Colin Cantwell, the creative mastermind behind many well-known science fiction movies such as 2001 A Space Odyssey and Star Wars passend away on May 21, 2022. He took a consulting role in the development of the 9845C color graphical system and created the at the time mindblowing 9845C demo visualizing what was possible with the right hardware in the early 80s. He also was deeply involved in the making of the War Games movie, where he designed a sopisticated production setup for the impressive NORAD set, where the 9845C played an important role. Colin has been an exceptional specialist, who was driven by his enthusiasm for technical innovation and science fiction. With his talent for connecting technology and art, he contributed heavily to the progress of computer science. By all this, Colin kept being the probably most modest man on earth. See for his web site.


New project, new emulation: If you are already using HPDir and HPDrive, you now can expend your set of emulated HPIB peripherals by a HPIB printer. Currently, four HPIB printer models are supported:

HP2631G impact graphics printer
HP9876A thermal graphics printer
HP2225A inkjet printer (PCL 1.0)
HP82905B dot matrix printer

All output can be either printed on the console output or saved into a file for further processing such as rendering and printing on your local printer. You may use HPPrint with all GPIB boards already supported by HPDir or HPDrive.



Yes, I am on the VCFB in Berlin this year again! Please meet with me on October 7+8 2017 at the Technical Museum in Berlin. And there at least are two exhibitions which might be of interest for you. One exhibition is on the "1977 Trinity" with Apple II, Commodore PET and TRS-80, but even more excisting, I have luckily acquired from Colin Cantwell some of the original HP equipment once used for producing the NORAD graphics in the 1983 WarGames movie (look here for the background). So I will try to re-create the original setup with a 9845C as the hidden star to show how the graphics once have been produced. See this link for more information on the VCFB:

New release candidates of HPDir and HPDrive available for download. Most significant change: We have Linux support now! Had been a big change, since the whole code base needed to be changed and made OS independent. Here are all changes in detail.

Changes from HPDir 2.03 to HPDir 3.0 RC1:

- Linux port (no support for floppies on Linux yet)
- Read-only support for SDF, includes general support for hierarchical file systems w/ subdirectories
- Detection of HFS (although not yet supported for file access)
- Support for HPBasic/HTBasic and HP calculator file headers
- 32-bit and 64-bit plugins for Total Commander, with updated plugin installer
- Support for AMIGO magtapes (7970 etc.)
- Support for the conversion of PASCAL text files
- Extended intgegrated diagnostics
- Some more calculator types for LIF
- Additional user-defined types can be added in hpdir.ini
- Using a 9895A floppy drive to format 9885 floppy disks including 9825 boot track on a 9895A (also works on images)
- Support for new TNT4882/TNT5004 driver >= 3.2
- New config file parser, config file entries now extend/update existing database
- Support for custom PortIO driver added
- Legacy 7210 & NI ASICs drivers merged into a single driver
- 0 file length directory listing/extract fixed
- SIMH magtape image file format support added (for -dup only), includes proper handling of file marks for CS/80 tape drives
- Support for PASCAL filename type encoding in LIF files
- Support for adding multiple files in one single command
- Added check for directory overflow
- Specification of range (from block), allowing to duplicate/recover selected media areas without the need to re-read the full medium
- Support for fast scheduling under Windows 2000 and later (reduces latencies)
- Support for blockwise recovery on read errors
- Many bug fixes & minor enhancements

Changes from HPDrive 4.0 beta 7 to 4.0 RC1:

- Linux port (full ISA support, PCI support experimental)
- Support for new custom TNT4882/TNT5004 driver (version 3.2 and up)
- Several bug fixes

Here it is, THE HP 9845 EMULATOR. F. Ulivi did a fantastic job, he gave us an brilliant and absolutely accurate implementation of a 9845B and 9845C, based on the MAME emulation framework. Also, the 9845B Model 200 graphics option is supported. Check it out! More >...

Some time has passed since the last news. Many others things happening out of the scope of this site. Now here is the latest news: A specially hardened version of the HP9845B appeared on eBay, which has been unknown until now. Obviously modified for use by the U.S. goverment in security sensitive areas. More >...

Linux port of HPDrive and HPDir almost done. The port had been a real challenge but now goes into the testing phase. I will give another note when the Beta version is available for download.

"Internal" information about HP's Nano Processor published. Again many thanks to Larry Bower and Paul Berger for providing the Nano Processor's User's Guide! More >...

New 9835 option ROMs available. Many thanks to Paul Berger for doing the dump and Jon Johnson for providing his collection! More >...



