GFA BASIC TIPS & TRICKS by Richard Karsmakers
In this issue of ST NEWS, I again intend to solve some of the
frequently asked problems through this GfA Basic Tips & Tricks
1) I have this big problem. When I use the line
in high res to switch the screen memory to address Screenmem%,
I always find that the screen is cleared. Menu bars and
pictures disappear. What do I do wrong?
Answer: When you read in a book how to use Xbios function 5,
you'll notice that the last value (W:...) is used to switch the
screen resolution. If you do not want to change the resolution,
you should fill in '-1' there. If you don't do that on
monochrome, the screen will be cleared. So, the answer is:
Replace '2' by '-1' and everything will go nicely.
2) How do I load in a Degas (Elite) picture in GfA Basic, which
automatically sets the color palette?
Answer: Use the following small program....
This small program will load any picture into any resolution, so
take care that you load pictures fitting the resolution you're
in! It then sets the color palette using the Xbios 6 function
('Setpalette'). A Degas file is set up like this:
1- 2 Word representing the picture resolution
3-34 The color palette (16 words)
34-> The picture data
In the case of Degas Elite pictures, the color animation data is
also stored in the file, but only after the actual picture data.
Note that this routine only works with un-compressed pictures; it
works on all STs (any amount of memory).
3) How do I delete a file? Is it perhaps possible to supply me
with a small routine that does the work for me?
Answer: Type in the following program...
Print "File does not exist/already deleted?"
That's all for this time, folks!
The text of the articles is identical to the originals like they appeared in old ST NEWS issues. Please take into consideration that the author(s) was (were) a lot younger and less responsible back then. So bad jokes, bad English, youthful arrogance, insults, bravura, over-crediting and tastelessness should be taken with at least a grain of salt. Any contact and/or payment information, as well as deadlines/release dates of any kind should be regarded as outdated. Due to the fact that these pages are not actually contained in an Atari executable here, references to scroll texts, featured demo screens and hidden articles may also be irrelevant.