SUMMARY: A way to use DOS 4.01's GRAPHICS.COM is DOS 3.3 machines
to obtain EGA & VGA screen dumps.
22 Jan 1991
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Versions of MS-DOS before 4.xx do not support EGA & VGA Screen dumps
with DOS's Graphics.com

Versions of Graphics.com in MS-DOS 4.01 do, but cannot be run on a machine
with MS-DOS 3.xx, as they detect the DOS version and will not load into
those machines.

HOWEVER: If the DOS version detection is "PATCHED OUT", it would seem
that a DOS 4.01 Graphics.com will run correctly in a DOS 3.3 machine.

Other Machines (Dos versions) may also work with the modified GRAPHICS.COM,
but I have only tried MS-DOS 3.30

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Here is a way to patch GRAPHICS.COM:

Assuming GRAPHICS.COM MS-DOS Ver 4.01 date 10-6-88 length 16,693

{using DEBUG}

DEBUG GRAPHICS.COM ; Run DEBUG on GRAPHICS.COM

E1764 ; Edit offset 1764

{ensure that 1764=04 & 1765=00} ; (check that it's the right version !!!)
{then edit 1766=75 to 90 (NOP)} ; ( THE PATCH : NOP out the jump if not)
{ edit 1767=03 to 90 (NOP)} ; ( DOS 4.0x )

W ; write the file back
Q ; quit DEBUG

Note: If you don't understand this... don't attempt it !!!!

Ensure that GRAPHICS.PRO is also present with GRAPHICS.COM

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This works for me, and the GRAPHIC DUMPS are a lot faster than many of the
Public Domain & Shareware programs currently around.

BTW: I would point out that I bought DOS 4.01 to upgrade from 3.30, but
found that I needed to stay with 3.30 for other software reasons.
Seeing that 4.01's GRAPHICS.COM supported EGA & VGA led to this
course of action.

It works for me ...... I hope it works as well for you.

Dos 4.01 Graphics.com is MUCH more powerful than previous versions, supporting
most printers with a user configurable GRAPHICS.PRO (profile) data file.

In order to make full use of its options & power, you need the DOCUMENTATION !!


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