I wasn't entirely sure about the ic numbering, #44 is indeed an unrelated component (it's a decoder chip used for the displays) and the gating chips are 45 & 50, '7402' Quad NOr Gate. The four separate gate circuits of U 45 operate 'special' solenoids 1 to 4, while U 50 is divided between operating specials 5 & 6, and forming the Game On logic (with help from U 56) to enable/disable the special group and flipper relay.
The schematic shows that special 5's driver/pre-driver are tied to the 2-input NOr gate using pins 1, 2 & 3 of U 50. In this case, the pin 3 input is the Game On line, commoned with its five equivalents in the special group, and Low during play and test. The pin 2 input has a connection to the Special Switch connector (not used on this game) and the Cpu's control for special 5, labelled 'E'. A NOr (NOT/Inverse Or) gate should only show a High output with both inputs Low, so here pin 3 should drop Low when a game is started, so that a Low pulse on pin 2/'E' produces a High pulse from pin 1, switching the pre-driver/driver and coil. Other components involved are resistors R 102, 103 & 104, a resistor in the package SR 20, zener diode ZR 7 and capacitor C 75.
To clarify about the redundant Special Switches, when used the contacts closed by the spoon blade (or of the twin rubber band switches, for slingshots) had no concern with the switch matrix - the relevant Special Trigger was pulled to ground with the contacts closed, providing a hopefully brief input pulse for the NOr gate and energising the coil (provided that Game On was also at its valid Low state). The first that the game program knew about this was when the additional matrixed 'Scoring' switch was permitted to close by movement of the bumper armature, or slingshot linkage, producing sound effect, point score and any other programmed action, e.g alternating lit bumper lights.
