ROM STANDS YOUR TEXT ON ITS END
I HAVE been looking for a handy way of copying graphics from
the screen for some time.
As a teacher, the possibilities of children making a hard copy
of their work has always appealed to me.
True, I could always load a screen dump program into the computer
beforehand. But that did not give me the flexibility I was looking
for.
What I wanted was a simple, and fast, way of telling the computer
to send the information on the screen to the printer.
Just as I was pondering further on the problem, I found an advertisement
in this magazine that seemed to fit the bill. It also said that
it would magnify the dumped hard copy, too. Needless to say, a
cheque went in the post the next day.
After two weeks, a small envelope came winging its way into
my classroom.
On opening it I was rather surprised to find another, much smaller,
envelope. On opening that, I found a well-wrapped and protected
ROM chip.
On the front of the small envelope was a typed label telling
me how to get further instructions, once I had fitted the ROM.
After the usual 10 minutes to fit, the ROM was ready to be utilised.
*H.G. was the command I was told to use, utilising the
*HELP facility. This means that you would need a series
1.0, or later, operating system.
The instructions were, in turn, made into a hard copy by entering
Ctrl B before using the *H.G. facility.
The resulting instructions, delivered in a novel and effective
way, were on the whole quite clear.
The information section tells of the effects you can accomplish
using the ROM.
It will enable you to print upright or sideways — the latter
I have found useful for larger images — in single, double, triple,
or quadruple size.
It will also select a portion of the screen, if desired.
BBC modes 0, 1, 2, 3, 4 or 5 can be used. Any printer mode can
be used for Epson, Seikosha, CTI, NEC and others.
The syntax section, was not, at first, as clear as it could
have been for someone, like myself, who is used to Wordwise.
I was confronted with the following syntax:
*GDUMP pc sc st mg bg xl yb xr yt
I admit I was told to follow the command *GDUMP with
up to nine numeric arguments. But I nevertheless continued my
*W. habit of putting numbers after what I thought to be
command letters.
After three attempts it struck me quite by chance to try just
the numbers.
I think, for the slow learners like me, it would have been simpler
to have used the term WHERE. That is, where the letters stand
for a series of up to nine spaced numeric arguments.
The numeric arguments themselves are very easy to use:
pc stands for PRINTERCODE. Examples are given, for the
different printers, and your attention is drawn to the Escape
* codes in the printer handbook. Default setting is 0. For example,
Epson MX, and others, use 0 or 1 (where l=Double density).
sc stands for SCALE. The range is 1 to 4. The value 3
is not strictly triple size, but rather a useful 1.5 x horizontal
with a 2 x vertical scale.
Value 4, in conjunction with st, gives 3 x horizontal and 4
x vertical scale. Default setting is 2 x scale (H. & V.).
st stands for STYLE. 0 = upright or 1 = sideways print.
You have to add 4 to these for four-colour shading, or 8 for eight-colour
shading.
mg stands for MARGIN. This shifts the hardcopy print
to the right where mg = normal character spaces.
bg stands for BACKGROUND. This sets the GCOL number of
the background, normally 0 or 128. All other colours will print,
and changing the bg will alter the allocation of shadings to colours.
WINDOW x xl yb xr yt. These stand for the four sets of
graphics co-ordinates, as in VDU24, enabling you to pick a specific
part of the screen to be copied.
Default setting - all four zero (or omitted) treated as the
whole screen.
There then follows a series of notes, among which is advice
on halting the printing. Escape held down will not leave the printer
hung-up as the Break key will do.
The combination of screen mode 0 and scale = 1 can cause loss
of thin lines. Upright printing, in dual density, will cure this.
Styles 4 and 8 will not work with scales 1 and 2, presumably
because the colour-shading dumps need a scale * density high enough
to give full resolution.
Window size should be limited for the Seikosha (<479 dots
per line) and the NEC (<639 dots per line).
On the whole, I have already found this ROM to be dependable
and very useful and on present performance and versatility, this
Screen Dump has proven to be well worth the £15 quoted at
present.
For those of you wishing to use the results of the ROM, all
the screen dumps in this issue were done using it.
John Rivers
