1062 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1953 



Fig. 15 — Trouble recorder card showing the multip 



plugs, cords and jacks. This set can be used for adding and removing 

 cards and verifying that the new card will drop. Bins are provided for 

 storing cards in the process of adding, removing, and transferring cards. 

 Timing tests can be made not only of the over-all time of the translator, 

 as from the trouble recorder frame, but also of the individual component 

 parts of the translator. The test set can also be used for removing the 

 translator selector unit and for bench testing this selector. In this con- 

 nection, a re-cycling test can be made of the code bars, card support 

 bars and latches to check that they operate smoothly and evenly. Cur- 

 rent flow adjustments can be made of the code bar solenoids, latches, 

 and pull up and pull down magnets. 



DESIGN OBJECTIVES 



When, in the course of the development, the controlling require- 

 ments that had to be met became apparent, the design objectives were 

 considered. The reasoning applied is set forth in retrospect in the fol- 

 lowing paragraphs. 



It will be apparent from the foregoing that administrative problems 

 would be involved should it be necessary to arrange and maintain the 

 individual cards in any particular order in the card stack and, therefore, 

 indiscriminate loading became a design objective. 



Since the cards will be changed from day-to-day and sometimes on 



