TECHNICAL NOTES - Improvements and Additions — February 1982 - Functional Test and Calibration - Operation of Cassette Inter-face - Operation of Sync—To—Tape Circuit - Computer Interface Description - DSX Software History - February 1982 - DSX Connectors - Parts List SCHEMATICS - Processor Board (3 Sheets) - Early Sync. Circuit - Swi tch Board - Rear Panel - External Keyboard PARTS LAYOUT DIAGRAMS — Processor Board - Swi tch Board PRINTED CIRCUIT COMPOSITE DIAGRAMS - Processor Board - Swi tch Board ENGINEERING CHANGE ORDERS CECO’s) - ECO #201 - ECO # 202 - EOC # 203 CORRECTION NOTICE (Business Reply Letter)