This set of documents is miscellaneous software topics. They were orginally with G-15D serial number 186 in Houston, Texas. It is a complete miscellany.
progref1.gif and progref2.gif are two sheets that are a general programmers' reference guide. A lot of machines had information like this in the format of handy little reference cards, but I never saw one of those for the G-15.
Scanned by Mark Linimon, firstname.lastname@example.org, 1/11/2000.