through 136 12 respectively such that a 360 u00b0 rotation of the motor shaft produces two pulses those pulses are input to control electronics which will now be described in conjunction with fig1 through 29 turning first to fig1 17 and 18 two eight bit words are received in the upper left hand corner of fig1 from the control computer 32 the first eight bit word 150 represents the distance a drawer is to travel from the second eight bit word four bits 152 represent a drawer select signal a bit 154 is representative of a start transaction a bit 155 is representative of direction a bit 156 is representative of a u201c clear error u201d signal and a bit 157 is representative of a u201c retry u201d signal the distance bits 150 are input to a counter 158 a comparator 160 is responsive to the counter 158 the comparator 160 is also responsive to a plurality of switches 162 which set a value to which the comparator compares the output of the counter 158 the counter 158 is loaded with the distance information encoded in the bits 150 the counter 158 then begins counting down from the loaded value while the counter is counting down the drawer is being driven at a first high speed when the counter reaches the value set by the switches 162 the comparator 160 produces a signal.