|Re: 42s rom|
Message #7 Posted by Raymond Del Tondo on 16 Sept 2007, 5:22 p.m.,
in response to message #6 by Miguel Saiz
I think the approach for a rebirth of the 42S would be
similar as with the 33s/35s: A simulation written in C/C++.
But the OS of the 42S is much more powerful and complicated than that of the 33s/35s.
As I wrote in another thread, the original 42S OS consists
of an RPL kernel with a simulated RPN usr interface.
Yes, it's not rocket science, and there is a 42S simulator already,
Free42 in particular, which is available for various platforms,
even my N770 runs a flavour of it.
Regarding the original HP-17BII:
The HP-42S and the original saturn-based HP-17B/II share a similar kernel,
and have a similar RPN-like user interface,
but the 17BII does _not_ have all the functions that the 42S provides,
and vice versa.
However it's perfectly possible that the developer(s) of the 35s
designed the code so that ist may be reusable for s.t. like a new 42S...
...and if it provides a binary compatible FOCAL execution engine,
it will be even better;-)
For those who do not know what I mean with FOCAL execution engine (FXE):
The original HP-41 implements a mechanism to execute binary streams,
and a FOCAL program written on the HP-41 is a series of bytes
which will be fed to that engine.
The two reincarnations of the HP-41 from HP,
the HP-42S and the HP 82210A HP41CV Emulator card for the HP-48SX,
both feature a binary compatible FXE, which means you can feed
the same binary stream to either of the engines.
The emulators, like Emu41 from JF Garnier, V41 from Warren Furlow,
Emu42 from Christoph Giesselink, and the saturn-based emus
from Hrast also implement that compatible FXE, of course,
because each of these emulators uses the original ROMs;-)
Free42 is a bit different, as it doesn't use the original ROM code,
but I think the FXE is similar, at least if it's functionally compatible.
However I haven't checked this particular case.
The HP-71 HP-41 Translator module is a completely different beast.
As the name implies, it translates HP-41 FOCAL streams
into functionally equivalent FORTH words.