SURVIVOR (16K ZX81)
by Adrian Spriddell
from Your Computer (May 1985), Pages 78-80

This is a ZX-81 graphic adventure game call Survivor containing 10 levels
each with its own different screen display and running in under 5K of
machine code including all data. And before you reach for a calculator, I
know that it takes 7K to score 10 screens. The discrepancy is due to the
effects of Bistromatics, the original program having been written on the
back of an old restaurant menu.

You are a lonely little blue person with short spindly arms having next to
no strength so you cannot hang from anything. You are, however, possessed
of a pretty good pair of legs - good that is for running and jumping.
Unfortunately, the standard ZX-81 graphics set is somewhat limited and most
little blue people end up looking suspiciously like a capital A, and on
most televisions, worse still a black and white capital A.

You have absolutely no defence's or protection. Almost anything in your
environment is hostile. In fact, about the only thing that will not harm
you is stepping on the cracks in the pavements.

Apart from flying bricks, arrows, boulders and anti-matter bombs being
hurled at you, mummies, ghosts and horrid guards with sharp spears - OK
then, dollar signs - are running around and will kill you if they get half
a chance.

Not even the ground is safe entirely. Black blocks are OK and may be walked
on or through with impunity but anything else black should not be trusted.
There are grey seams of gold Windscale waste around. These are impenetrable
and although not immediately fatal, should you step on one, you will lose
50 health credits and have to start again. Bridges and elevators are there
to help you - usually. Keys are: P - left; O - right; Shift - jump.

The object of your endeavours is to reach the inverse star which is the key
to the exit. Once this has been achieved you will be awarded 100 points and
the exit itself will appear an another inverse star. This is your way
through to the next level. Any time points then remaining will be added to
your bonus. If you fail to collect a key or reach an exit before the time
count reaches zero you will lose a life but will be able to carry on -
assuming that was not your last life - where you left off by pressing any
key.

Keys Y, H or B will suspend the game while you grab aspirin and a coffee.
Pressing any other key will restart play.

The game contains a number of variables initially set to nominal values but
which may be Poked to effect changes as shown in table 1.

Table 1.

Address  Nominal  Parameters  Function/notes
         value
16674    204      see note    Wait key. Change to 202 for Break key
18863    61       see note    Change to 0 for infinite lives
17021    3        2 to 5      Speed. Increase to slow play
17287    0        0 to 9      Level
19050    50       0 to 250    Grey block penalty points