VGA2CGA (c) Copr. 1989 Lawrence Gozum & Marvin Gozum
This product is distributed AS IS. The authors specifically disclaim all
warranties ,expressed or implied, including ,but not limited to, implied
warranties of merchantability and fitness for a particular purpose with
respect to defects in the diskette and documentation, and program license
granted herein, in particular, and without limiting operation of the
program license with respect to any particular application use or
purpose. In no event shall the authors be liable for any loss of profit
or any other commercial damage including but not limited to special,
incidental, consequential or other damages.
You may use this program on a TRIAL BASIS only; this means that you may
freely evaluate the usefulness of this program for 10 DAY TRIAL PERIOD.
Should you find this program useful, you must register it (see last
section of this manual). You will then be provided with the latest
releases of applications that will run on your system.
You may freely distribute copies of this program in its UNMODIFIED state
provided you do not include it in other software packages, with the
exception of distributing it as part of a bundle of Public Domain or
shareware programs on a single diskette. You may not charge more that
$3.50 for copying and/or distributing this program in the absence of
recognized Users Group guidelines (e.g., Association of Shareware
Professionals or New York Amateur Computer Club)
WHAT IS VGA2CGA ?
VGA2CGA is a utility that converts/views colored GIF pictures (256 colors
and less) and any of the following listed below to  error-distributed,
4-color dithered CGA or 16-Color CGA pictures, with a special unsupported
mode; CGA users can convert/view up to 405 colors (from 16 color dither
patterns). VGA2CGA saves to GIF or .CGX (for the unsupported mode); you
can use VGA2CGA as a CGA viewer for use in batch (.BAT) files.
1) ANY colored GIF picture (32 colors and up recommended), with any
size (up to 2048 x 2048 x 256).
2) ANY VIEWABLE VGA/MCGA 320x200x256 picture captured with VGACAP;
3) VGACAD pictures;
4) 16-color pictures converted to 320x200x256 with EGA2VGA.
VGA2CGA uses a unique error-distribution algorithm; it uses a Floyd-
Steinberg matrix with Stucki filter values (8,4,2,2). Users can
individually adjust the color and contrast levels and dither density.
CGA2VGA supports a "quarter-resolution" mode by direct manipulation of
CGA registers. 16 colors can be displayed at any time. The effective
pixel resolution is 640x200x16 with 405 color dither combinations.
SEE THOSE 256 COLOR GIF PICTURES ON CGA !
WHAT IS VGACAP ?
VGACAP is a terminate-stay-resident (TSR) utility that captures 256 color
palettes and screens in VGA/MCGA 320x200x256 color mode. VGACAP will
capture and "Bsave" the pictures of commercial and other Shareware
VGA2CGA requires, at the minimum, a 100% IBM Hardware Compatible CGA
card. Hercules users with HGCIBM may find that the program works on
their system, BUT ONLY WITH OPTION (1) AT THE MAIN MENU.
SVGA and EEGA card users must set CGA hardware emulation to see the
unsupported 160x100x16 or 80x100x"405" mode (e.g, "SETMODE IBMCGA" on
STB VGA cards).
About 512KB of memory is required, although it uses about 2/3 of that.
You MUST have a VGA or MCGA adaptor (at least BIOS compatible) present
and an analog monitor to use VGACAP. VGACAP uses less than 2K of RAM.
HOW TO USE VGACAP
Run VGACAP before entering your painting/CAD or digitized picture
program and your current screen and palette will be saved in your default
drive and directory in the standard Bsave format for all BASIC programs.
The first time you run the program it will save your screen and palette
to SCREEN00.BLD and SCREEN00.PLT respectively. If there is an existing
SCREENxx.BLD or SCREENxx.PLT file, then it will increment to the next
higher number. You can use your favorite memory managers to remove this
TSR or reboot to release it from memory.
Note: When in DOS or using a picture viewer (e.g., PICEM, VPIC,
VGAGIF) or application which requires a keypress to continue, it is
necessary to hit another key after hitting the 'HOTKEY'.
LOADING PICTURES INTO VGA2CGA
Two formats are accepted by VGA2CGA: GIF and BLD/PLT files; At the start
of the program, you will be prompted to select [G]IF or [B]LD files to to
selected or [Q]uit to exit.
All pictures are interpolated to a 320x200 size. As such, SuperVGA GIF
files (e.g., 640x480x256, 800x600x256 and 1024x768x256) are interpolated
to 320x200x256; SQZGIF is recommended for LARGE GIF pictures to retain
more color information and better color rendition.
16-color EGA/EEGA/VGA pictures will also be interpolated; use EGA2VGA to
process such pictures before loading into VGA2CGA.
You can select any filename by moving a highlighted bar (with the arrow
keys) and pressing the
a different PATH, while
sure it has a corresponding *.PLT file or a error message will result.
PATHs MUST end with a backslash character "\" or your specified PATH will
be rejected (an error beep will result). The following are legal PATH
Every captured picture, VGACAD picture, converted EGA2VGA or SQZGIF or
MAC2GIF picture will have two files:screen and palette. The extension
.BLD stands for BLoaD and .PLT for PaLetTe.
THE MAIN MENU
After successful loading of your picture you will see these options:
(1) Red-Grn-Yel Plane Dithering 320 x 200 x 4 (IBM-STD w/ GIF save)
(2) EGA Low Contrast Emulation 160 x 100 x 16 (NON-STD w/ CGX save)
(3) EGA Med Contrast Emulation 160 x 100 x 16 (NON-STD w/ CGX save)
(4) EGA Hi Contrast Emulation 160 x 100 x 16 (NON-STD w/ CGX save)
(5) EGA Monochrome Emulation 160 x 100 x 16 (NON-STD w/ CGX save)
(6) HI Color Averaged Dithering 80 x 100 x 405 (NON-STD w/ CGX save)
(7) LO Color Averaged Dithering 80 x 100 x 405 (NON-STD w/ CGX save)
(8) Grey Averaged Dithering 80 x 100 x 13 (NON-STD w/ CGX save)
Select the letter or the number to initiate that function or option.
VIEWING & SAVING
Whenever you select a viewing mode you will have the option change the
path and file names for saving.
Pathname : C:\GIF\
Filename : NONAME.GIF
While viewing the picture in CGA 320x200x4 mode you can change the
palette to alter the tone of the picture by pressing numbers 0-9.
With unsupproted modes 2 to 8, only saves to a CGX file are allowed since
it is a weird text screen format; the .CGX extension is provided to avoid
confusion with your other .BIN files. To use VGA2CGA as a viewer type
"VGA2CGA [picname]" without the extension.
To get the BEST color dithering or color matching, interactively adjust
the color levels, contrast levels and dither density levels.
When you select (F)ine Tuning, you can adjust the global amounts of Red,
Green and Blue in you picture. At default it is 100%; this can be
increased up to 200% The CGA 320x200x4 color mode uses only red and
Green; Blue is disregarded.
While "fine tuning", you can adjust the contrast levels for each of the
RGB planes; this has no effect on color-averaging and is limited to the
red-green-yellow dithering 320x200x4 mode. Increasing the contrast will
increase the amount of "black" in the picture by making a sharp cutoff
(i.e., no color will be plotted).
Dither Density is how closely packed neighboring pixel will be; at
default this is set to 1 - the highest density possible. If you want to
"spread the dots" you can increase this level up to 200.
BONUS: Registered users of VGACAD v1.4-1.5, VGA2EGA v1-2, SQZGIF
v1.0-v1.3, GIFDOT v1.0-1.3, MAC2GIF v1-2 and/or EGA2VGA v1-3
and/or GIFPUB v1.0-v1.4 are registered. Copy your REGISTER.OVL
file into the directory of VGA2CGA and it will operate as a
registered version. IF YOU HAVE NOT REGISTERED ANY OF THESE
PROGRAMS, DO SO NOW; when VGACAD v1.60 is released, all new
releases will require REGISTER.V16 to operate as a non-shareware
For 19.95 (outside of U.S.A. add USD $15.00) you will be entitled to the
latest update of VGA2CGA and REGISTER.V16 file (when released). The
following programs listed below are provided (latest copy or update) to
registered users. As much as possible, we are changing all utilities to
work with ANY video card; programs that, at present, work with ANY video
card are: GIFPUB, GIFDOT, EGA2VGA, MAC2GIF and SQZGIF. We intend to
release as many utilities to with device-independent capabilities. If you
upgrade to EGA or VGA, please inform us as soon as possible so that we
may send you EGA-dependent and VGA-dependent releases too.
