The algorithm used is to collect the following pairs of the user's color selections: 1+2, 3+4, 5+6, 7+8, 1+8 It then looks up a message for each pair of colors and prints it. Button equivalents: 80H left button 1 Blue 40H left button 2 Brown 20H left button 3 Black 10H left button 4 Yellow 08H right button 1 Violet 04H right button 2 Green 02H right button 3 Orange 01H right button 4 Gray Overlay layout: Brown Black Blue Yellow (Note: Orange and green were apparently reversed 25c when the overlay was printed. They were Violet Gray not switched inside the program, but were rewired on the PCB itself, therefore they Orange Green do not match the screen display!) The potentioemeter inputs are not used. The coin slot is rigged up to pin 35 of the cartridge slot. Apparently a logic low indicates that a coin is passing between the optical detectors. ROM is from $0000 to $7FFF, battery backed RAM is at $8000 to $87FF, and the LEDs are set by a write to $A000. The LED bits match the button bits. To get into set up mode, hold down the blue button and turn the Vectrex on. Note that on a reset but not power-up that the "high score" is the total count of coins inserted into the machine. After the game start screen, the screen will be black. While holding down the blue button, press and hold the desired button sequence, then release the blue button, then release the other buttons. Setup mode with "WORDS" screen: yellow+violet+gray Setup mode skipping "WORDS" screen: orange+green You can also get to the startup screen by holding down brown+black+yellow at the same time when it is asking you to select colors. You can also reset the Vectrex to read the coin counter by holding down yellow+gray. You can also hold down blue+violet when inserting a coin to reset the Vectrex, and brown+black+yellow when inserting a coin to enter setup mode. In the WORDS screen, you are setting up the initial display in the attract mode. This will be a series of 6-character lines drawn with large vector letters. You can use A-Z, 0-9, ".", and "$". All other characters will display as blanks. See the chart for entering characters. The next screen is the "SCROLL" screen. Press blue for fast scrolling, or gray for slow scrolling. The next screen is the "CONTINUOUS MUSIC" screen. Press blue to disable background music, or green to enable background music. The next screen is the "# COINS" screen. This lets you select the number of coins-per-play required. 1 Black 5 Green 2 Yellow 6 Violet 3 Gray 7 Blue 4 Orange 8 Brown The last screen is the "ADS" screen. This is displayed at the end of the user's color choice "analysis", right before the copyright message. Each character requires two button presses. Here is the chart for entering characters: 0 gray gray G green gray W yellow gray , brown gray 1 gray orange H green orange X yellow orange - brown orange 2 gray green I green green Y yellow green . brown green 3 gray violet J green violet Z yellow violet / brown violet 4 gray yellow K green yellow yellow yellow : brown yellow 5 gray black L green black ! yellow black ; brown black 6 gray brown M green brown " yellow brown ? brown brown 7 gray blue N green blue # yellow blue = brown blue 8 orange gray O violet gray $ black gray BS blue gray 9 orange orange P violet orange % black orange CRLF blue orange A orange green Q violet green & black green up blue green B orange violet R violet violet ' black violet down blue violet C orange yellow S violet yellow ( black yellow left blue yellow D orange black T violet black ) black black right blue black E orange brown U violet brown * black brown home blue brown F orange blue V violet blue + black blue end blue blue (twice) "Magic" button summary: Setup mode: startup+blue -> yellow+violet+gray color screen+brown+black+yellow coin+brown+black+yellow Setup mode, skip "WORDS" screen: startup+blue -> orange+green Reset: color screen+yellow+gray coin+blue+violet Exit text entry: press blue four times - - - RAM LAYOUT: 8000 W 8002 (6 bytes) coin counter 800A 8073 876C 876D 87F9 87FE B Number of coins per "play" 87FF B $00=fast scroll, $07=slow scroll, +$80 = continuous music clear C883-CBC4, CBC7 C883 8 bytes color choices C88C B cnt C88F W adr C8xx C88F B C890 B C891 B C891 W adr C892 B C893 W adr C9xx C893 B ypos C894 B xpos C896 B cnt C897 B cnt C898 B ypos C898 B selected color bits C89B B C8B7 B C8B8 B C8B9 B C8B7 5 bytes color pair indexes C8BE B (copied from $C8C0) C8C0 B (copied from $87FF) C8C4 W adr color choices array pointer C8C6 W adr C9xx C8DA W adr C8EF B C8F8 B cnt C900 CB71 W attract LED state, hi byte = timer?, low byte = current flash CB81 W adr 8xxx CB83 W adr 8xxx CBC6 B state of coin slot at startup? CBC7 B credits counter CBEA stack CBEB-CBF0 "live" coin counter (high score)