After the success of the first Vintage Computing Festival Berlin (VCFB) last year there will be the next show on October 3+4 2015. And of course, we again will participate in that event. So, if you ever wanted to see those 9845 systems LIVE, this is the chance! Even beyond the 9845, the VCFB is worth visiting with lots of exhibitions, lectures and fun. The VCFB takes place at the Humboldt University in the very center of Berlin. See this link for more information (German only) on the VCFB: Again, I will try to also show a 9845C in action (well at least if not anything is going wrong with that fragile hardware), plus as much equipment around the 9845 series as possible. If you like you are also welcome to listen to my presentation on workstation history in general.

FAQ section on HPDrive added. More >...



Again we are proud to announce that the HP 9845 can be seen on the 2014 Vintage Computing Festival Berlin (VCFB), this time in BERLIN, my home city. The VCFB takes place on October 4-5, 2014, at the Humboldt University in Berlin. See this link for more information (German only) on the VCFB: I will try to also show a 9845C in action (well at least if not anything is going wrong with that fragile hardware), plus as much equipment around the 9845 series as possible. See you in Berlin!


We're proud to announce that the HP 9845 can be seen in action on the 2014 Vintage Computing Festival East 9.1 (VCF). The VCF takes place on April 4-6, 2014, at the InfoAge Science Center in Wall, New Jersey. See this link for more information on the VCF: Our HP 9845 fellow expert François Lanciault from Blainville, Canada, will show parts of his collection and live demos with his HP 9845B model 200. The exhibition contribution is titled "The Dawn of the Workstation". Take the chance to do a talk to François at the VCF about everything around the HP 9845.

New beta 6 version of HPDrive available. Some more bugs fixed, and strict mode for more precise emulation of hold-offs and error handling added. More >...

New Tutorial on HP-IB. The HP 9845 is so closely related to the Hewlett-Packard Interface Bus (HP-IB) that it was time for a dedicated tutorial. Everything you always wanted to know about the HP-IB/GPIB/IEEE-488/IEC625, about history, relevance, functional and technical basics and how it is today. More >...

Now for something completely different - I could not rest until the realization of multimedia for the HP 9845 got into reach. As everyone knows, the HP 9845 was never (really) meant for entertainment. On the other side an astonishing number of games have been developed for that system. So, what would it have been if HP's engineers had added some more mutimedia into the system, I asked myself, and tried to design a new interface board with all that what I'd like to have, all with components already available at the time of the HP 9845B. And voilà, a new project was born... More >...

The image database has been greatly extended, all models including the HP 9835A including the displays have now lots of detailed visual documentation. Check all models and displays in the hardware section. More >...

This new section shows a comparison between the HP 9845A and two other well-known computer systems of the time, the Apple II and the PET 2001. Although widely comparing apples to oranges, this gives some interesting views inside the philosophy of different systems which were developed and released at the same time. More >...

Peripherals section updated. Thanks to, many 9845 peripherals are now represented with images. More >...

Troubleshooting again simplified. After provision of the Test ROM and the TBIN mods, here now a new tutorial on how to use logic analyzers for auditing the system bus and tracing program flow in real time. More >...

Little sensation for all troubleshooters: The Test ROM code is now available for use with the ROM Board. Allows memory and cartridge drive testing even if many system components fail. Also enables bootstrapping arbitrary binary programs including the versatile TBIN test binary diagnostic program from tape or via HP-IB connection to a PC. And - last but not least - features loading a modified test binary with built-in command shell without any OS installed and a remote terminal connection via HP-IB to the PC for remote 9845 troubleshooting from a PC even with defective keyboard and CRT. More >...

New beta of HPDrive software available. Many minor and some major improvements include preliminary support for HP magtape devices like the (7970, 7974 etc.) with SIMH image file format, SIMH support for CS/80 tape drives, support for MAC and ICD interface drives (79xx) and - probably most useful - emulation for multiple drives attached to one single interface (like CS/80 combos). More >...

There is a new version of Fdio ready for download. During the last months, I have a bit lost sight of the Fdio utility, which can be used to handle non-standard (and, of course, also standard) floppy disks. Some bugs and lock-ups were to be fixed, especially concerning the use under Windows XP, and also some new features were added. You now can create a comprehensive map of your media in XML format, and also the analyze feature has been greatly revised. More >...

What would be the world without computer games... Although (or because) the HP 9845 systems had been primarily designed for engineers and scientists, there were more than 70 games in total for this platform, not counting all those which were never published. Some of the most prominent representatives are introduced within the Software Section, also there is a new tutorial section on HP 9845 game design. More >...

Dave Bryan has contributed HPDrive usage information for HP 64000 workstations and HP 1000 minis. Also, release 3.01 of HPDrive is available for download. The new release was mainly required for fixing a bug in the usage of the DlPortIo driver package. Also new presets have been added for the emulation of 79xx ICD drives. More >...

