Pioneer (17B,17BII,27S,42S) ROM image download?


Hello I'm wondering if there are any interests in a quicker download of ROM images from the High End Pioneer calculators HP17B, HP17BII, HP27S, HP42S.

The ROM dump way from Jean-Francois Garnier published in HP-42S: New Facts is quite slow and needs lot of manual work.

My way needs also a HP48 as receiver with 70KB or 103KB (depends on the ROM image size (64KB/96KB)) of free memory, so a HP48G+, HP48GX or any other HP48 with merged 128KB RAM card is necessary. Further you need of course the calculator which ROM you want to copy.

The trick for the faster download is, that I use a binary data capable receiver program on the HP48 and machine written code on the Pioneer calculator. This machine code must by entered by the integrated memory scanner and may destroy the current RAM content. I takes about 5 - 10 min. to enter and verify this code. The program (~50 bytes) needs the ROM point entry of the IR transmitter function.

I know the entry of

  • HP17B rev. B
  • HP17BII rev. B
  • HP27S rev. B
  • HP42S rev. A
  • HP42S rev. B
  • HP42S rev. C
so far.

I have written a short description how to search for this address on unknown systems, most of the addresses from above have been detected by this way.

The automated download from the Pioneer calculator to the HP48 takes about 16 - 17 min. for a 64KB ROM image. Finally you have to transfer the captured string from the HP48 to a PC and decode the string on the PC with a command line program into the final ROM image. The whole process without searching for the ROM entry on unknown software revisions takes about 40 - 45 min, most time automated. The battery consumption is quite low on both calculators comparing to Jean-Francois way.

Is this interesting? I ask because the software is working, but writing the manual takes much time I wouldn't spend if there is less or no interest.

ROM images are necessary if you want to explore the operating system internals or you want to work with an emulator. I will update the HP42DEMO emulator in the next time allowing the usage of all four calculators above.

Christoph Giesselink, Homepage


Speeding up the ROM download and seeing how to insert some machine code into the source calculator both sound very interesting to me!



Thank you for all your hard work. I have a copy of your demo 42S emulator, it is most impressive.

I would be interested in this utility. I have downloaded my 42S C version with the time consuming and error prone manual method.

I would also be interested in a pre-compiled disassembler for the PC for working with the images. I have never been successful in compiling any of the sources available on the web, so I've been using my own very limited hacked together AWK program. As a result, I've never gotten very far with the study of the internals. I'm most interested in adding I/R input to the 42S.


What I am looking for is an HP 42s Emulator that is in an executable file that looks and runs like the v41 emulator on the PC. I do not have any of the java, C, Visual Basic or other compilers nor do I know how to ues them. Is there suca a program for the PC?


Because there is so less response on this request I wouldn't make the work to describe the ability of faster ROM upload.

So the links from the GPL alpha version sources of Emu42 for Win32 article are still valid.

Changes to this article

  • emulator update from 0.01alpha1 to 0.10beta1
  • compiled EXE file now included in the package
  • now works also with unpacked ROM images

Some additional remarks to the new emulator version:

The state file format is incompatible with the old emulator. I wrote a migration tool some time ago to handle different state file formats of the emulator, but I don't know if the migration tool can handle state file from 0.01alpa1. If somebody has spend many hours on entering program data to his emulated HP42S on Emu42 v0.01alpha1, and only then, and want to use this programs on the newer version, the old state file can send to me. I will validate my migration tool with this state file then. My email address can be found on my homepage. Sorry for the inconvenience, but I hate spammers.

Old KML files need also some additional work, the "Model" argument changed from "P" to "D" at the HP42 and 2nd there's the new keyword "Hardware" with the argument "Lewis" to distinguish the KML files from different emulators. This allows to copy all KML files from Emu28, Emu42 and Emu48 into one directory, but this isn't recommended. The latest KML script file documentation can be found here. The KML file in the package contain already these changes.

The emulator Emu42 base on the sources of Emu48 and is published without any support. The emulator needs a ROM image. Because of license reasons ROM images aren't part of the emulator package.

Christoph Giesselink, May 2003

Possibly Related Threads…
Thread Author Replies Views Last Post
  HP Prime Emulator download John Colvin 2 2,087 12-14-2013, 05:54 PM
Last Post: John Colvin
  17BII & 17BII+ Discounted Payback Period Revisited Tom Neudorfl 8 2,833 11-25-2013, 10:28 AM
Last Post: Don Shepherd
  How to add image to HP Forum Posting Harold A Climer 2 1,505 11-20-2013, 02:28 PM
Last Post: Han
  [Download] libhpcalcs: a toolkit for communicating with Prime calcs... debrouxl 13 4,421 11-18-2013, 05:22 AM
Last Post: debrouxl
  [Download] PrimeComm: Alternative small utility to upload/download programs to the HP Prime Erwin Ried 6 2,524 11-17-2013, 10:18 AM
Last Post: Erwin Ried
  Pioneer Variants Mark Hardman 1 1,161 11-15-2013, 10:40 PM
Last Post: Randy
  Trouble dumping Pioneer ROM via IR Neil Hamilton (Ottawa) 6 2,468 06-20-2013, 08:14 AM
Last Post: Neil Hamilton (Ottawa)
  HP-27S speed compared to HP-42S Tommi 3 1,760 06-05-2013, 05:55 PM
Last Post: Christoph Giesselink
  HP85 Programmable ROM cardtridge 82929A-service ROM not working- inaki 2 1,860 04-25-2013, 08:08 AM
Last Post: inaki
  [41CL] Repairing an image in Flash Monte Dalrymple 0 886 01-24-2013, 07:01 PM
Last Post: Monte Dalrymple

Forum Jump: