Bits and Bytes OnLine: OXO for the win

Friday, July 22, 2022

OXO for the win

Across the pond in Britain, 70 years ago, someone played the first electronic video game pitting a human against a computer.

Digital calculating computers with electronic functionality, programmability, and memory-storing were engineered and built in earnest shortly after the Second World War.

In 1947, British computer scientist John Maurice Wilkes assisted designing and constructing the digital Electronic Delay Storage Automatic Calculator (EDSAC) computer in the mathematical laboratory at the University of Cambridge in England.

EDSAC is a name many have forgotten, but folks should remember it as the first practical stored-program control digital computer.

With over 500 square feet of 12 vertical racks, EDSAC contains 3,500 electronic vacuum tubes and mechanical enclosures containing refreshable "mercury ultrasonic delay lines" for the computer's 512 (17-bit per word) memory.

Mercury was used because the element's acoustic impedance mimics piezoelectric quartz crystals, which convert mechanical energy into electricity.

On the computer's monitoring desk sits a rectangular, metal display cabinet measuring roughly 2 feet by 2 feet.

The cabinet contains three electronic VCR97 curved cathode-ray tubes (CRT) display/status monitors.

The 9-inch diameter CRT monitors are labeled: counter, memory, and sequence control. These picture tube monitors are wired into the computer.

The monitoring desk also held an electromechanical paper tape reader. The reader inputs data into the EDSAC computer using a five-hole punched teleprinter paper.

The tape reader operated at 6 2/3 characters per second.

A British-made Creed tape-printing teleprinter working at a speed of 50 baud (about 66 words a minute) sits on the monitoring desk, receiving output data from the EDSAC computer, which executes instructions at a rate of 500 kHz.

A magnetic tape drive unit was added to the EDSAC but did not function accurately enough to be used during data processing.

Electronic thermionic valve logic tubes processed up to 650 programming instructions per second, which is not too bad considering this was 73 years ago.

On May 6, 1949, "Machine in operation for the first time," read the handwritten log entry from the University of Cambridge's mathematical laboratory.

Mathematicians and researchers were pleased while analyzing the first results of the programming instructions compiled and completed by the EDSAC computer.

I noted how EDSAC processed data similar to telephone calls of the day being routed using step-by-step electromechanical switching platforms with relays, vacuum tubes, connectors, selectors, and extensive wiring.

"Scientists at Cambridge University are about to unveil a thinking machine with a brain that weighs a ton. It [EDSAC] can do 15,000 arithmetic problems a minute," the St. Louis Missouri Star and Times newspaper reported June 17, 1949.

British Professor Alexander "Sandy" Douglas used the power of the EDSAC computer while writing his thesis on human-computer interaction at the University of Cambridge.

The EDSAC provided real-time results and proved his human-computer interaction thesis findings by successfully executing Douglas's programming code for a simple game whereby a human competed against the computer.

In 1952, Douglas completed the programming for a human-computer game named OXO, which we know as Tic-Tac-Toe.

Sitting at the computer's monitoring desk, the human plays the game using a rotary telephone dial wired into the EDSAC computer. The rotary telephone dial functions as the OXO game controller.

I hear the young folks asking, "What's a rotary telephone dial, grandpa?"

But I digress.

When using Douglas's OXO program, the human user dials a digit on the rotary telephone dial from 1 to 9 to represent where to place an X or O on the tic-tac-toe board shown on a CRT monitor to the right of the rotary telephone dial.

The human player's move appears on the monitor, followed by the computer's response move being instantly displayed.

The computer and the human player take turns placing either an X or an O on the board.

The display screen updated every time the state of the game changed, allowing a player to make their next move until there was a winner.

People in or near the University of Cambridge's mathematical laboratory played the OXO computer game.

Although Douglas created the OXO game for research, it has been acknowledged as one of the first electronic computer games with interaction through a display screen.

Some have also said Douglas's OXO gaming program was one of the first practical uses of artificial computer intelligence.

Douglas's thesis on human-computer interaction was a total success. As a result, he earned a Ph.D. and continued his life-long career in computer science.

To view a screenshot of an EDSAC simulator running the OXO game, go to https://bit.ly/2QLbrh8.

The original EDSAC was decommissioned in 1958, but its webpage is at https://www.tnmoc.org/edsac.

John Maurice Vincent Wilkes was born in Worcestershire, England June 26, 1913. During World War II, while serving in the Royal Air Force, he worked at the Telecommunications Research Establishment. In 2002, he became an emeritus professor at the University of Cambridge.

Wilkes passed away at age 97 Nov. 29, 2010.

Alexander Shafto "Sandy" Douglas, recognized as the creator of the first computer video game program, was born in London, England, May 21, 1921.

Douglas passed away at age 88 April 29, 2010.

And yes, they died seven months apart on the 29th day of the same year.

I want to end today's Bits and Bytes by thanking David for letting me know he reads my column and that I enjoyed our conversation about computers, programming, and telecommunications.