* Device-independent utilities
GIFPUB - converts 256 color GIFs to B&W images of varying sizes for
desktop publishing/printing as .PCX (ZSoft format for Ventura Desk Top
Publisher, First Publisher, Publisher's Paintbrush, PC Paintbrush+) or
rename files to .PCC for importing in Aldus Pagemaker.
GIFDOT - converts 256 color GIFs to B&W images of varying sizes for
printing on IBM and Epson compatible printers (separate drivers).
Several print sizes with perfect aspect ratios. Variable Brightness and
Contrast Stretching. Single or Double pass printing. Histogram Analysis
SQZGIF - converts LARGE GIF pictures (up to 2048x2048x256) to 320x200x256
using interpolation and "color averaging" techniques to blend/smooth
"jaggies" inherent in reducing LARGE GIFS while retaining a maximum of
MAC2GIF - converts .MAC ("readmac") pictures to 5-16 grey shades or color
and saves results as .GIF or BLD/PLT file, and other formats; graphics
are viewable in VGA, MCGA or EGA - no video card is required for direct
Black & White conversion to GIF.
EGA2VGA (v3.0) - converts GIFs (16 colors and below) or ANY VIEWABLE 2-16
color EGA/EEGA picture to 320x200x256; creates 256 new colors; outputs
directly to GIFPUB, GIFDOT, VGACAD, VGA2CGA or VGA2EGA.
* Device-dependent utilities/applications
VGA2EGA - Conversion program for displaying 256 color pictures on
EGA-bound systems. Features extensive control of RGBCMY color, contrast,
dithering levels. Variable Sizing. Extended EGA support. Saves to GIF.
Optional PCX save to 4 RGBI planes for Desktop Color Separation.
VGACAD - extensive paint/image processing program for VGA/MCGA users;
v1.50 features extensive paintingcapabilities, an integrated GIF
interface, Airbrushes, color and grey image processing functions
(smoothing, noise removal, shading, contrast stertching, edge detection,
high frequency-boosting, ... more), Bezier/spline curves, multi-featured
Cut&Paste, variable sizing, multi-directiona 256-color gradient fills,
256 color 16x16 pattern fills, and a LOT of other 256-color capabilities.
Whats next ?
SYNPCX is utility to convert dithered, monochrome .PCX (Zsoft) files to
smooth grey shades. This utility is primarily designed to convert
scanned (e.g., Logitech & DFI hand scanners) Black & White images, saved
to a .PCX file, for use and image processing with VGACAD, redithering
with GIFPUB, printing with GIFDOT, or EGA conversion with VGA2EGA.
SYNPCX will be graphics device independent (No Video Required).
We are also, developing VGASHW (a 256-color presentation system), VGACBT
(the PROGRAMMABLE Computer-Based Training counterpart of VGASHW) AND
MANNEQUIN (what "Weird Science" tried to do in the movie it will do on
the computer screen with potential applications for Advertising and
Fashion Design, aside from creating your own artistic nudes).
If you support maverick authors like us, we will continue to develop
innovative products like nothing seen commercially - otherwise they will,
as many (sigh!) good Shareware programs, simply "DIE" from lack of
support ! Compare the cost/benefit ratio of any of our products with
commercial products; we want to continue supporting and developing these
products. Please support the User-Supported (Shareware) concept; you,
and you alone, determine whether it will be worthwhile to continue
To register, send in the registration form and check payable to
Dr. Marvin Gozum
2 Independence Place Apt. 303-2
6th & Locust Street
Philadelphia, PA 19106
NEW! 3.5" disk users: We are now supporting this format.
If you want your updates in this format, add $10.00.
Graphics Interchange Format and GIF are trademarks (tm)
of CompuServe Inc. an H&R Block Company.