HP-41 <> USB-41 bidirectional comms.

[Diego Diaz]

Hi all,

If you have a USB-41 interface module, this may be an interesting reading... if you don't have the USB-41 (yet), it may be interesting for you... to get one! :-)

As the title says, I've managed to develop the (too long awaited) bidirectional communication interface between the HP-41 and USB port using the USB-41 interface module.

Note that this is still preliminary and therefore by downloading (here) you're in Beta-tester mode.

In short it allows sending .ROM files from/to your PC and your HP-41 HEPAX RAM pages using HEPAX's COPYROM command, so it does not use a page itself. Also, since HEPAX allows saving *everything* including FOCAL programs and registers into its HEPAX RAM, this virtually means that you can move everything from ROM pacs to your own FOCAL or M-Code programs to your PC and get them back to your HP-41 at will.

Below the notes included in the down-loadable archive:

--- Notes on the USB-41 page transfer utility ---

*********** PRELIMIRARY ***********

Download link: http://www.clonix41.org/Projects/USB-41/USB-41-3.rar

This .rar archive contents the files required to test your USB-41 interface module page
trasfer functionality. Download and extract to your working directory.

Since the aim of this utility is to copy .ROM pages between your PC and your HP-41, some
device with RAM memory is required to be installed into your HP-41 in order to operate.
The HEPAX module or any NoV module running HEPAX can be used.

The HP-41CL running HEPAX is suppossed to work but I haven't yet been able to test this
configuration for now. Please report if you manage to test such CL configuration.

NOTE: This utility will only RUN at 1x clock rate.

The COPYROM command is used to handle the transfer process either from HP-41 to PC or
from PC to HP-41. For this purpose the File in your computer is to be considered as page
number #7.

NOTE: Actually for the HP-41 to PC transfer it is not relevant, since any page transfer will
be copied into the specified .ROM file. For PC to HP-41 it is mandatory that the source page
is #7.

The USB-41-3.exe file will run in your computer under windows; it has been tested on
Win 7 32 & 64 bits versions. Please report if you test it on other windows platform.

The two .OCX (ActiveX) controls included are required for the program to run just in case
you don't have them already installed. They can be kept in the working directory.

The ClonixU3.HEX file is the code to be programmed into your USB-41 interface module.

Run microbrn.exe, and select "Load file" to program your USB-41 as usual.

Once it is programmed connect it to your HP-41 calculator, connect the USB port
end of the cable to a suitable port of your PC, turn your calculator ON and run
USB-41-3.exe in your computer.

Make sure your COM port is shown in the Port selection field. Check windows device manager
if necessary to confirm the port number assigned to your COM port.

Note that this utility only manages COM1 to COM9 serial ports. You can change the COM port
number in the device manager if required.

Hit the Refresh button, in case you have added a new port, in order to let it show up in the
Port selection field.

Click on the File selection filed to choose either an existing .ROM file or to name a new
.ROM file.

In your HP-41 enter the required info for the COPYROM command:
- source page number into Y register
- destination page number into X register
NOTE: It is convenient to have the COPYROM command Assigned to a key in order to facilitate
its execution.

To send a page to your HP-41:

Click on "Send page" in your PC window, then key [7] [ENTER] [nn] [COPYROM] in the HP-41.
[nn] is the RAM page number where you want the .ROM image to be copied to.
[COPYROM] is either typed in ([XEQ] [ALPHA] COPYROM [ALPHA]) or (preferrable) assigned key.

To Receive a page from your HP-41:

Click on "Receive page" in your PC window, then key [nn] [ENTER] [7] [COPYROM] in the HP-41.
[nn] is the RAM page number you want to be sent to the selected .ROM file.
[COPYROM] is either typed in ([XEQ] [ALPHA] COPYROM [ALPHA]) or (preferable) assigned key.

Please mail me or post any comment, hint, problem... praise... :-) you may have.

All the best from Caribbean Sea.

Diego.

PS: Screenshot of the very simple GUI, some of you will be happy to know that this is just VB6. I'm planning to get rid of the .NET as soon as I can.