Computer testing system

Claim 1

IN A DATA HANDLING MACHINE OF THE TYPE WHEREIN EACH WORD IS REPRESENTED BY A PREDETERMINED NUMBER OF BINARY SIGNALS AND A PARTY SIGNAL IS ADDED AS REQUIRED, AND WHEREIN SAID WORDS AND SIGNALS ARE READ FROM A STORAGE SYSTEM IN WHICH THEY MAY BE STORED BY A READING CIRCUIT AND ARE THEN CONTINUED WITH CLOCK PULSE SIGNALS FOR REGENERATING THE WORD AND PARITY BIT SIGNALS, MEANS FOR DETECTING DETERIORATION IN SAID READING CIRCUIT COMPRISING A BISTABLE STATE FLIP-FLOP CIRCUIT, MEANS FOR APPLYING EACH SAID REGENERATED WORK AND PARIT SIGNAL TO SAID FLIPFLOP CIRCUIT TO DRIVE IT FROM ONE TO THE OTHER OF ITS STATES OF STABILITY IN RESPONSE TO EACH "ONE" REPRESENTATIVE SIGNAL CONTAINED THEREIN, A PHASE-SHIFT CIRCUIT, MEANS FOR APPLYING SAID CLOCK PULSE SIGNALS TO SAID PHASE-SHIFT CIRCUIT PRIOR TO BEING COMBINED WITH THE SIGNALS READ FROM SAID STORAGE SYSTEM, MEANS FOR ACTUATING SAID PHASE-SHIFT CIRCUIT FOR ADVANCING THE PHASE OF SAID CLOCK PULSES RELATIVE TO A REFERENCE POSITION A PREDETERMINED AMOUNT AND FOR RETARDING THE PHASE OF SAID CLOCK PULSES RELATIVE TO A REFERENCE POSITION A PREDETERMINED AMOUNT, A CYCLIC COUNTER HAVING A CAPACITY EQUAL TO THE NUMBER OF BINARY SIGNALS IN A WORD PLUS A PARIT SIGNAL, MEANS FOR APPLYING CLOCK PULSES TO SAID COUNTER FOR CAUSING IT TO BE DRIVEN, MEANS TO DERIVE AN OUTPUT FROM SAID COUNTER WHEN IT ATTAINS ITS LAST COUNT STATE, GATE MEANS TO WHICH BOTH SAID COUNTER OUTPUT AND THE OUTPUT OF SAID FLIP-FLOP WHEN IN ONE OF ITS BISTABLE STATES IS APPLIED TO PROVIDE AN OUTPUT IN THE SIMULTANEOUS PRESENCE OF BOTH INPUTS, AND AN INDICTOR TO WHICH THE OUTPUT OF SAID GATE MEANS AND SAID COUNTER IS APPLIED TO BE ACTUATED WHEN IT RECEIVES ONLY ONE OF ITS TWO OUTPUTS PROVIDING AN INDICATION THAT THE READING CIRCUIT IS DETERIORATING.