Amiga Computing - Commodore Is Awesome

OTCHA. its me again, here to
update you on the wonderful
world of AMOS. Since our last
meeting so much has happened it's
hard to know where to start.
Probably the most important thing is
that a new version of AMOS is now
available, so get a copy from the AMOS
PD library (phone Sandra Sharkey on
0942 495 261 for more details. The
improved V1.2 has a vast number of
bug fixes. including those listed below.
LDIR
sof HARD
SC IN
VAL
PLOT
110
. INT
I SPRITE I BOB
op,
Amos It1_2 Bug Fixes
Now works properly
Returns the correct
value
Does not return
hidden screens
Works with negative
floating point
numbers
Works with large
floating point
expressions
Is now corrected
Both are now
tokenised (comput
erese for recognised)
AMAL OR Corrected
UNPACK W o r k s properly now
with portions of
.screens
,
4
1
1
1
1
6
1
1
i
4
AMOS V1.2 also includes a new file
selector and a number of new commands,
most important being the new
BOB and SPRITE flipping routines,
These commands allow you to reverse
the image of a bob both horizontally and
vertically and are completely compatible
with AMAL.
Available in your shops now are some
of the first products written with AMOS,
all of which are published by Database
Software. The software is Fun School 3
and consists of three separate packages
aimed at the under 5s. 5 to 7s and
over 7s. Each package uses very high
quality graphics (better than a lot of
games) and adheres closely to the
much publicised national curriculum. I
strongly recommend you go out and
buy all three, not only because they are
excellent products. but because I wrote
them! I might as well get my plug in now
'cos I didn't get a mention in the first
draft of the manuals.
Lastly in this little news file is some
4
'
1
information for comms users. Amiga
Connection BBS and Big Bang Burger
Bar BBS run a joint AMOS section
containing quite a few programs to
download. It also gives you access to
other AMOS users and because they
are both just a local phone call away
from me, I can be found routing around
on both at weekends. The two Sysops
are big AMOS fans and use it regularly,
so Hi to Paul Roffey and Paul Robert. I'll
upload some more stuff when I get back
from my holiday.
OK, lets do some work. AMAL — the
AMos Animation Language — is the
most advanced feature of AMOS. With
it you can move or animate SPRITEs.
BOBs, Rainbows and even whole
screens.
Its use is not limited to games, you
could do shop demos, fun demos or
produce animated titles for your videos.
We will start by loading a sprite file to
play with, so press Escape to go to
direct mode, insert your AMOS Data
Disk — the one with all of the games on
it — and type this
LOAD 'AMOS...DATA :MAGIC JORESIVIESPRITES ARK'
This will load the sprites from Magic
Forest into bank number one. You may
wonder why we are doing this in direct
mode. It's mainly because we need to
be able to see immediate results and it
is not too important to save the files on
to disk.
Now we need to set up a nice clean
screen display
FLASH OFF : CLS 0 I GET SPRITE pALETTE
DOUBLE WEER
Right now to display a bob and set up
its AMAL channel
BOB 1,50,50,1 : CHANNEL I TO BOB 1
We have our little geezer displayed
on the screen,but we want to move him.
The first thing to remember when
dealing with AMOS is that unless you
are converting a ST program never use
the STOS compatible MOVE X or
AMOS 3D - coming to an Amiga neat you
MOVE Y commands. They are
nowhere near as flexible as AMAL and
you will quite often end up with some
very tacky movement.
To move this funny little creature we
have to define an AMAL program.
AMAL is quite simple to use, a lot of
people have told me they found the
manual explanation quite daunting, so I
won't rush and we'll go through each
command step by step.
The first thing to remember is that
AMAL is a case dependant sublanguage
— more compterese for
saying that it can tell if you have typed
in capitals or lowercase letters. Any
commands that we enter into our AMAL
string will have at least one letter in
upper case and the rest in lowercase.
Of course this isn't quite true for all
AMAL commands, because a very few
require two uppercase letters but we
won't worry about those for the time
being.
To move an object we have to use a
command called Move (surprised
huh?), which uses three parameters.
The first is the number of pixels the
object should move in the X direction,
that is across the screen. The second
is the number of pixels we wish to
move up (or down) the screen, remembering
that both these parameters can
be positive or negative numbers for
backwards or forwards movement.
The very last parameter controls the
amount of steps that AMAL will take to
move your object in the X or Y direc-