Acronyms and abbreviations

AD F arranged with data features ADS announcement distribution system A L U arithmetic logic unit APUF autonomous peripheral unit failure ASW all seems well AWG American Wire Gauge AUTOVON automatic voice network BLM base level maintenance BOOTCNTL bootstrap control program BSRF Bell System reference frequency CAMA centralized automatic message accounting CAROT centralized automatic reporting on trunks CC control clock CCIS common channel interoffice signaling CCITT International Telegraph and Telephone Consultative Committee (Comitι Consultatif International Tιlι­ graphique et Tιlιphonique) CESR controller error source register CI control interface CLF clear forward CMOS complementary MOS CMP complete CMS circuit maintenance system CPU central processing unit CR call register DCON diagnostic control DDD direct distance dialing DDI direct data insert DIC digital interface controller DIF digital interface DIFRINTR digital interface frame interrupt recovery package DIPs dual in-line packages DIU digital interface unit DMA direct memory access DP dial pulse DT digroup terminal DTCRs dedicated time-slot interchange connection registers ECL emitter-coupled logic EIA Electronic Industries Association EIB extended internal buses ENSIG enable signaling