The iBIZ KeySync was a battery-powered keyboard from the year 2000 designed for use with Pocket PC PDAs. I found some at a surplus sale and got one working with a USB-to-RS232 adapter.
make
./keysync /dev/ttyUSB0
# Some of these settings may be unnecessary
stty -F /dev/ttyUSB0 \
9600 cs8 -parenb -cstopb \
raw -echo -crtscts -echok -echoctl -echoke -iexten -hupcl \
intr undef \
quit undef \
erase undef \
kill undef \
eof undef \
start undef \
stop undef \
susp undef \
rprnt undef \
werase undef \
lnext undef \
flush undef
od -tx1 -w1 /dev/ttyUSB0