Early IBM mainframe computing.
Computer gaming on early IBM mainframes was indeed possible and was common if the installation allowed it.
In the early 1970s I worked for a major airline, and we had redundant IBM 360s and then 370s. Memory was initially 256 KB and then 512 KB. One machine was the online reservations machine and the other was used for backup and testing.
As a computer operator working shifts, the lucky ones assigned the graveyard shift had access to the test machine almost all night. We would play around with the machine, learning IBM assembly language programming or Fortran.
The input/output device used by the control operator in those early days was an IBM 1052 console, essentially an IBM Selectric typewriter, which the O/S received commands from and typed to. We had IBM 1403 printers for bulk job output.
Programs and the associated control “wrapper” JCL (Job Control Language) were 80-column cards, produced on a card punch machine. Tape storage was 2400 series magnetic tape. Disk storage was 2314 disk storage units, each disk holding only about 30 MB of data. By the early 1970s, paper tape was on its way out.
The two most common games were Star Trek and Hammurabi. Each, if I remember correctly, was written in Fortran. They were text-based.
Star Trek was the familiar 10x10 dot grid, ten of them in which each was a sector of the galaxy. Picture a 10x10x10 cube. You would navigate through the sectors killing or avoiding Klingons.
Hammurabi is best described by Wikipedia. “Hammurabi is a text-based strategy video game centered on resource management in which the player, identified in the text as the ancient Babylonian King Hammurabi, enters numbers in response to questions posed by the game. The resources that the player must manage are people, acres of land, and bushels of grain.” The game unfolds year by year as you manage your kingdom.
The game, on 80-column cards, would be read into the machine through the IBM 2540 card reader. Once running, it would interface directly with the 1052 operator console. Commands could be entered via the 1052. It also received text output from the games. Towards 1975, CRTs became more commonly used on the mainframes, and they could be used to play these two games as well.
By the latter part of the 1970s, for a number of years we had Perkin-Elmer time share terminals. They came with their own BASIC interpreters where one could write and run BASIC code right from the terminal itself.
Early on in the 1970s, I wrote a tic-tac-toe game which ran on the mainframe. My plan was to make it a self-learning game, in which the human operator would play the computer. The computer would initially make random moves and if it lost, it would save the losing game board pattern to tape at the point just before it made the losing move. So each time you ran the game, it would read in the tape of losing moves, and never repeat that move again. After about 400 games, the machine never lost, and the best you could do against it was a draw, depending on who had the first move.
In the later 1970s vector graphic CRTs were purchased, which were used by the computer operator in place of the IBM 1052 system console typewriter. A friend of mine, actually a brilliant IBM engineer, wrote a space shooter game, where two ships flew around the CRT monitor and, using the keyboard, you could shoot at one another. This was only in use for a short time, as management then decided to kill all game playing on the company mainframes.
So there you have it.
