Glossary

ABL ABR ACK ADS ALV ALW AMA ASCII ASW AU ATG AUB BOL BOR BPI BRB BWB CC CDI CF CPD CS CSB DGN DMA DR DTTL DUB DUS EIA EMI EX FIT FS FTF Auxiliary buffer order word register left Auxiliary buffer order word register right Acknowledge lamp Auxiliary Data System Adder and logic unit Allow Automatic message accounting American Standard Code for Information Interchange All seems well Auxiliary unit Automatic test generation Auxiliary unit bus Buffer order word register left Buffer order word register right Bits per inch Buffer read bus Buffer write bus Central control Collector diffusion isolation structure Control flip-flops Central pulse distributor Call store Call store bus Diagnose Direct memory access Disk request Diode-modified transistor-transistor logic Data unit bus Data unit selector Electronic Industries Association Electromagnetic interference Exercise mode One failure in 109 component operating hours File store First test failure 313 HIC HWR 10 ITS IOUC IOUS LAMP LSL MADES MB MCC MON MS NVOP OS OW PA PC PCDF PMT PRR PS PPI PS PSB PSL PSR PU RAM REC RMV RO ROS RST RTL SBC SCR SD SIC SR SWAP TF 314 Hybrid integrated circuit Halfword register Input/output unit Installation test system Input/output unit controller Input/output unit selector Logic analyzer for maintenance planning Logic simulation language Machine-aided design system Masked bus Master control console Monitor Monitor store Name match and valid operation Out of service Order word register Pattern analysis Processor configuration Power conversion and distribution frame Permanent magnet twistor Polling request register Program store Processor-peripheral interface Program store Program store bus Program store left Program store right Peripheral unit Random access memory Recovery gate Remove Read only Requested out of service Restore Resistor-transistor logic Standard, junction-isolated, buried collector Silicon-controlled rectifier Scan and signal distributor Silicon integrated circuit System reinitialization Switching assembly program T a p e frames THE BELL SYSTEM TECHNICAL JOURNAL, FEBRUARY 1977 TLP TUC UB UC UTC VREF Trouble location procedure T a p e unit controller Unmasked bus Utility computer Utility test console Reference voltage GLOSSARY 315