Gangsters is an arcade
type game for 1 or 2 players. Each player starts with three men and an
extra man is awarded for a score reaching 2500. There are 9 levels of
increasing difficulty to choose from initially with each level
successfully completed leading automatically to the next until the
highest level is reached.
Player 1 controls a
blue gangster and Player 2 a green gangster and play commences at the
top left floor of the building. Remaining men are shown above the
building in the centre with scores at either side indicated by an
arrow. The level(s) being currently played or reached are shown below
the building at either side with the time in the middle. The object is
to reach the exit door at the bottom right of the building after
searching for and collecting bottles of bootleg. The whole floor of
the building must be covered within the time limit and 50 points are
scored for each bottle collected. Bonus points are awarded for any
time left depending on the level.
To hamper your progress
a rival gang are sending their own men in at the bottom exit to stop
you taking the liquor. If one of them comes across a bottle he
collects it and prevents you from colouring the floor and collecting
any more bottles yourself. In addition if, whilst in this temporary
state, an enemy gangster runs over any floor area you have already
searched, he will turn it back to its original colour. It is essential
that you track him down and shoot him with your machine gun by
pressing the joystick fire button, thus gaining an additional 50
points and being able to carry on with your search. If you kill an
enemy, another will immediately come looking for you. Remember, they
are not stupid and, since they carry a machine gun as well, they will
shoot at you as soon as they come within range.
Some additional
features: You lose a man either by being shot or by running out of
time. With each level the enemy action is faster, there are more
bottles to be picked up, and the enemy gangsters will chase you more
precisely and relentlessly. There can be some nasty shoot outs between
you and any intervening bottles! You can shoot bottles out of the way
but there is no score for spilt liquor! A high score is incorporated
and, at the end of the game, options appear set at the previously
selected figures.
The game features a
very colourful main screen (10 colours) obtained by prolific use of
Display List Interrupts initialised in machine code. It is essential
to type in the title page in inverse video where shown in order to get
the DLI cycling of colours there.
Background sound during
the game is achieved by means of more machine code operating as a
Vertical Blank Interrupt routine and great care should be taken in
ensuring that the program is correctly typed in order to avoid
crashing the system. The safest course of action is to SAVE the
program before running it.
There are many
variables in the program, thus allowing it to fit in 16K. It should be
noted that O=0 and that this alone saves approximately 900 bytes of
memory! The program will probably still work in 16K if the occasional
0 (zero) is typed instead of 0 but careful attention should be paid to
this point.
There is a very smooth
transition from the `READY' prompt to the main screen achieved through
page-flipping.
When RUN the screen
will go blank for about 6 seconds which is very fast considering that
initialisation consists of the transfer (in machine code) of half a
character set from ROM to RAM, redefinition of characters, setting up
of a lot of variables and the implementation of multiple DLI/VBI
routines.
Enough reading! Get that liquor and be
prepared for a shoot-out!
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MAIN VARIABLES
B
50 points character
BO
Bottle shape
CL
Clear floor check
DL
Beginning of display list
E
Door exit screen display
EL
Floor colouring determinant
G
Enemy gangster screen position
GB
Character behind enemy gangster
GC
Enemy gangster climbing
GD
Enemy gangster vertical position
GK
Enemy gangster killed?
GL
Enemy gangster facing left
GR
Enemy gangster facing right
GS
Enemy gangster's shape
HI
High score
I1
Low memory DLI pointer
I2
High memory DLI pointer
IE
Interrupt request enable location
L(
Level for each player
L
Ladder shape section
LE
Level
LM
Left margin of screen
4ctbM(
Number of men each player
ML$
Machine language for transfer of character set to RAM
MV
Background music/sound volume
NP
Number of players
P
Players screen position
PB
Character behind player
PC
Player colour
PD
Players vertical position
PL
Player shape facing left
PR
Player shape facing right
PS
Player's shape
RM
Right margin of screen
S(
Score(s)
S
Joystick
SO
Setcolor 0
S1
Setcolor 1
S2
Setcolor 2
S3
Setcolor 3
S4
Setcolor 4
SC
ANTIC enable/disable
T
Time
V0
Voice 0 distortion location
W
First screen display location
WA
Wall shape
X
Move of player
XT(
Extra player
Y
Move of enemy gangster
