gonzalez@bbn.com (Jim Gonzalez) (11/16/90)
Now that I have the HSIO (many thanks to those who responded) working, my attention has turned to terminal emulation and file transfer software. Included with the commercial distribution of BDS C is the source for a program called CMODEM. It claims to implement the MODEM7 protocol, which Jay Sage told me is also known as XMODEM. I've successfully compiled and linked CMODEM, and the terminal emulation component seems to work well enough (I'm using it to enter this posting, for example). When I attempt to transfer files from various boards that support nMODEM (where n is X,Y, or Z), I get nothing. I tell the remote host that I want to do an XMODEM transfer, escape to CMODEM's command level and tell it to receive the file. It sits there doing retries, showing no errors or received packets. Aborting the transfer from my end, using ^X, and returning to terminal mode shows that the remote host received the abort signal (a pass-through of the ^X I typed, according to the source) and is waiting for me at command level. Has anyone here successfully built and used CMODEM? Perhaps I'm specifying the wrong protocol to the remote host (Jay indicated that specifying XMODEM *without* batch mode or 1K mode was the way to go; I tried 128 and 1K, CRC and checksum in various combinations). -Jim.