HP-41 - PC Gateway & Emulator

by Christoph Klug

Those HP-41 enthusiasts using the HP-IL/PC Interface Card have an excellent device for adapting the handheld computer to the modern PC world. You will find many details about interfacing the HP-41 to a PC in the I/O-Board manual, chapter XV and in Datafile V16N5, V16N6, V18N3, V19N3 and V19N4.

New HP-IL/PC interface hardware now available

There is continuous demand from HP-41 users for the HP-IL/PC Interface Card which is only rarely available second-hand from sources such as eBay. Consequently, I have created a second generation, specially built version of the HP82973 ISA bus card (half-length). Small layout bugs in the first generation, special build version have been fixed and the boards have an absolutely professional design including a solder top mask and gold plated terminals. The ICs are mounted with high quality sockets, and the system includes the hard to find, exotic components IL-Terminal, IL-Transformer and IL-Chip!

Some HP-41 enthusiasts have asked about a HP-IL/PCI bus interface card version, but, for now, the design is the classic 16 bit ISA bus plug in card. Several modern PC motherboards provide one or two ISA bus slots in addition to PCI bus connections while other PCs, like the HP-Vectra, have special ISA bus extension boards, mounted beside the PCI bus motherboard. This is helpful because other specialist measurement cards and interface systems are also not available for the PCI bus. You may be concerned that modern operating systems like WIN2000/NT/XP have addressing limitations with ISA cards but, fortunately, advanced software driver tools exist which can solve these problems.

Unfortunately, the BIOS and firmware of modern PC floppy drives have limitations working with LIF disks created by the HP9114 IL-Disk-Drive. Solving this is only possible by using older PC hardware, for example a nostalgic 286/16MHz PC, and which is also compatible with the unique LINK PLUS transfer software package for HP-41, HP-71 and HP-75 handheld computer.

Altogether the classic ISA bus version is the best compromise and different reasons exist for HP-41 users to install the HP-IL/PC Interface Card in an old PC or in a modern (ISA bus) compatible PC!

HP-41 - PC gateway software

Beyond the basic idea of creating a second generation HP-IL/PC Interface Card, there was a vision of having advanced PC software enabling many more gateway features between the HP-41 and PC worlds. With the original card, users needed to use a combination of software tools such as TRANS41 and additional HP-41 emulator software packages. What is wanted is a powerful "all in one" solution which includes gateway/transfer features plus advanced HP-41 emulator capabilities! Therefore I contacted Jean-Francois Garnier, asking him about producing a new and expanded version of his HP-41 PC emulator software EMU41.

The real HP-41 is much more than a mere calculator, it can also be a system controller using the HP-IL Interface Loop. With this some surprising computer setups are possible including hardware interfacing, measurement and control applications using an I/O-Board or IL2000 System. Jean-Francois is mirroring these system features from the real world in his virtual EMU41 and he is now the first to include HP-IL support in an emulator!

With the new EMU41, the HP-IL/PC Interface Card acts as gateway to the real world. It can control real external IL-Devices, for example reading the HP3468 IL-Digital Multimeter and outputting data to the HP7470 IL-Plotter! Additionally, the new EMU41 can provide and control some virtual IL devices like DISPLAY (video screen), PRINTER (routes data to LPT1 parallel port), FDRIVE1 (working with HP9114 LIF disks), HDRIVE1 (a new mass storage unit) and DOSLINK (for ASCII data transfer to PC world).

Real HP-41 and virtual EMU41

Furthermore Jean-Francois brings both together, the real HP-41 and the virtual EMU41. Connect the "forty one" to the HP-IL/PC Interface Card and switch on the calculator: the handheld scans the Interface Loop and detects the virtual IL-Devices from EMU41. Select the HDRIVE1 mass storage device for easy uploading and downloading of data and programs between the HP-41 and EMU41. Transfer the HDRIVE1.DAT file by email and you get fast and easy exchange of HP-41 data, programs and ROM image-files with other HP-41 enthusiasts. Select the virtual DOSLINK device for uploading ASCII data from real HP-41 to the PC world for post-processing with a spreadsheet, for example.

For advanced data logger applications with the HP-41, you can also transfer non-normalised numbers (NNNs) from the handheld to EMU41. EMU41 decodes the received numbers and stores them to a DOS file for data import to other PC software applications.

Last but not least, EMU41 is truly an advanced HP-41 emulator. By installing ROM image-files, EMU41 can create HP-41 Barcode plots (SKWIDBC ROM plus PRINTER) and gives you real Ram-Box features (MLDL.DAT file plus ZENROM or W&W or ERAMCO operating system).

A nice double pack for HP-41 enthusiasts

The vision has become reality and EMU41 has grown into the necessary "all in one solution" the software tools LINK PLUS or TRANS41 are no longer needed (but also compatible to the new card). The nice hardware/software combination of HP-IL/PC Interface Card and EMU41 gives you useful gateway and advanced emulator features.

Future extensions of EMU41 will following later, for example supporting a second virtual HDRIVE2.

Making this nice double pack available to HP-41 enthusiasts is possible because of the helpful inputs of Emmanuel Compes and Wlodek Mier-Jedrzejowicz (adding some of the exotic IL-Transformers and IL-Chips), Leo Duran (testing an address routing software tool for WIN2000/NT/XP) and the ingenious work of Jean-Francois Garnier (expanding his nice EMU41 with powerful HP-IL features)!

The new EMU41 software will be available by the end of November 2002. For the full version (including HP-IL) Jean-Francois wants a fee of $20. The price for a new, function tested HP-IL/PC Interface Card is $150. Remember, this version is a hand-built edition and not comparable with usual mass marked products. For more information about this powerful HP-41 ? PC gateway solution contact jfgarnier@wanadoo.fr for ordering a personal signed full version of EMU41 or the author christoph.klug@gmx.de for getting the new HP-IL/PC Interface Card including some accessories.

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Page last modified : 24th January 2004