10, steps A20 and A21).
If a bar 71, or opaque region of coding ring 19 is separating the photo-optic elements, the phototransistor 75 will indicate a "low" (digital zero) electrical state, while a slot 69 interposed between the photo-optic elements will permit light to pass from the LED.
This releases pin 61, enabling stop lever 59 to push pawl arm 31 upwardly and to the left under pressure of stop spring 35, causing pin 33 to lodge between two adjoining teeth 11 of sprocket 9 and stop the rotation of reel.
Serial input and output circuits 109, 111 operate in conjunction with clock pulses from serial clock 93, and latching and enabling pulses from Read/Write Logic 107, to communicate serial input and output information from and to microprocessor 89 on the eight bit databus.The main program then loops for 350 milliseconds at step A9 to allow vinca minor alba plantafstand sufficient time for cocking motor 52 to move camshaft positioning disc 68 off the "home" position provided by finger.Parallel input terminals PI of buffer 145 are connected to eight miscellaneous inputs, such as a phototransistor (not shown) for detecting the open or closed state of door 28, which accesses the interior of machine housing 147.As explained above in the discussion of FIG.At step C31, the contents of temp8, which holds the intended stopping position of Reel 2, are transferred to temp1 for use in the Wait Stop subroutine of step C32.10B) if the microprocessor has counted 28 samples of Reel (0) with no transitions.The first stage of serial input buffer 123 comprises a serial to parallel eight bit shift register which shifts in the data appearing at terminal SI each time a clock pulse CLK is received at terminal.At step D2, the extra transition flag of Reel (N-1) in register xtratr is cleared.These states may be referred to as "non-reel spin states as they involve data processing operations which take place either before or after the spinning of reels 2 in a round of game play.These flags will stay set until the stop solenoids of their corresponding reels have been fired in a later Interrupt routine.When the aggregate number counter again equals zero, the stopping solenoid 65 of reel 2C is energized to stop that reel and complete the round of game play.
The first stage comprises an octal latch which responds to a latching signal at terminal L for latching the data at input terminals PI to the first stage outputs.
If the Reel (0) soft error flag had been set at step C1, this would indicate that soft error processing was still in effect after deenergizing the stopping solenoid 65 of Reel (0 so the real should either be stopped or about to stop.
Microprocessor 89 is programmed to initiate a new Interrupt routine every 250 microseconds, which alternately performs a routine for controlling the spinning and stopping of reels 2 (hereafter "Reel Control Interrupt or a routine for processing serial I/O (hereafter "Serial I/O Interrupt.If the microprocessor determines that the cocking motor is on at step C11, the program proceeds to step C14, at which it loops until all reels have passed their home positions.Thus, register temp2 keeps track of the aggregate number of fields of Reel (N) that have passed its sensor 25 since the start of the Random Count subroutine.During the Reel Monitor routine the main program counts down the generated random number for each reel in conjunction with Interrupt routines that monitor the reel's rotational position, then stops the reel and checks to make sure it has stopped at the intended rotational position.9A to 9D are flow charts illustrating the processing steps performed by the microprocessor of FIG.This initiates a free-wheeling rotation of reel 2 at approximately one revolution per second.Accordingly, the latched data is normally transmitted to output terminals PO, then amplified by driver circuit 151 and transmitted to stopping solenoids 65 and cocking motor.As the left end of first trip lever 49 clears toggle link 47, the toggle link collapses under the pressure of start spring 37, causing guide arm 41 to rapidly pivot counterclockwise about pin 43, drawing pawl arm 31 downwardly and causing pin.

Serial input circuit 109 uses a 24 bit parallel to serial shift register 121 to multiplex twenty-four separate digital input signals for transmission to microprocessor.
If a transition is sensed between any two successive samples of a given phototransistor during the idle mode, control circuit 29 transmits a "tilt" or error signal to indicate that improper reel movement has taken place, and inhibits subsequent game play until the tilt condition.
It will be recalled that xtratr was cleared at step A3 of the main program, in conjunction with the enablement of "soft error" processing.