~p 10 0 0
~w 5 3 75 23

~gr 15 lrub
~w 6 4 74 22
Use the cursor keys to scroll up and down. Esc when ready.
~w 6 7 74 22
~w1 0
Setting colour masks for EGA/VGA dumps


First we will discuss the use of a colour mask on a black
and white printer. After that, extending the principle to
colour printers will be easy.

There are four 16-colour EGA/VGA screen types, having a
resolution of 320*200, 640*200, 640*350 and 640*480
pixels. On a 9-pin dot matrix printer it would not be
practical to try to print all these colours as hash
patterns, so FASTDUMP does not. Instead it lets you
choose which colours to print, and which not to.
For instance, in many scientific applications, you will
have a graph with a black background, and you want to
print everything that is not black. Or in SlideWrite, you
want to print everything that is not black or blue
(because those are the background colours).


You select which colours to print and which not to by
executing
FASTDUMP /EB................
where you substitute each of the 16 '.' with a

1    to start printing the corresponding colour
0    to stop printing it
?    to leave its status unchanged

Omitting trailing '.' is the same as typing '?' for them.

The 16 colours are, in the correct order:

15             white            7       light grey
14            yellow            6            brown
13     bright purple            5           purple
12        bright red            4              red
11              cyan            3             cyan
10      bright green            2            green
9        bright blue            1             blue
8          dark grey            0            black


The default setting is /EB1111111111111110, so only black
will not be printed. This default is loaded when you
first start the programme, and also each time you execute
FASTDUMP /C-
to stop colour printer support.

The settings you would use for the examples mentioned
earlier would be:

for the scientific application
FASTDUMP /EB1111111111111110 (same as default)
for SlideWrite
FASTDUMP /EB1111111111111100
under Windows
FASTDUMP /EB0111111111111111
or the default and inverted printing:
FASTDUMP /EB /I+

If you have used
FASTDUMP /C+
or
FASTDUMP /Cs
to indicate you are using or want to simulate a colour
printer you may also specify masks for the additional
printing colours red, yellow and blue. The syntax is the
same as for setting the black mask, except instead of /EB
you use /ER, /EY and /EU, respectively.

By default the EGA colours are dumped as follows on a
colour printer:

            print BRYU                    print BRYU

15          white 1000            7  light grey 1000
14         yellow 0010            6       brown 0010
13  bright purple 0101            5      purple 0101
12     bright red 0100            4         red 0100
11           cyan 0001            3        cyan 0001
10   bright green 0011            2       green 0011
9     bright blue 0001            1        blue 0001
8       dark grey 1000            0       black 0000

These default colour masks are active when you first load
FASTDUMP. Executing
FASTDUMP /C+
or
FASTDUMP /Cs
does not affect the masks for red, yellow and blue, but
does have /EB1000000110000000 as a side effect. This
means your settings of the masks for the RYU colours will
be preserved if you make a small excursion into black and
white territory.


Now that you know the principles of setting colour masks
using the FASTDEMO option should not prove too difficult.

The option displays a 640*350 16 colour EGA screen.
The top half of the display contains three test images:
a (somewhat) typical scientific graph (15 sinoids), a quilt
(used as an example of a thoroughly colourful image) and 16
colour boxes (containing the 16 standard EGA colours).

The bottom half of the screen is where you can make changes
to the colour masks. For each of the printable colours black,
red, yellow and blue there is a line containing a block for
each of the 16 EGA colours that will be printed in the colour
of that particular line. Of course, an EGA colour can be
printed in several printer colours to get composite colours.
You may modify the colour lines by going to the position you
want changed and pressing either the space bar or return key to
toggle the mask setting. The commandline and FASTPROC colour
mask values at the right of the screen will be modified to
reflect the changes you make.

Pressing the 'c' key toggles between full colour and B&W printer
support. Pressing the 's' key toggles simulated colours support
on a B&W printer.

Pressing the 'p' key creates a preview of a full colour or B&W
printer dump of the current screen on the screen. Normal colours
are restored when you hit ANYKEY.

Pressing the (shift)-PrtSc key creates dumps of the three test
images on the printer using the current colour support and mask
settings.

Pressing the ESC or F10 key returns you to the main menu. The mask
settings will be used if you print an EGA type screen in the
gallery of test images. If you have printed a colour image the
gallery dumps will also be in colour, otherwise they will be in
simulated colour.
~p
