Racing the Beam : the Atari Video Computer System - Index of

“original” concept needed to be devised at Atari in the heyday of VCS
programming, from 1977 through 1983, it would be the work of a programmer,
not a task force.
Although many elements may have dropped off the wish list that
Parker Brothers’ team developed, Star Wars: The Empire Strikes Back built
upon fi ve years of VCS development to include features that would have
made jaws drop at Atari back in 1977. And it was devised by a programmer
who not only was working at a different company—he had never worked at
Atari. How did this programmer, Rex Bradford, learn to develop VCS
games? He explained: “Our fi rst job was to reverse-engineer the tradesecret
Atari [VCS]. Parker Brothers hired a company to strip off the top of
the graphics chip and photograph it. [Two engineers] stared at the circuit
diagram, while I wrote a disassembler to examine existing cartridge code.
Then I started writing some small programs to test our theories about how
it worked. Finally, by the fall of 1981, we were ready to create our fi rst
game.” 8
In some ways, the fi rst game that Bradford completed resembles
Eugene Jarvis’s 1980 arcade game Defender, which was ported to the Atari
VCS in 1981 by Bob Polaro. Star Wars: The Empire Strikes Back is also a
smoothly side-scrolling shooter in which the player’s small ship, the
snowspeeder, can move left or right along terrain, wrapping around the
playing fi eld (fi gure 7.3) as can be done in Defender. The same type of
long-range view of opponents that this earlier game offers is also present
in Star Wars: The Empire Strikes Back. But beyond that, there are signifi cant
differences. There are no people running around on the ground who need
to be defended from abduction. Whereas Defender has a host of different
enemies who behave very differently, Bradford’s game has only the
massive Imperial walkers. These can fi re two types of weapons, one ballistic
and one “smart.” Both types of enemy fi re can be shot down by the
snowspeeder. The snowspeeder can also land and a limited number of
repairs can be undertaken. The level of damage to the snowspeeder and
to walkers is indicated by their color, which shifts through green and red
into yellow.
The Imperial walkers are visually and formally formidable. They are
drawn in a rather elaborate way. A sprite scaled at 4× is used for the body
of a walker, in the top half of the screen. Then, a sprite scaled 2× is situated
directly below to provide the legs. Both are effectively eight “pixels”
wide, although the sizes of these two pixels are not the same, so that the
top half appears twice as blocky as the legs. This technique makes it easy
to make the body “solid,” while the legs are not. The effect is an opponent
whose Imperial scale dwarfs the Rebel snowspeeder, effectively evoking
7 Star Wars: The Empire Strikes Back [129]