a E i - Commodore Is Awesome

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M any
larger industrial computers
offer a screen-dump facility. This
means that whatever is printed on the
screen can be reproduced exactly on
paper. Permanent copies may be
obtained of just about anything you
like including: Pie charts, histograms,
circuit diagrams, mechanical diagrams,
partial stock lists, program
modifications etc.
There are programs around for text
dumps, but most seem to be written in
Basic and need to ask the user
questions (like upper or lower case
text) before they will do a printout.
Enter then, the all singing, all
dancing. intelligent screen dump program.
This program will check automatically
whether upper or lower case
text is being displayed and print
accordingly. Reversed characters are
also recognised and dealt with by this
program (automatically). There is, of
course, one BUT...but it cannot print
the double quotes symbol. This is due
to an inherent function of the MPS-80 I
printer. When the printer prints an odd
number of double quotes, it starts to
print ASCII tokens for the printer
control codes used by this program.
The result is a totally disorganised
mess, which does not look much like
the original. For this reason the double
quotes symbol will be replaced by a
single quote every time it appears. This
is unfortunate but is the same method
used by the word processor package in
the Plus/4 itself.
While I am on the had points. I
should also mention that custom
characters cannot be dumped from the
text screen, though they can from the
graphics screen. Also, when obtaining
a graphics dump the last three rows of
PLUS/4 AND MPS 801 NI
Plus/4
Dumper
Non.' you can transfer what's on your screen to paper via
your printer and obtain a hard copy of everything you do.
By Mick Healey
pixels on the screen will not be
dumped. though this is usually unimportant.
Great care has been taken to make
this program 'invisible' to Basic and its
variables. Once loaded this program
can be considered as one of the computer's
functions. It lives and works
between locations $4000 and $467E.
Some of the routines used need to
change values stored in page zero. This
would then upset important vectors
stored in page zero and cause the
computer to crash. For this reason the
program will store page zero (in its
entirety) in a safe place, before any
damage is done. Page zero is then returned
at the end of the program. The
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end result of this is that the computer
has been made to produce a printout.
and will continue to do what it was
doing before, as if nothing had
happened (i.e.: this program is invisible).
The function keys have also been
re-assigned. This allows the text/
graphics dump to be used in direct
mode as well as program mode. Pressing
function key Fl will cause a text
dump to be produced. Function key
F4 gives a graphics dump. To include
these routines in a basic program then
call the following:
SYS 16384 for a text dump.
SYS 16645 for a graphics dump.
Bit number.
7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
This shows the pattern of bytes and bits as they
appear on the screen. (Two character spaces in
top left of screen represented.)
Figure 1.
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