Ha ha guess what! Turns out I HAVE the OPT 001 Operators manual as well. Background: I bought a very beat-up 1640B (no HP-IB option) early last year. Started to work on it while also hunting the manuals. Got stuck needing some parts I didn't have. Put the unit aside, disassembled in a box, till those could be found. Then had major life distractions, including a trip to the USA late last year, and some illness this year. This thread reminded me, I should resume that restoration. Found the manuals, which I store in big ziplock bags. One has the 'user manuals' which for the 1640B are small-format black-covered booklets. Several copies, since they tend to get included with service manauls and such.
I just now thought to check in that bag. And I do have the OPT 001 Operator's guide after all. Will try to scan it asap. A bit more difficult, as it's staple-bound, and uses color screening.