Now also the HPDir and the Fdio utilities both have left beta status and also provide Windows7 support. See the appropriate sections for downloading the new versions including new Total Commander plugins. And don't forget to give me feedback. More >...

The long awaited new release of the HPDrive mass storage emulator is now ready for download. Beyond numerous bug fixes, emulation has been functionally expanded much closer to the originals. Also, many new platforms have been added and (as far as possible) tested, like HP-UX, some measuring devices, HP 64000 workstations, HP 1000 minis and the Viper cards. NI's family of ISA or PCI based GPIB controllers is now almost completely supported. Emulation of CS/80 and SS/80 drives now includes floppy disks, hard disks and even tape drives. The custom TNT4882/TNT5004 driver now supports, of course, Windows7. Finally, due to the generic implementation and a new config file feature, you even can add your own devices. Many thanks to all those who supported this new release with their feedback, and very special thanks to Dave Bryan for his indefatigable testing and inestimable contributions. More >...

Another step into the secrets of the HP 9845 operating system: We still don't have the commented OS source code, but at least we have the symbols - many with comments - for system constants and variables. Perfect opportunity to do an update on the assembly project Asm45 - we now can disassemble LPU & PPU code with much more information included.

Asm45 now supports creating ISOURCE compatible output if you like to feed the program code into the Assembler Execution & Development ROM. Also, the system ROM listings have been updated with new disassemblies with much better readability, so if you thought about doing some reverse engineering, this is the time. More >...

Thanks to François (again) now the light pen schematics are available. So if you are a lucky owner of a 98780A enhanced monochrome or 98780A color monitor with light pen control board but don't own a light pen yet, this is the information you need to build a light pen on your own. More >...

Ultimately, 9845A ROMs have been dumped and are now available for download, both for the operating system and option ROMs. Unfortunately, the 9845A Mass Storage ROM is still missing, so if you own such ROM, and like to contribute, you are welcome. More >...

Finally, the site has been extended by the 9835 system, the smaller brother of the 9845B computer, where many of the 9845B features had been proved before they were implemented in the 9845B design, like Address Extension Chip, dual port memory access and assembly language development. Also known as 'baby' 9845. Site update for the 9835 also includes packaging information and dumps for OS ROMs and the most important Option ROMs. More >...

First bunch of software packages for the 9845 uploaded! More to come, dump by dump.. See the Software Section for details & downloads. More >...

Happy new year to all 9845 users!!

And the site keeps going:

The schematics section is growing. Now the original blueprints for the 98770A color monitor (main feature of the 9845C model) are available. Many thanks to François for providing the scans. More >...

Also, a couple of new 9845 binary programs are online, which are more than interesting for several reasons. And they have always been there in a special program from the exerciser tape for testing the enhanced monochrome monitor. New types of direct memory access are provided by the FTBIN and the WTMEMB binaries. Also new are the 79XX binary, the DEVSTA binary and the ODESSY binary. Again thanks to François for giving me the final hints. More >...

New emulator for 9111A graphics tablet and HPGL pen plotters available. Digitizer and plotter are the most useful devices for vintage HP systems immediately after a mass storage device. Use the PC with selected GPIB interfaces for digitizing input or for capturing HPGL for output on standard printers. Works with HP 9845, Series 80 and Series 200. More >...

Yes it's done! A major update of the HPDrive, HPDir and Fdio utilities now available, including support for NI PCI GPIB boards via a custom WDM driver. Now HPDrive and HPDir can comfortably be used with current PCI based GPIB boards (see the appropriate HPDrive and HPDir sections for information on which hardware is supported).

Other new features include:

Please also note that the licensing has changed (still free for non-commercial use). More >...

Mouse driver & mouse demo now support enhanced & color graphics. The MSDEMO program also has been completely revised and now supports not only color but polygon drawing, too. Also learn how to produce digital screen shots from a running application in the Using Bitmaps Tutorial. See a couple of examples in the appropriate sections. More >...

Added an article for the impressive 9845C demo within the Screen Arts section with lots of screenshots. More >...

Little sensation: Original blueprints for 9845A, 9845B and standard monitor (including graphics) available for download! Thanks to Rudolf's donation, you now can have a closer look into the technical design of the 9845 series. Nice for repair, too. See the Documents Section for download. If you need a more functional analysis, we still recommend Tony Duell's reverse engineered schematics available from

Long awaited: U.S. keyboard ROM dumps available. All ROM packages have been updated, including the EEPROM images for all major configurations and the appropriate system ROM assembler listings. See here for downloading the new ROM dumps.

Thanks to Jon from, we now have the service Test ROM and Test Tape contents online. More >...

There is now a new section for 9845 screen art, starting with still pictures from the Wargames movie. More >...