HP-28S questions

[Christoph Giesselink]

(07-28-2014 02:10 PM)x34 Wrote:  3. How do you enter different characters, eg ":" or ";" not using CHR?

There's no way to enter these characters on the HP-28 keyboard directly.

(07-28-2014 02:10 PM)x34 Wrote:  4. Is there any (semi)OFFICIAL SYSEVAL list fo HP-28S with docs?

There's no entry point list for the 28S from HP. JFG made one end 1996 with ~770 entries. I picked up this list and expanded it to ~2600 entries, but there are still many entries missing, especially the UI ones which implementations are different to the HP-48SX. This list is available here. This list can also be used to create a symbolic entry table for the Emu42 code debugger and RPL object viever.

(07-28-2014 02:10 PM)x34 Wrote:  6. I have user manual, reference guide and all hpmuseum DVDs, but found no info on HP-28 sysrpl programming. Where to search?

There was not much sysrpl programming for the HP-28 end of the 80'ies, because it was quite annoying to enter sysrpl programs into a real HP-28. I don't know what people like Joe Horn have known about the internals of these calculators at this time, but when you have had a look a comp.sys.hp28 the community don't know too much (but we have to respect that they hadn't the possibilties we now have with Emu42). I got my knowledge from disassembling the HP-28S ROM inside Emu42 and compare the disassembly with HP-48SX routines. The reference for sysrpl programming is still RPLMAN.DOC from the HPTOOLS package inside HP 48 Goodies Disk, Vol. 4, but you should use a more recent assembler/compiler like HP Tools for Win32.