First Graphics Game written on and for a Home Computer
For a 22 second sample video of the game on youtube, click here.
Today many computer enthusiasts write programs at home for their own graphical games. It's fun. This page documents the first graphical computer game written at home on capable home computer hardware. It turns out that both the game software and the computer hardware were created at home by three brothers all in college in the mid '70s.
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The video shown is a short clip from the operation of the world's first graphical computer game written on and for a home computer. It was written and operational in 1975. The famous game creator Scott Adams wrote this game. Scott's public claim to fame is from his original Adventure game series and other items that he sold through the company he founded called Adventure International.
The claims here that Scott and Richard were the first at doing these things are specific. Some of the historically significant claims by others for different "first of their kind" computer / graphics / games are noted herein below.
The 22 second youtube video clip depicts the playing field that uses alphanumeric characters as game elements. The letter E was the Starship Enterprise, while C was the opposing player's ship. The asterisks shown moving on the screen are hazards such as meteors. Stationary hazards appearing as a circle with satellites in geosynchronous orbit are planets. The plus signs are photon torpedoes fired from either of the opposing ships. A still shot of a different scene than depicted in the video that has both ships firing weapons is shown below.

Game play frame from the World's first Home Computer Graphics Game
This was a two player game where both players courteously shared one computer keyboard. Players pressed keys on the keyboard to move their ships and fire weapons. Although the computer had an alarm buzzer under program control, there wasn't an audio output for the game.
Since the word Klingon starts with the letter "K," Scott was asked to explain why a "C" was used. His response was that the "K" didn't look as good on the playing field. Not all of the motion, hazards and weapons are depicted by this short video. The game allowed for a good battle for the technology at that time, within the constraint of an inventive though thrifty college student's budget.


World's first 16 bit home computer built in 1974 by Richard Adams
The above two photos were taken in 1975. Shown in the photos is the computer chassis, keyboard and monitor screen. This computer was designed and built by Scott's brother Richard Adams starting in 1974. The computer was based on a National Semiconductor IMP16 chip set that consisted of five LSI chips. The IMP16 was commercially successful, being used in aircraft and also within automotive engine analyzers made by Sun, as examples. Single chip 16 bit microprocessors were announced as early as 1974 but did not ship until several years later.
Since early commercial home computers were all 8 bit designs, the technological prowess of Richard's home built computer was years ahead of 8 bit commercial home computers that just started to be available to enthusiasts in 1974 and 1975. Examples are provided later in this page.
Home computers of the 8 bit flavor which included built in graphics that could actually be marketed to home users beyond the level of hobbyists began to ship in 1977.
Scott's game used the original graphics interface of the computer that Richard modeled after the design of Don Lancaster's TV typewriter presented in the Radio Electronics Magazine in 1973. It had a display of 16 lines of 32 characters each. Scott's first game, documented here, was written with the original 16 x 32 non-bitmapped layout.
Different from the usual Radio Electronics magazine TV Typewriter design, in Richard's innovative implementation, the IMP16 processor had an extremely fast direct access to the memory of the display adapter, allowing for rapid updating of the display. This fast access to the display memory made Scott's game possible. It would not have been possible if the typical serial interface was used. Most of the boards in Richard's computer were hand wired point to point between the chips or sockets. Soon after Scott's first game was written, Richard updated the IMP16 graphics system with twice the number of characters and a bit mapped display that he first applied to provde a real time display of vibrating strings in motion using equations applied from his college courses.
The "on screen" display in the photo above showing the words "Adams IMP16" were generated by a computer program written by Scott's other brother Eric Adams. It was a banner display program called "Bigchars." Eric also wrote the program that allowed using the keyboard and display screen to enter and edit data directly into the computer's memory. This was much more convenient than using the front panel binary switches and display LEDs to edit programs, which is what Scott had to do for most of the work on his game. Eric also built one of the point to point wired circuit boards for Richard's computer. Richard designed and built most of the computer and wrote the O.S. and programs that saved and recalled data on the cassette drives, and other programs.
The Keyboard used on the computer was the $40 unit from the TV Typewriter kit as archived at the wikipedia page. Scott attached paper tags to the keyboard keys which had arrows to identify the directional control of the space ships and weapons that those keys represented. These paper tags are visible in the photos.
Scott was out of the country for an extended employment stay when Richard first built the machine and got it working. When Scott returned, he was excited about having a computer at home and made the game. The game is hand coded in assembly / machine language for the IMP16 microprocessor. The actual code is 14 pages on loose leaf notebook paper. The original is still intact. A portion of one page of this is shown next in the photo immediately below.

