Dec 232017
 
Use DOS 4.01's GRAPHICS.COM on DOS 3.30 machines to get EGA & VGA screen dumps. Text file explains how to PATCH 4.01's GRAPHICS.COM using DEBUG.
File DOSGRAPH.ZIP from The Programmer’s Corner in
Category Printer Utilities
Use DOS 4.01’s GRAPHICS.COM on DOS 3.30 machines to get EGA & VGA screen dumps. Text file explains how to PATCH 4.01’s GRAPHICS.COM using DEBUG.
File Name File Size Zip Size Zip Type
GRAPHICS.TXT 2219 1021 deflated

Download File DOSGRAPH.ZIP Here

Contents of the GRAPHICS.TXT file


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
******************************************************************


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

*********************************************************************

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

*************************************************************************

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 !!


************* eof ****************



 December 23, 2017  Add comments

Leave a Reply