WINDMILLS (16K ZX81)
by S J Bennett, Scarborough, North Yorkshire
from Your Computer (September 1982), page 97

You have been sent by your firm to an island in the Outer Hebrides. Your
task is to build windmills in the most profitable areas of the island. For
each mill you build, you receive one lorry to transport corn and coal, to
and from the mill.

Try to build your mills in areas where the wind conditions are good, and
therefore use less coal for the donkey engine. The maximum number of years
you can stay on the island is 50. For each year you stay you are given a
report of the cost of coal, petrol and other expenses. Be careful of the
price you charge per bag of corn as the farmers may argue with you. When
you decide to leave, you are shown the net income for each year, and then
a total for the full period on the island.

The island has been split into co-ordinates A to P inclusive, and 1 to 8
inclusive. To enter a mill, type number first, then letter. After entering
your positions, you will be shown a display of weather conditions.

    1  3P  Windswept Area
    2  4A  Sheltered Area
    3  6M  Windy Valley

The first column is the mill; the second column the location; and the third
the weather conditions for that area. After the weather conditions, you can
alter the locations of any of your mills, or ask for a report on mills
already built.

Here are the variables used.
   A = Control variable
   B = Control variable
   C = Coal used
   H = Corn harvested
   P = Petrol used
  MW = Miller's wages
  TA = Total expenses
  AE = Charge per bag
 YRT = Total years on island
  TC = Total coal used
  TP = Total petrol used
  XX = Tax paid
  ZA = Random number * 10
  ZX = Gross earnings
D(B) = Distance variable
X(B) = Letter co-ordinate
Y(B) = Number co-ordinate
Z(B) = Co-ordinates of mills built