Date: Sat, 30 Jan 93 15:13:48 PST
From: cokin@scf.usc.edu (Darren Cokin)
Subject: HP48-to-Mac_cable_pins.txt

Below is a document which shows the correct pin connections necessary to
construct a cable to connect HP48 calculators to Macs.  It is much cheaper
to make your own than to pay the $30+ that they go for retail.  Once you
have the wire you can download software to the HP48 with any kermit program.
There is much software for the HP48 available at seq.uncwil.edu, and
hpcvbbs.cv.hp.com.  These include math programs, utilities, games, universal
remote programs, etc.


						     Darren

 -----------------------------------------------------------------------
	   PIN CONNECTIONS FOR HP48 TO MACINTOSH CABLE

	       By Darren Cokin (cokin@scf.usc.edu)


Here are the pin connections necessary to make a cable from your HP48 to
your Mac.  You're on your own finding connectors to fit the jacks, but
at least now you know which wires to solder together.  Just match the
numbers.


Looking at back of HP48

    ---------
   | 1 2 3 4 |
    \_______/


Looking at back of Mac serial port (modem/printer port).
This type of connector is called a "9-pin Mini-DIN" (the 9th
pin is the outer ring).  X marks pins that are not used.

     -------
   (         )
 (  X   X   X  )
(               )---1 (outer ring)
(  2     4   3  )
 (             )
  (   X   X   )
    ---------


This has been tested to be the same configuration as the cables that
are being sold, but I make to guarantees.  Use at your own risk.  I
take no responsibility if you damage either your mac or your HP48.
Feel free to distribute this document, I place it in the public domain.

						       Darren Cokin
						       1/29/93