Computer-games have been around nearly as long as the computer itself.
One of the first games I came across was tic-tac-toe, which was brought to our System/3
installation by the IBM CE.
It was implemented as a rather small program using a large direct file on disk.
The file contained one record for each possible move, so someone has used quite some
time on this subject.
The records contained a field with the image of the 3 x 3 matrix of the game.
Then there were nine fields with the relative record number of the next record selected by
the user input 1 to 9 which specified which cell he would place his “X” or “O” in, entering
zero would end the program.
It looked something like:

4  5  6
X  8 O

Select cell?

                                                = = = o O o = = =

My favorite game is still MasterMind.

It is a game where you shall guess the color combinations of four pins, which each can
have anyone of six colors or be omitted/blank. It is allowed to use the same color more
than once. As I at that time played the “real” game a lot with a friend we had an idea of
how this should be handled.

Normally the computer-game is so that the user has to guess what the computer has
selected, but I think the opposite is more challenging, at least as a programming exercise.

I first implemented it on a model 6 where all the 2401 possibilities were written as records
on disk, then as the user entered the white and black “answer-pins” (for correct color in
correct position and correct color but in wrong position) the possibilities which was now not
valid was marked and the next could-be valid possibility presented to the user.

The first version sometimes took ages to come up with at new guess.
But later the implementation was changed so the possibilities was generated on the fly, but
that still to quite some time on a System/3 and later on a System/32.
It was funny to see how it looked as “artificial intelligence” when trying to come up with the
right answer.

I have later implemented the game in BASIC for the PC and JAVA for the PC and my
mobile-phone. I was curious to see how fast it would run on a mobile-phone using JAVA,
which is an interpreted language, but there is no noticeable delay, so the CPU-power of
even the smallest electronic today is superior to what we had then.

On the other hand was it amazing what was possible then with the slow CPUs, tiny
memories and small and slow disks compared to today’s standard. But I think one of my
favorite expressions “Better software is a lot cheaper than more hardware” will continue to
be true.

                                                 = = = o O o = = = 

Another game I programmed, but with inspiration from others I agree; was JackPot for the
3277 display. You were “debited” one Danish Krone when you pressed enter and the
computer would “turn” its three “wheels”. If you got one of the winning combinations (e.g.
123 or three of the same kind say 555) you got a “credit” of some amount. Your where
able to “hold” one or two of the wheels by using the PF-keys. The important part was to set
a reasonable credit-table as it should not be too easy or to difficult to win as the excitement
would then have been gone.

My interest in computer games was and still is to implement them and see them work.
After that I lose interest, but others take over and play the games.

I remember one time when a colleague in accounting liked to play Jackpot when having a
break. Unfortunately he was playing when his boss went out for a meeting in the morning
and he was also playing when the boss came back in the afternoon. We, in the it-
department, was then asked to remove the games from the system.

                                                = = =  o O o = = =

I also implemented the HangMan game, where you should guess a word within six tries.

If you entered a letter which was not in the word the hangman was one part (head, body,
arms or legs) nearer to be hanged. I took all the reserved words from COBOL as the
words to guess. The “graphics” at that time looked something like:

|      /|\
|      / \
It is fantastic what has been done on the graphics since then!

                                               = = = o  O o = = =

The last computer-game I remember from that time was Lunar Landing.
Remember that it was in the days of the Apollo-flights.
You had a given quantity of fuel, and were asked to fire the rocket.
The new speed toward (or maybe the opposite if your fired to heavy) and distance to the
moon-surface was calculated and you was asked again.

It continued until you either ran out of fuel or touched the moon, either by a heavy impact
or maybe a perfect landing.
To this game there also was some primitive graphics which should represent the “eagle”
lunar landing vehicle.
                                               = = = o O o = = =

Computer games has come a long, long way since that time!
Now you nearly cannot see if it is pictures from the news or the latest action game which
runs over your screen.