Balloon Hopper - Andrew Foord (Your Computer-September 83-Page 76)

On September 19, 1783 curious spectators, including Benjamin Franklin,
watched the launch of the first passenger-carrying balloon. There were
three passen- gers - a sheep, a duck and a rooster and the flight
lasted for eight minutes. To celebrate the 200th anniversary of this
aeronautical feat Andrew Foord de- tails a simple arcade-type game for
the Spectrum.

LIFE IS HARD at the spaceport, especially if you are the pilot of
Balloon Hopper. You control a cargo hopper, a small flying transporter
capable of lifting one piece of cargo at a time. The hopper is used to
load the space- craft at the top of the screen with any 10 pieces of
cargo that can be found at the bottom. Each piece of cargo loaded
scores either 50 or 100 points and there is a bonus of 200 points for
each ship fully loaded.

Sounds easy? Unfortunately you have picked the wrong day to be the
pilot be- cause there is an air-day nearby and stray balloons keep
floating in your way and hindering your job.

Each time you hit a balloon the explosion caused by the
hydrogen-filled bal- loons weakens the hopper's force-field. You can
survive four hits before your hopper can no longer function.

Initially there are three balloons in your way; this increases by one
for each starship you load. You move using the cursor keys and you
must land on top of a piece of cargo to pick it up. To drop the cargo
you simply take it to the top of the screen avoiding the balloons on
the way.

The program is written in Basic but contains a machine code routine
which is Poked into memory from data statements when the program is
first run. The machine code routine moves the balloons making the game
much faster than if just using Basic program. As the data is Poked
into the memory the computer compiles a check-sum so, if you have made
a typing error in the data state- ments, the computer should notice
and warn you.

The program uses all 21 user-definable graphic characters and these
are shown here. Graphics G to L do not appear in the listing because
they are only used in the machine code, not the Basic part. The
program is set out as follows:
        
5- 110 Set up game 200- 350 Set up screen 400- 490 Main game routine
500- 530 Cargo dropped 1000-1070 Life lost and end of game 2000-2090
Instructions 5000-5030 Poking in machine code and UDGs 7000-7095 UDG
data 8000-8050 Machine-code data

To have more balloons at the start change LET Z=3 in line 100 to
whatever you want. To have more than one extra balloon appear after a
ship is fully loaded change line 527. To change the control keys
change line 410.

TYPE: Arcade


This info file was typed by Michael Bruhn


Correction from YC Oct'83, page 47 (included)
----------------------------------
Some of the graphic characters in the Spectrum Balloons program have
not been clearly printed. In line 480 the characters are graphics Q
and graphics S, while in line 515 the character is graphics S.

