GFA BASIC TIPS & TRICKS by Richard Karsmakers
Some more GfA Basic Tips & Tricks this time. Hopefully, I won't
get that much questions anymore that can be traced back to Xbios-
, BIOS-and GEMDOS calls, because the answers to these can all be
found in an earlier issue of ST NEWS!
1) How can I build up a screen without people seeing it?
Afterwards, I want to send it to the visible screen in one time.
Using the Xbios function 5, you can make the people see a screen
on which you're not working. For example, if you are displaying
the screen on &H78000, you can work on &H70000 by entering the
The people will see &h78000 as screen, but you can now work on
&h70000. You can simply PRINT, FILL, etc., and all will be
directed to the &H70000 address. If you want to switch on the
screen visibly to &h70000, you should enter:
A value of '-1' means that the value stays as it was.
2) How do I load a program (using EXEC(3,...)) and keep it in
memory, ready to run?
I am afraid nobody knows how to do that. Even the STRIKE-a-LIGHT
people have had this problem, and they have not been able to
solve it. Sorry, I don't know. But I will get back to this once
someone has found it out!
3) How do I make my computer from 1 to .5 megabyte using GfA
This can be done by entering the following line:
This sets the Physical Top of RAM to &H80000. To change it back
to &H100000, you should use:
Spoke &H42F,16 !(16=&H10)
Watch out! The new memory size will continue to be, also after
you press reset! RAM size has to be redefined or the system
turned off/on to recover.
4) I have problems using the Escape codes. When I use
things go wrong. What must I do?
Everything is simple. Just replace Chr$(27),"Y" by Chr$(27);"Y".
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 Any contact and/or payment information, as well as deadlines/release dates of any kind should be regarded as outdated.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.