Here's a brief summary:
  Put the HP-48 in Kermit server mode.  Set up the Kermit client like this:
  For file transfer, use binary mode unless you are exporting or importing
HP-48 objects:  To transfer files:  To change directory on the HP-48:  To shut down the HP-48 Kermit server:  If file transfers fail, try:  CLICK HERE for
further information.
   
40 How to Transfer Files with the HP-48?
  SET PREFIXING ALL       ; (C-Kermit or Kermit 95)
  SET MODEM TYPE DIRECT   ; (C-Kermit or Kermit 95)
  SET PORT COM1           ; (Or other communication port)
  SET SPEED 9600          ; (Serial port speed)
  SET CARRIER-WATCH OFF   ; (Don't require carrier)
  SET FLOW NONE           ; (Don't use flow control)
  SET PARITY NONE         ; (8 data bits, no parity)
  SET BLOCK 3             ; (if desired, or 2)
  SET CONTROL PREFIX ALL  ; (Necessary in Kermit 95)
  SET FILE TYPE BINARY
  SEND filename           ; Send file(s) to the HP-48
  GET filename            ; Get file(s) from the HP-48
  REMOTE HOST { relative_directory_name } EVAL
  FINISH
  SET SEND TIMEOUT 20     ; (Or other number of seconds)
  SET SEND PAUSE 100      ; (Or other number of milliseconds)
 Kermit FAQ / Columbia University / kermit@columbia.edu