Automated Digital Switching communications programmers · Merged into 491X2, date not stated by source
Local OCR renders 511X1 as “51 TXT”; code is recorded from the printed AFSC pattern, and D-prefix patterns are preserved.
Sources
- Communications-Computer Systems Operations and Programming, AFSC 491X1/ X2 (Internet Archive full-text OCR lines 324-359; adjudicated excerpt in audit)