The Rev. B/7/1/71 63-page manual, S/N#139, plus Appendices, prepared by the Iowa City, IA Engineering Department, JVM Mgr., covers the Model W-400/D Mark-Sense (OMR) Reader interfaced to a Model HP-2116B Hewlett-Packard Computer. Appendix A, WLC STANDARD ALPHA MS-GRID Specs, contains 6 pages, Appendix B, SYSTEM REFERENCE MANUAL for W-400/D DIAGNOSTICS, contains 34-pages, and Appendix C, CARD STOCK, INK, and PRINTING SPECIFICATIONS for the W-400D OMR Reader, contains 23 pages. Numerous diagrams, tables, & drawings are also included in this 'groundbreaking product' of its day. An Original Copy is provided