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Precision Software Appli…tions Silver Collection 1
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Precision Software Applications Silver Collection Volume One (PSM) (1993).iso
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tutor
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typteach.exe
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BWVID.DOC
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1986-03-22
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6KB
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82 lines
The following is an Interrupt/Stay resident program that intercepts all
BIOS video calls involving color and maps them to black and white calls.
It will eliminate many of the fuzzy screens that arise from having
a BW monitor hooked up to a color graphics board.
THIS PROGRAM IS ONLY USEFUL IF YOU HAVE A BLACK AND WHITE HIGH RESOLUTION
MONITOR CONNECTED TO YOUR GRAPHICS CARD.
PROBLEMS THAT THIS ROUTINE SOLVES:
This program, when installed will remove all the fuzzy displays that
result when color display instructions are sent to BW monitor through
the BIOS system. The VAST MAJORITY of available code does go through
BIOS so this will catch most of those problems. This program works
by intercepting the following video calls and changing them as described.
SET MODE FUNCTION (INT 10H, AH=0)
If BIOS call is to set mode to 40x25 color then force mode to 40x25 BW
If BIOS call is to set mode to 80x25 color then force mode to 80x25 BW
If BIOS call is to set mode to 320x200 color then force mode to 320x200 BW
WRITE CHARACTER AND ATTRIBUTE (INT 10H, AH=9)
Intercepts BIOS calls to write attributes and characters and changes
the attributes. In the following, "Normal Video" is defined as White
(or Intense white) on black. "Reverse Video" is defined as black on white
(or Intense white). Attributes are modified as follows:
IF foreground and background are the same THEN
IF they are black or white THEN leave them alone
ELSE they are another color so force to white
ELSE
IF foreground is black OR background is white THEN force "Reverse V
ELSE force "Normal Video"
SCROLL PAGE UP (INT 10H, AH=6) or SCROLL PAGE DOWN (INT 10H, AH=7)
Intercepts BIOS calls to scroll up or down and changes the attribute
associated with the call as described immediately above for write charac
SET COLOR PALATTE (INT 10H, AH=11)
Intercepts BIOS graphic calls to set the palette and changes them such that
* Background is always black
* Foreground pallate always includes white (Color Id = 1)
WRITE DOT (INT 10H, AH=12) and WRITE TELETYPE (INT 10H, AH=14)
The "Write Dot" and "Write Teletype" intercept functions both map fore-
ground to white, regardless of the intended color.
PROBLEMS THAT THIS ROUTINE CREATES:
When information is transmitted to the view SOLELY through color
information, then that information is lost in this transformation.
(naturally!). So if, for example, a game has a color bar that switches
from green to red to signify danger, that information will be lost.
This is because generally all foreground colors are forced to white and
all background colors are forced to black. This is not so much a
problem created by this program as it is a problem with Black and White
monitors not conveying as much information as Color Monitors.
PROBLEMS THAT THIS ROUTINE DOES NOTHING ABOUT:
Any video calls that go straight to the hardware instead of going
through BIOS. It is unfortunately the case that some VERY sophisticated
programs that really have snazzy graphics do go to the hardware directly
because of the speed benefits.
After installing this program, all of the IBM Diagnostic tests look
reasonable.
When loaded this program uses 309 Decimal bytes of memory including the
Program Segment Prefix (It relocates itself down into the unused portion
of the Program Segment Prefix to save memory).
BWVID - Version 1.2, (C) Copyright 1985 by Scott W. Killen, All Rights Reserve
This program may not be used for commercial purposes without the
express written consent of Scott W. Killen.
Version 1.0 - 5/02/85
Version 1.1 - 8/20/85
Version 1.2 - 8/29/85
By:
Scott W. Killen
P.O Box 27012
Austin Texas 78755
CIS ID: 76703,734
512/836-1942
This program is GiveAware! The only payment I ask is your comments and
bug reports.