Transferring programs between an HP41 and a PC using a serial interface
----------------------------------------------------------------------

This document describes how to use the HP82164 HPIL-RS232 interface to 
connect an HP41 calculator (fitted with the HP82160 HPIL interface and 
the Extended I/O module) to a Linux PC, and to transfer programs in both 
directions between them.

Throughout this document, the PC's serial port will be named /dev/cua0 . 
Change this as appropriate, of course.

Hardware connections : 
----------------------
Connect the HPIL side of the HP82164 to the HP41's IL module in the usual 
way. 

The jumper plug inside the HP82164 interface should be set to the DTE 
position. See the interface's user manaul for more details of this.

Connect the HP82164's RS232 port to the PC using a standard PC modem 
cable and a special adapter. The latter is needed owing to the rather 
strange hardware handshaking of the HP82164, and the following diagram 
gives the necessary wiring : 

   PC                         HP82164
   (DB25-S)                   (DB25-S)

Prot Gnd 1 )-------------------( 1 Prot Gnd
 
 TxD     2 )-------------------( 3 RxD

 RxD     3 )-------------------( 2 TxD

 RTS     4 )-------------------( 5 CTS

 CTS     5 )-------------------( 20 DTR

 DSR     6 )--+----------------( 4 RTS
              |
 CD      8 )--+

 Sig Gnd 7 )-------------------( 7 Sig Gnd

 DTR    20 )----------------+--( 6 DSR
                            |
                            +--( 8 CD


Configuring the interfaces
---------------------------

On the PC, turn off buffering and enable hardware handshaking by typing :

stty raw crtscts </dev/cua0

On the HP41, load the SETRS program and run it to set the HP82164 
interface to hardware handshake mode and to make it the primary device. 
A binary file of this program is given in hardware/setrs.p41 in the 
lif_utils distribution, and is given as a listing below : 

0001  LBL "SETRS"
0002  66
0003  FINDAID
0004  SELECT
0005  CF 17
0006  REMOTE
0007  "SL2"
0008  OUTA
0009  "LI5"
0010  OUTA
0011  "C0"
0012  OUTA
0013  NOTREM
0014  END

Transferring a program from the HP41 to the PC
---------------------------------------------

On the PC type : 
---------

inp41 < /dev/cua0 >program_file

where program_file is the filename that you want the binary program 
stored in. Alternatively you can pipe the output of inp41 to prog41 to get 
a text listing by typing : 

inp41 < /dev/cua0 | prog41


On the HP41
-----------
Put the name of the program to send (or more exactly one of the global 
labels in that program) in the alpha register.

Then execute : OUTP

When the program has transfered, the PC should display 

checksum good

and the program will be stored in the specified file


Transferring a program from the PC to the HP41
---------------------------------------------

On the PC type :
---------

outp41 < program_file >/dev/cua0

where program_file is the name of a file containing an HP41 program.

The input to outp41 can be piped from lifget (for example) in the 
standard way to transfer a file from a lif disk image. For example :

lifget  disk1 PROG | outp41 > /dev/cua0

will transfer the file PROG from the lif disk image disk1.

On the HP41 
-----------

GTO .. to pack program memory and create a dummy program at the END.

then execute : INP

When the program has transfered, the X-register display will return. CAT 
1 to check that the program has loaded.


----------------------------------------------
A. R. Duell, 2-Oct-2000. 
This file is part of the LIF Utilities distribution and has been placed
under the GNU Public License version 2.0