GRAYGRAB v1.2
by Jeremy Stanley <stanleyj@cs.byu.edu>

Visit the GrayGrab homepage at:
     http://students.cs.byu.edu/~stanleyj/graygrab.htm


OVERVIEW

I have always been interested in getting a picture from the PC to the
calculator.  About a year ago, I wrote a series of programs to convert a
monochrome BMP file to a TI-82 or TI-85 picture.  (These programs are
rather unpolished and have not been released--if anyone would like to see
a version of GRAYGRAB that can output 85I files, let me know.)  With the
advent of ZShell and greyscale pictures, I sought a way to turn an image
from the computer into a greyscale picture for the calculator.  When I found
Rob Taylor's GRAY8 program, including a description of the format of these
pictures, I decided to write GRAYGRAB.  Here is the finished product.


ABSTRACT

GRAYGRAB allows you to grab a section of a PCX file and convert it to an
eight-greyscale TI-85 picture.


USAGE

The command line syntax of GRAYGRAB is as follows:

GRAYGRAB pcxfile [outfile[.85S] [string_name]]

All but the first parameter (the PCX file to be read) are optional.  If
the outfile parameter is not specified, the name of the input file
(but with the extension 85S) is used.  You may also specify the name of the
string as it will appear on the calculator--if this parameter is omitted,
the name of the output file is used.

I use the program "picview" (Graypic Vwr by EL&FF v2.1) to view the pictures
on the TI-85.  Any other viewer which uses Rob Taylor's picture format should
work fine.

When GRAYGRAB is started, you will see your PCX file centered on the screen.
A window in the center of the screen illustrates the TI-85's display.  You
may move and scale the picture to fit the portion you desire into this
window.

The keys are as follows:

Arrows - move picture
PgUp - Zoom in
PgDn - Zoom out
Home - restore picture to original scale and position
5 (on keypad) - center picture without adjusting scale
B - toggle background black/white
Enter - convert captured portion to greyscale and save 85S file
Esc - Cancel

Hold the Alt key while pressing the arrows for fine movement.


NOTES

To compensate for the TI-85's aspect ratio, you may want to scale pictures
to 84% of their original height before feeding them to GRAYGRAB.

This version of GRAYGRAB supports only 256-color PCX files.

The maximum uncompressed size of the PCX file is 64K.

Due to variations in the PCX file format, some pictures may not be displayed
properly.  In a future version of GRAYGRAB, I plan to include support for
BMP and/or GIF files.

Report any bugs or comments to me at stanleyj@cs.byu.edu.


REVISION HISTORY

v1.20  12/15/96  Improved command-line processing:
              -  GrayGrab now assumes PCX for the extension of the input
                 file if none is given
              -  The output file is always created in the current directory
                 unless specified otherwise on the command line
                 (Previous versions may have created it in the directory
                 of the input file if the output file was not specified.)
              -  The name of the output file now defaults to the name of
                 the input file instead of "GrayPic" (Of course, the
                 extension 85S is used in place of PCX.)
v1.10  12/14/96  Fixed bug that would cause the system to hang after using 
                 ESC to abort
              -  Added feature: Press 5 to center image 
              -  Added feature: Press B to toggle background color
v1.01  10/03/96  Minor revision to GRAYGRAB.TXT
v1.00   9/28/96  Original Release


TECHNICAL INFORMATION

Platform: MS-DOS
Minimum CPU requirement: 80386
Minimum video requirement: VGA

GRAYGRAB was compiled using Borland Turbo C++ v3.0, using my own graphics
library.  If you would like to see the source code of GRAYGRAB, e-mail me.


SPECIAL THANKS TO

- Texas Instruments
- The ZShell development team
- The ticalc.org team


EOF
