Thanks for making your HP-85 emulator available, I'll try it
this weekend for sure.
I have very, very fond memories of this machine, as I was lent one for a long time, shortly after it was released (come to think of it, even *before* it was released here in Spain). I spent countless nights using and programming it, and wrote a lot of software for it, first in its built-in BASIC language, then creating assorted binary files implementing various utility keywords.
I had the Mass Storage, Matrix, Plotter, and Advanced Programming ROMs, but no Assembler ROM for the machine so I had a tape version of the Assembler, which, if I recall correctly, included an assembler written in BASIC, plus the STORb binary, which included the STOREBIN keyword to write the assembled binary to tape in its proper format. I also remember that all binaries I wrote at the time did include the SCRATCHBIN keyword, so that they could be erased from memory by a running BASIC program in order to load another binary using the LOADBIN keyword, as the HP-85 didn't allow more than one binary program loaded at a time (unlike the HP-86/87, which allowed up to 5) and further, it had no means of erasing from memory the one loaded. SCRATCHBIN would do just this.
I still have some HP-85 materials scattered here and there: several tapes containing assorted programs and binaries (the assembler, many of my binaries, BASIC games, binary games, etc), assembler listings (thermal paper, still not faded !), an original of the Matrix ROM User's Manual, listings of long commercial programs (structures, archicture, engineering), and even a Tutorial Course about the HP-85 I created to be imparted at a local Engineering Association, very nice and with very good examples. In its very last chapter, I did include a short section on binary programs, which featured a short assembler listing which implemented the FACT (factorial) keyword, just to show how you could extend the existing instruction set with ad-hoc, custom keywords. That FACT implementation was pretty simple, but it did run much faster that any BASIC implementation.
One of the most amazing binary programs I saw at the time for the HP-85 was VC, VisiCalc (an early Excel-like program) and as
for games, a friend of mine wrote (and demonstrated) a Chess program, its game engine being totally written in Capricorn's Assembler, plus a small BASIC program for the graphics and the interface. It didn't play very well but was *wonderful* to look at (we're talking late 70s-early 80s here).
Ah, those were the days ! ... 8-)
Best regards from V.