(75C) LORAN-C Triplets - position determination

[rprosperi]

(08-18-2019 02:09 PM)SlideRule Wrote:  An extract from Position Determination with LORAN-C Triplets Using the Hewlett-Packard HP-75C, … Naval Postgraduate School, NPS55-83-023, SEP 1983, 41 pgs.

"ABSTRACT
This report contains user instructions and program listings for a Loran-C position determination algorithm for use on an Hewlett-Packard HP-75C …
…
II. THE HEWLETT-PACKARD HP-75C.
HP-75C USER INSTRUCTIONS.
The options are labeled 1 through 9, A or H. The H (Help) option will review options 1 - 9 & A. Option 6 (TWO POINT HEAD & DIST) is a stand-alone option which may be used by itself. For LORAN fixing, Option 8 must be selected first to load the station GRl's. If Option 8 is not used, then any option requiring the GRI's will automatically enter Option 8 first. Option 1 (LORAN FIX) must be selected at least once before Option 2 (ALTERNATE SOLN) can be selected. Once the GRI's are loaded, any of the remaining options may be used at any time. When first run, the ASF Correction Factors are set to zero; if they are subsequently entered as non-zero values they will remain set until either changed manually, by selection of Option 9, or until the program is RUN once more. In all cases, South latitudes and East longitudes must be negative for input and will be labeled by a minus sign '-' on output. For ease of reference the options are listed by number rather than by sequence of selection."

A basis for the HP-71?

BEST!
SlideRule

Nice! A rare treat, finding a 75C program with ample docs like this, thanks for digging this up and sharing here SlideRule. A shame the 75C listing was done on the narrow 82162A printer, so it's hard to assess the coding without relatively painstaking review (scrunched-eye closeup reading the listing) but it should be interesting. Stashed away for a rainy day (in 2020).

Thanks!