Re: before I reinvent the wheel Doh! I should have said I was planning on using IR, but a serial cable makes more sense (at least to start with)... Thanks, Paul Adam Oliver wrote in message <001401bf04c9$2bdb6780$1764648c@adam>... I haven't actually done this, but I'm pretty sure the theory is ok... On the handyboard web page is the pa79600 icb file which lets you use port a bit 7 as serial i/o. I have successfully used this to control some minissc's. I think that if you wired a cable between the hp and the Hb (heh heh) you should be able to write some code to display a character sent. In fact I think a few hp pages have a basic serial program on them which you may be able to use... hope this helps, Adam   ----- Original Message -----   From: Dito, Paul   To: 'handyboard@media.mit.edu'   Sent: Wednesday, September 22, 1999 6:48 AM   Subject: before I reinvent the wheel   Has anyone used their HP48 to talk to a handyboard?