DUNNO by Stefan Posthuma
It's a dirty job but someone's gotta do it!
We care a lot
About diseases, fires, floods and killer bees
About the smack, the whack, the crack that hits the STREETS!
"Hey!....Kill that noise!!!"
My dad's head looks a little malformed by the voilent vibrations
of the air in my little room. His eyes look really mean and I
sense negative vibrations towards the new piece of vinyl I've
just obtained at Elpee.
"My god Stefan, the entire neighbourhood can hear this noise!"
"Try to control yourself."
The door closes and I remove the newest record from Faith No More
from my record player, and subsitute it by something more moody
by Climie Fisher.
Of course you must have heard of We Care A Lot by Faith no More.
This is THE Greatest Collection of Sound since 'Fight for your
right' by the Beasty Boys. Even so great that I bought a single.
Normally I only buy maxisingles and very seldom an album, but
never singles. But the guy at Elpee told me that the Maxi had not
been released in Holland (yet...) and so I bought the single.
Sigh...I just returned from my visit to Evelien, and my mind is
still with that fantastic and inspiring girl. She really has
'Angel Eyes' (yes, I'm in a musical mood) and Heaven really is
missing an Angel now. Also, if anyone should ask, we are mated
and I had the time of my life.
I feel like writing an article, but I don't know what to write
about. Just a sec, Climie Fisher has ended, so I replace it by
something even more moody, the album 'Images' by Michael Garri-
son. Real dreamy synthesiser music. So I went from Faith No More
through Climie Fisher to Michael Garrison. I'm dropping from
wildy aggresive (in a non-voilent way, just a little head-
banging) to dreamy serenity. This might result in me sleeping
peacefully behind my faithful ST, dreaming of a certain girl...
I am just boring you with stuff you are not interested in at all.
This is an ST magazine and you like to read about interesting ST-
stuff. So let's start anew and create an article instead of a
pathetic description of my romantic feelings towards a divine
I think I'm gonna hit the stereo again an play some Public Enemy
to get myself going and create something! The result will be on
the next page. Hold on.....
By the way, you should read the book 'Exciting foreplays with an
Inflatable Phallus'.....(You Dutch and seen the 'Tros Actua'
issue on TV?! Zum Kotzen!)
CREATING SPECIAL SCROLL EFFECTS
After watching the Best Demo Ever on the ST - TEX's B.I.G. demo -
it started thinking about the things they did. Especially the BIG
scroll fascinated me. Those giant letters just sliding smoothly
between a foreground and a background. Also, how does a crystal
scroll work? (A crystal scroll is a scroll in which a technique
is used with 'transparent' graphics. You can still see the
background through the letters of the scroll)
It crushed my mind for a few days, and suddenly, while playing
around with Degas Elite, it came to me. I screamed a little,
banged my head a little, kissed my ST a little and started
programming. One week later, the Small Demo was finished. It
isn't much of a demo, just a scrolling text and a Degas Piccy,
but while the demo is running, you can choose the scroll
technique to be used. The techniques are:
* Just plain scrolling, the letters cover the background entirely
* Scrolling between a foreground and a background
* Scrolling behind the picture
* 'Crystal' scrolling over the background
* 'Crystal' scrolling between a foreground and a background
With foreground and background you should imagine a picture with
a mountainside on the background and some pillars and small
mountains on the foreground. The text covers the mountainside,
but the text itself is covered by the pillars. This really looks
It all comes down to planes and colour palettes. When scrolling,
just one plane has to be scrolled. This means that the letters
can be pretty big, maybe even bigger than the letters from the
BIG demo because scrolling one plane doesn't take much time, but
I didn't try that (Michael from TEX told me that three-quarters
of the screen can be scrolled this way). To achieve the different
techniques, different colour palettes have to be used. Maybe you
don't know what a plane is. It will explain it briefly, but for a
real explanation, refer to some book one the subject (I don't
know exactly which book, so I can't mention any titles).
In low-resolution (we're talking about this resolution here), the
colours are determined by planes. To achieve sixteen different
colours, four planes have to be used. Planes should be seen as
bits, and with four bits, we can make 16 different combinations.
The bit pattern in the four planes forms a number and this number
is the number of the colour register to be used.
The screen is divided into groups of four words. (16 bits in a
word) Every word contains a different plane for 16 pixels on the
screen. So if the first bits of four words on the screen are set,
colour 15 is used for that pixel. If the second bits of those
words are all cleared, the pixel next to the previous one will
have colour number 0. So groups of 16 pixels will be represented
by groups of four words. Now consider this:
You have designed a colour palette with eight great colours.
These are in the first eight, that is. So the rightmost plane of
these colours are all set to zero. (Clever ones will say
'rightmost? shouldn't that be leftmost?' This is true, but for
some reason the bit patterns have to be read from right to left)
Now if you make the next eight colours the same colour, let's say
red, the only thing you have to do to make a pixel red it to set
the rightmost plane. This is to clue to it all, so make sure you
If you want to create a scrolling text, design a font in colour
number eight. This means that only the rightmost plane it set.
Now just scroll the fourth plane in your picture with a lot of
ROXL's. Let's say register A0 contains the adress of a plane on
the screen which is on the left of the screen, (this if you want
to make a plain left-to-right scroll over the entire screen) and
A1 contains the adress of the letter buffer. Now create code
looking like this:
do_scroll: move.w #37,d0 ; the letters are 37 pixels high
dos1: lsl.w 14(a1) ; scroll 1 pixel to the left
roxl.w 6(a1) ; the letters are 32 pixels wide
roxl.w 158(a0) ; scroll the screen
roxl.w 150(a0) ; steps of -8, scroll one plane
repeat this with steps of -8
adda.l #160,a0 ; 160 bytes: one screen line down
dbra d0,dos1 ; do the next screen line
rts ; end of routine
(this code comes straight from the source of the SMALL demo)
Now if you change the colour palette, let's say the last three
colours (13 14 15) are not red, but the same as their equivalents
in the first eight (5 6 7) and you design your picture carefully,
(using the first five colours for the background and colours 5, 6
and 7 for the foreground), the letters will scroll between the
foreground and the background. Just like that! I was thrilled the
first time I saw it, it is so simple!
Now crystal scrolling. This is just as simple as the technique
described above. Just design the last seven colours in a way that
they are a mixture between red and their equivalent of the first
eight. So if colour 7 is dark, colour 15 should be dark red and
if color six is light, colour 14 should be light red. Just
experiment with different colours until the desired result is
This is it. As you can see, it is very simple and does not
require any difficult raster-programming. In fact, the Small
Demo doesn't use any interrupts. It used standard calls to read
the keyboard and stuff. Of course TEX uses a horizontal raster in
the BIG scroll to achieve the many colours in the letters.
As said before a couple of times, the techniques described above
are really simple. But in order to create a really nice demo, you
should do more. It requires great music, rasters and things like
border-graphics. Also, I don't think anybody can create a demo
more stunning and breathtaking than the B.I.G. demo from TEX (I
believe the technique was also used in the first Psych-O-Screen
by the way).
Many greetings from Stefan.
Editorial remark: The SMALL demo can be seen at places where
Stefan roams. It is not available, as it will be a part of the
mega-fantastic "Synth Sample V", due out soon!
Special Message on the next page
A word from the Digital Insanity Advertising Agency
Tired of living? - Has your boss bought an Amiga and wants you to
program it? - Just feeling depressed? - Has your girlfriend left
you because she is in love with Don Johnson? - Has your
boyfriend left you because he fell in love with Danuta? - Wanna
find out what dyin' is all about? - Did your ST broke down? - Got
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Just found out that Samantha Fox already has a boyfriend?
In other words do you want to kill yourself????
Do it in an original way...go for a ride on the back of Richard
Karsmakers' bicycle. He'll ride like crazy, torturing your
behind, zig-zag past both stationary and driving cars, ignore
traffic lights, show-jump over traffic-hills and violate all
traffic laws in a few minutes. He'll make your last moments
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.