shown in "XXXX"
above and ":0 FFF0 26 c6 06 74 00 18" as shown below and hit the Enter key.

-SXXXX:0 fff0 26 c6 06 74 00 18 {ENTER}
????:????

... Debug should return two sets of four characters each separated by a
colon. This is shown above as "????:????". If DEBUG returns to the hyphen
prompt without returning this set of characters, this patch will not work
on your copy of DESQview and you should type "Q" and hit Enter to quit
DEBUG. If it did return the characters, continue:

To the hyphen prompt, type "E" followed by the characters shown above as
"????:????". Then hit the Enter key. DEBUG will respond with a line
ending with "26" and an underline cursor. To this prompt, type "EB" and
then press the space bar. Debug will respond with a line ending in "C6"
and again wait for input with an underline cursor. Type in 04 and hit the
Enter key.

-E????:????
????:???? 26. EB {hit spacebar}
????:???? C6. 04 {ENTER}

... Debug will return the hyphen prompt. To this prompt, type "W" and hit
the Enter key. Your disk will light up and Debug will indicate that it is
writing a given number of bytes.

-W {ENTER}
Writing ????? bytes

... At this point, the patch is complete and the file has been written to
disk. Return to DOS by typing "Q" and hitting return.

-Q {ENTER}
C:\DV>REN DV.XXX DV.EXE

... Finally, rename DV.XXX to DV.EXE (shown above) and then enter DESQview.
If your patch has been successful, DESQview should now run properly.

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