Any Kermit-based application that works with your operating system
and can use the ("virtual"?) COM port should work with any 48 or
49 series, except the 49g+. They all have both Kermit and Kermit
Server built-in, although a rather basic version of them.
With the 49g+, you'd also have to convert to IrDA or USB. I've
used the 49g+ with HyperTerminal and an RS-232/IrDA converter
(with Win98SE supplying a virtual COM port), but haven't been able
to get Conn4x to work with IrDA. Conn4x works with the 49g+'s USB,
and I believe that applications for Apple and Linux operating
systems are also available.
The 49 series (including the 48gII) has the Xmodem Server
built-in. As far as I know, this Xmodem Server is unique to these
HP calculators.
The 48G/GX/G+ has Xmodem built-in, but doesn't have Xmodem Server
built-in, although an Xmodem Server library is available. For any
application that expects an Xmodem Server, install the library.
The 48S/SX doesn't have Xmodem built-in, so to use an Xmodem-based
application with it, you'd have to find (or develop) an Xmodem
application, and in some cases, an Xmodem Server. Xmodem for the
48S/SX might be availabe at hpcalc.org.
All 48 and 49 series also have "Serial I/O" commands built-in, so
you could always develop your own communications protocol,
although for file transfers, that seems to me much like
re-inventing the wheel. But note that the XON/XOFF software flow
control capability was intentionally removed from the 49 series,
so you'd have to be careful not to overrun the 255-byte input
buffer. You might want to provide for error checking.
Working in assembly language, you can ignore the RPL input buffer
and build a string in temporary memory, and then replace its bytes
one at a time, as long as your routine is fast enough to check the
UART again by the time the next byte arrives. Again, you might
want to provide for error checking.
Besides HyperTerminal, HPComm, the Kermit-based "Connectivity Kit"
for the 49G, works with any 48 or 49 series. See
http://www.hpcalc.org/details.php?id=3713.
To use Conn4x, the Xmodem-based "Connectivity Kit" for the 49g+,
on a 48G/GX/G+, you'll have to install the Xmodem Server Library
(included with Conn4x) on the calculator. This library doesn't
work with the 48S/SX, although I suppose that one that does could
be developed. Be sure to use only the most recent version (Version
2.2 Build 2353, as far as I know) of Conn4x, available at
HP's site.
Regards,
James