LINC PROGRAM -- SPACEWAR (SPCWAR) Function: Spacewar is a simple two-player game of tactics, straight shooting and good old-fashioned luck. Two vehicles (rockets) are maneuvered by the players and missiles may be launched to destroy the opponent. Operation: Each vehicle is controlled by two knobs on the master oscilloscope module. One, designated the left vehicle, is under the control of knobs 0 and 1, and the other, the right vehicle, is controlled by knobs 6 and 7. Each knob determines both direction and velocity; the center position of each gives no movement while the extreme positions give maximum velocity in opposite directions. Knob 0 (or 6) controls movement in the X axis (left and right) and Knob 1 (or 7) controls movement in the Y axis (up and down). Combinations of settings of the X and Y Knobs give the vehicle freedom of movement in any direction. The action takes place in one plane of "hyperspace" which the vehicles never leave; the upper edge of the plane is continuous with the lower, and the right edge adjoins the left. A single missile can be launched from each vehicle by operation of sense switch 5 (left vehicle) or sense switch 0 (right vehicle). Momentary raising of the sense switch launches the missile on the current heading or direction of the space vehicle's movement at a velocity twice that of the launch vehicle. The velocity and heading of a missile once launched, is independent of all subsequent maneuvers of the launch vehicle. The missile is not armed until it has LINC PROGRAM -- SPACEWAR (SPCWAR) -2- moved a set distance from the launch coordinates; hence, laying down of a stationary missile (or mine) is not feasible. Each missile has a fixed duration life expectancy of 191 display cycles which give it a minimum range of about 75% of the screen diameter at minimum velocity. After launching, the missile can be destroyed by raising of the sense switch. A missile will destroy, permanently, either vehicle, friend or foe, if it comes within the limits of the proximity fuse. The two vehicles will also annihilate each other if they approach too closely. After the explosion, the remaining vehicle can still be controlled by its knobs, except, of course when both have been mutually destructive. After a kill has been announced by the explosion, the entire game (program) must be reloaded into core memory from tape. This is necessary since the explosion also involves extensive destruction of subroutine linkages. Modifications: The shooting accuracy needed can be adjusted by changing the SCR instruction, tagged 7Z, located at manuscript line 750. If the SCR is increased to SCR8, shooting may be extremely sloppy; if decreased to SCR3 , the game becomes a suitable test for aficionados. Masochists may add flavor to the game by opening up hyperspace (that is, all eight possible display planes) by changing each of the following masks, presently 7000, to 0000: Manuscript lines 20, 30, 40, 50, 157, 165, 177, 205. LINC PROGRAM -- SPACEWAR (SPCWAR) -3- Curious effects may sometimes be experienced by pilots who launch missiles at the instant they cross the equator! Further modifications can involve changing the controls to SAM instructions at the data terminal box and substituting skip-on-external-level lines for the sense switches. Tags: Tags prefixed with 4, 5, 6 or 7 are used in great numbers. Check carefully before adding more. A. J . Hance, April 1965 ---- Bernard Lechner papers, Hagley Museum, M&A 1192, folder 15 Magnavox v. Sega, Defendant's Exhibit HANCE 12; MS176068, MS176069, MS176070 Transliteration: Norbert Landsteiner, April 2021