STRAIGHTFORWARD



                       Uploading Programs
                         From the HP41Cx
                          To the IBM PC
                     Using the HP LINK Card


The link card from Hewlett-Packard is a plug-in card for IBM PCs
or compatibles that adds an HP-IL interface to the computer.  The
software that comes with the card, however, is designed to work 
with the Portable (HP-110) or Portable-Plus lap-top computers.  
There is a way for the HP41Cx to communicate with the PC for the  
purpose of uploading HP-41 programs - however unfriendly.

One of the programs on the LINK Card diskette is called CS80.  
This is the primary communications program.  When you install 
the card and run this program you will be able to use two of the  
three options on the menu:  PRINTER and DISPLAY.  The DRIVE 
option does not work with the HP41Cx.    

The PRINTER option allows you to use the printer on the PC with 
your HP-41Cx, using the PC as a dumb interface.  The  special 
feature of HP printers, such as graphics, will not be available.   

The DISPLAY option allows you to use your PC as a video interface 
(good for conserving printer paper).  Certain special HP 
characters will display incorrectly on the PC.

Because the DRIVE option is not available to the HP41Cx, some 
other way to get the programs into a file is necessary.   What we 
will use is I/O REDIRECTION.  This is a fancy term for DETOUR.  
We will simply route whatever is going to the display into a 
file.  There are two unpleasant side affects to this.   One, 
EVERYTHING goes to the file,  meaning that we will not be able to 
monitor the activity.   The second side affect is garbage is 
introduced into the file.   This is simple enough to fix with any 
standard text editor.   Simply go into the file and remove what
does not belong (note: if you have a time module installed in 
your HP-41Cx, the time and date will also be transferred, remove 
that, too).
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ŠHere are the step-by-step instructions for program transfer.  The 
instructions are for a two drive system.  If you have a hard disk 
then you'll have to slightly modify the steps.

1. Install the Link card as per the Hewlett-Packard instructions.
2. Hook the HP41Cx to the Link card interface.  Do not place 
   anything else on the loop.  
3. Place a diskette with CS80 in drive A and a blank, formatted 
   disk in drive B.
4. At the DOS prompt type: CS80  >B:FILENAME.BTN  <carriage-
   return>.   The file name is unimportant, as long as the 
   extension is BTN.
5. Press the number '3' on the PC keyboard (don't worry that you 
   can't see anything).
6. On the HP-41, type:   PRP "PROGNAME"  (XEQ ALPHA P R P ALPHA 
   ALPHA P R O G N A M E ALPHA)
7. Sit back and wait for the program to transfer.  Every few 
   seconds the disk light on the PC should flash for a moment.  
   When the light stops flashing altogether (nothing for about 15 
   to 30 seconds), the transfer is complete.
8. Press  'E' on the PC.  The file will be closed and you'll be 
   returned to the DOS prompt.
9. Use a standard text editor to clean up the program file.   Do 
   not use a text editor that places formatting characters in 
   files.  If you use Wordstar, use the NON-DOCUMENT mode.
10. You have now transferred a program to the PC.  The next 
   step is to compile the program.


               Compiling Programs From a Text File

1. Run the HP-41 emulator program.  
2. Using the menu command "C", select the correct drive and 
   subdirectory that contains your uncompiled programs.
3. Press the  "!" character ( shift  1).  All uncompiled 
   programs with the extension "BTN" will be displayed.
4. Use the cursor keys to select the desired program and press 
   return.  The program will now be compiled.
5. If the program compiles without error,  you will be placed in 
   the calculator mode.  Press the [F2] key to exit back to the 
   menu.
6. Press "S" to save your compiled program.
7. If you received a SYNTAX ERROR you must exit out of the 
   emulator and investigate the program with a text editor.
8. To toggle back to displaying compiled programs, press "!" a 
   second time.


Things to look for:

XROM ##.##  If you have removed a module, this may be displayed
            instead of the function name.  Replace ALL XROM 
            numbers with the proper function name.

Synthetics  Synthetics are not supported.  If the program 
            contains such statements as STO M, you must rewrite
            the program to remove them.  Synthetic characters
            will usually transfer correctly.  Some characters
            have a different code number and thus display as 
            something else.

Garbage     If the file is not properly cleaned, some text 
            garbage may cause a SYNTAX ERROR.