28 bytes of the actual game program hand coded by Scott Adams in 1975
Click to see the entire hand coded manuscript from 1975

This first and only one of its kind manuscript was last
purchased by a private collector in 2005 for US $197,500.
That's the year of authorship times 100.
To own it yourself now, contact the collector through
the librarian at the link at the bottom of this page.


It has been suggested that the intact program in the manuscript be replicated and made into an emulation of the game to run on modern hardware. The manuscript contains the one of a kind and first graphic game written for a home 16 bit computer, and is also the first such game written by Scott Adams for Richard's computer. Notice how Scott's code uses labels corresponding to the game's action such as "Fire" torpedoes and speed of ships, weapons and obstacles.
The entire game was about 1000 computer bytes in length. It was a brilliant use of the hardware and top notch coding efficiency. Programs of early computers demanded that efficiency due to main memory being expensive and the lack of inexpensive access to hard drives for virtual memory.   The image of the entire source code manuscript hasn't been published yet.
Richard allocated most of the time for using his computer to his own use. Scott wanted his own computer and made arrangements to buy his own Sphere brand home computer in 1976. Prior to leaving Florida for Silicon Valley, Richard gave Scott some pointers to assist Scott's design of a bit mapped graphics controller for the Sphere computer. Scott wrote a bitmapped graphical Tank battle game and made custom game controllers for two players. This may be the first bitmapped graphics game written at home for a home computer. Archived photos or video of this game are still be sought.
The game for the IMP16 computer was written by Scott when the three Adams brothers lived together in Scott's house that was about half way between nearby Cape Kennedy and the college the three of them attended in Florida in 1975. The video portion of the recording of the game play was made in 1979 when Richard first got an RCA VHS VCR. Richard was living in San Jose California at that time, having moved there from Florida upon his graduation from college in 1976. Richard continued to improve and use the computer until 1983.
In 1979 Richard connected the computer's NTSC video output to the new VCR's video input. The voice was dubbed in some time after the video recording was made. The IMP16 computer system is still complete and intact and has been in storage since 1983.
The Adams brothers referred to the game as Scott's Space Wars. The exact claim that this is the first home graphics game is specific to 16 bit home computers built or purchased for home use and programmed in the home. It is remarkable since the game author Scott Adams started Adventure International soon after writing this game. Also remarkable were the inventions Richard made while in college and while he worked for other companies in Silicon Valley. He also started his own company called Happy Computers in 1982.
It is likely that Scott's game for the IMP16 was also the first graphics game written at home for any home computer, including 8 bit and others. Please contact the librarian at the email address shown below if you have information to the contrary.
The Mark 8   8008 based computer was announced in July 1974 and the Altair 8800 was announced in January 1975 based on the 8080. Both were 8 bit computers, it is possible that an 8 bit home graphics game was written near the same time that Scott wrote his game in 1975. There's been no known announcement of this, nor supporting documentation and video as there is for Scott's game.
Speculating, the only 16 bit computers that might have found their way into homes would have ultimately been connected with academic or commercial non-home use and budgets. There were no high speed access video cards sold ready made for these 8 bit computers prior to Scott writing his game. The high speed video for the IMP16 was Richard's brainstorm. There were a few graphical computer games published in hobbyists magazines in the late 1970's, years after Scott wrote the first and got it working.
The following distinguished "first of their kind" computer gaming achievements are also recognized. Written in 1952, the first computer graphical game was the called OXO, a tic-tac-toe game for the EDSAC computer at the University of Cambridge. The first game of a similar name to Scott's was Spacewar!   Spacewar! was written for a PDP-1 computer at MIT and working in 1962.
Stanford University had its own a unique multi console coin operated game in 1971 called Galaxy Game.   A few months later in 1971, the first commercially produced coin operated arcade game console was the 1971 game Computer Space.
The first home graphics game console was the Magnavox Odyssey. This game console had no computer capabilities for the home, and was not programmed in the home.
Click for Scott Adams official Wikipedia Biography
Click for Richard Adams official Wikipedia Biography
After working for three Silicon Valley Companies over six years, one of the companies Richard formed was Happy Computers.
For details of events that led up to Richard Adams building the IMP16 computer including his computerized music sequencer invention that appeared in a 1974 newspaper article click here.
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5/5/09 - "Dan" Lancaster corrected to Don Lancaster.