Thanks for indexing all of this. A flat text file of all of the entries would be of use also. Do you know if this can be put on line? Someone was asking about it on alt.sys.pdp8 recently DEC-8I-H2CA-D PP8/I High-Speed Paper-Tape Punch Option Functional Description   DEC-8I-H2DA-D PR8/I High-Speed Perforated Tape Reader and Control Option Functional Description   DEC-8I-H8NA-D KT8/I Time-Sharing Option Functional Description   DEC-8I-HOCA-D KE8/I Extended Arithmetic Element   DEC-8I-HODA-D KB8/I General Input/Output Interface Option Description