(71B) FORTH questions

[brouhaha]

(07-03-2024 09:31 AM)floppy Wrote:  Has anybody some hint where to find float functions written in ASM? (outside the HP OS/ROM SW listings)

It seems unlikely that there are any floating point routines for Saturn (or the earlier HP calculator architectures) other than the ones built into the machine. There was no advantage to rolling your own, and huge advantage to using what was provided. Even third-party ROMs for the 41 called the 41 mainframe ROMs to do floating point. The 71 was the first machine in the HP APD and CVD development line for which the floating point routines were actually officially documented and supported by HP. The detailed documentation is in the 71B Software IDS Volume II, and the source code in Volume III.

The HP-71 FORTH/Assembler ROM provides floating point words, documented on pages 19-21 of the FORTH/Assembler ROM Owner's Manual. These of course use the mainframe floating point rotuines.

All later HP calculators based on Saturn processors (or Saturn emulated on ARM) used floating point routines derived from the HP-71, but some of the IEEE support was deemed unnecessary and removed.

All HP calculators based on the Nut architecture (41C/CV/CX, 10C-12C, 15C, 16C) used floating point routines nearly identical to the prior 30 series, which themselves are not too different than the 19C/29C/67/97 routines.