Cannon 19 pin data connector. SK19-21C-1/2. SK19-32SL. PGK.pdf from http://www.peigenesis.com/images/products/pdf/FullSpec%20PGK.pdf order for over $125 from http://www.peigenesis.com/ references courtesy of Tom Mikulic http://tomislavmikulic.com/proj-565.html In PGK catalog; following steps, 1) number of contacts suggesst SK-19, #16 wires 2) shell style is 32SL for receptacle on plotter shell style would be 21C for mating cable straight plug 3) cable clamp would be 1/2, 5/8, or 3/4 for cable 4) rotation would be N (no rotation) both connectors 5) shell plating omitted 6) part numbers become: -- on plotter SK19-32SL -- on cable SK19-21C-1/2 (or 5/8 or 3/4) SK19 couping diameter is 1-5/16' coresponding plug is K-21C, coupling nut diameter is 1-15/32 looks like plotter has K-32SL large flange connector if so spacing between screws is 1.280 height of threaded section is 7/16" thread is 1-5/16-6 pins are numbered right to left (3 2 1) top to bottom 3 2 1 7 6 5 4 12 11 10 9 8 16 15 14 13 19 18 17 my rough measurements Screws are 1.3" apart diameter of threaded section is 1.25 inches very roughly inside diameter is 1-1/8 pin are about .060 to .062 (under .0625 or 1/16 tubing) pin spacing .2 inch Mikulic rough measurements (may 10 2010) are pin 1.60 mm (.063 inch) inner diameter 28.67 (1.129 inch) outer diameter 32.41 (1.276 inch) mounting holes 33.20mm (1.307 inch) pin lengths 10.14 (.4 inch) shell depth 11.31 (.445 inch))