For a pair of 49Gs, connect the calculators using the 10-pin to
10-pin cable. Make sure that the reserved variable IOPAR matches
in the calculators (and makes sense). Flag -33 should be clear in
both calculators (Transfer via wire). You could tranfer using
either the Xmodem file transfer protocol or the Kermit file
transfer protocol. For Xmodem, you could use XSEND on one and
XRECV on the other, or you could put one into Xmodem server mode
and use XPUT and XGET on the other. For Kermit, binary transfers
are faster than "ASCII" transfers, so set flag -35; you could use
SEND on one and RECV on the other, or put one into server mode and
use SEND, KGET, and FINISH on the other.
Starting with the 49G, XON/XOFF software flow control no longer
works, so the "serial I/O" commands (XMIT, SRECV, and so on), may
cause a receive buffer overrun if you send more than 255 bytes at
a time.
Perhaps easiest is to press APPS, select I/O functions, and then
use the obvious options in the choose boxes and input forms.
For the 49g+, transferring between two calculators "via wire" is
impossible because you'd need one of them to be a "USB host" and
the other to be a "USB device", and the 49g+ is a "USB device"
only. For transfers between a pair of 49g+es, use IrDA, that is,
set flag -33, line up the IR arrows and have the calculators
within an inch or so, and otherwise proceed as with a pair of 49Gs
communicating via wire.
For transfers between a 49G and a 49g+, a direct connection isn't
possible; you have to use something else (such as a PC) between
them. Note that you can open two instances of Conn4x with one
connected with the 49G and the other connected with the 49g+, and
"drag and drop" (or copy and paste) between them.
The 50g plus has IrDA, USB, and serial ports, so a 50g can
communicate with another 50g or a 49g+ via IrDA. The 50g (in
"Transfer via wire" mode) uses flag -78 to select between using
USB and serial, but I don't, offhand, know which state is USB and
which is serial. If you could get the right cable (input and
output lines reversed and no connection on the battery+ line), you
should be able to connect a pair of 50gs via their serial ports.
Note that the 50g's serial port is not RS-232 compatible, so to
use it to communicate with a 49G (or any other RS-232 compatible
port), you'd have to use level-shifting hardware between them.
Also note that the IrDA on the 49g+ and 50g is not compatible with
the IR transfer signal used with the 48 series.
The 48G series doesn't have the Xmodem server built-in, but the
Conn4x package includes an Xmodem server library for the 48G
series.
The 48SX/S doesn't have Xmodem built-in, but you could try a
search of hpcalc.org for Xmodem for the 48SX/S; it might be
available for all I know.
The 49g+ and 50g can print via IR to the HP82240A/B printer, but
the range is greatly reduced from what it is with the 48 series.
Regards,
James