Improving Picture Printouts

By Alasdair Davis

Originally published in EUG #54

I have just a quick query but I'm sure it's one you will have heard before. To prevent having to sit in front of my computer reading screenfuls of text, I print out everything using the One Pass Text Printing facility. What this doesn't do though is print out any diagrams or pictures. There are sometimes quite a few of these I would like to have a hard copy of - and I use a screen dump to dump them to my black and white dot matrix printer.

The query I have concerns colours. Probably due to the screen dump I am using, only pictures in Mode 0 and 4 print out perfectly. If I attempt to print out, e.g. the Chicken and Fox opening screen on EUG #52, the printout is rather 'bitty', i.e. like the screen itself if loaded into Mode 0.

I suspect that it is the number of colours that causes the problem as it only manifests when there are more than two colours on screen. VDU 19 commands don't have any effect, and obviously ruin the effect of dazzling graphic displays.

Is there anyway of converting colourful screens to monochrome?

Alasdair Davis, Dumbarton

Yes, there is. Obviously I can't guarantee to solve the problem as there are so many different screen dump utilities and printers that it's hard to know where to begin. However, it sounds like you may be able to get around the problem perfectly by loading the screen into Mode 0 and then restoring the original definition of Mode 1.

The code for doing this was published in EUG #19 and was originally submitted to EUG by Alan Richardson, New Zealand. You will need to *LOAD the code into memory, go into Mode 0, *LOAD the (Mode 1) picture you wish to dump (It will look as you say, 'bitty') then CALL the machine code twice to clean it up. Depending on where your screen dump utility stores its own code, you may have to *SAVE the new picture before using your screen dump with it. As you're using screen memory, this will require a short program.

You will then have a high-definition black and white Mode 0 image and should be able to get a hard copy of it without trouble. You will receive a free copy of EUG #19 with this issue and will note that the demonstration picture on it is one of Kylie Minogue (digitised by Simon Pilley).

Dave E, EUG #54