GRAPRT - Dr. Laurence D. Preble (70275,134)

     Graprt is a machine language program which can rapidly display digitized 
pictures on the screen of the Tandy 200.  In addition, Graprt can do a fast, 
machine language screen print to any Epson compatible printer.  The screen 
print subroutine may be accessed independently.  Either the display routine or 
the screen print routine may be called from your BASIC programs.

     Digitized picutres must be coded in the same format that Compu-Serve uses 
for Vidtex Weather maps (Run Length Encoded files).  In fact, Graprt is an 
excellent tool to use to display Vidtex Weather Maps.  Simply use MAPPER.MOD in
Telcom section 2 to download a weather map.  Then use Graprt to display the 
map.  I am also submitting some digitized art work for your perusal.  (See 
DOCTOR.RLE, ILENE.RLE, DIAGRM.RLE AND SUMNIT.RLE in this section for examples.)


INSTRUCTIONS:

     This program is encoded into a BASIC program (thanks to Richard Haw's 
BASIC encoding method) which then pokes the machine language code into memory 
at any address you specify.  Proper relocation will be obtained automatically. 
Just download the BASIC program and RUN it to get the ML code into memory.

Start up.

     When Graprt is first activated, it will look for a Hi-res graphics file 
called PIX.DO.  If there is no file in memory by that name, then Graprt will 
ask you for a filename to plot.  In other words, PIX.DO is the default name 
GRAPRT expects.

Commands:

     CTRL - P	Graphic Screen Print

     To do a screen print (Epson Compatible only), press CTRL - P.  (Hold the 
control key down and press P).  This activates the screen dump subroutine which
will print the graphics on the screen as fast as your printer can accept them.

     CTRL - I	Invert

     You can do a pixel inversion by pressing CTRL - I.  That will make the 
black areas white and make the white areas black.

     Cursor

     Some pictures are too big to fit on the TANDY 200 screen all at once.  You
can move the picture up or down and right or left by pressing the appropriate 
cursor keys.  By the way, if you do a screen dump to the printer on the top 
portion of a picture, you can then display the bottom half of the picture and 
do another dump.  The printed picture will be continuous rather than in two 
pieces.

     Exit - (Enter or Space)

     To exit to the Tandy 200 Main Menu, just press ENTER after displaying the 
picture.  To Exit back to a BASIC program which will then continue execution, 
press the SPACE bar.

     Alternate entry point - Start + 3

     You may call the Screen Print subroutine independently from BASIC.  The 
entry point is the start of GRAPRT.CO + 3.  So, for example, if you have 
located Graprt between 60122 and 61102, you would call the screen print utility
at 60125.

     Downloading picture (.RLE) files

     Read the files off compuserve like you would any text file.  The charaters
will appear meaninless, however, until decoded by this program after you have 
signed off Compu-Serve.