HP-42S Emulator??


Hi All!
Where do I find the HP-42S emulator (HP42X)??
The original page said that this program is discontinued...
Very sad!
I own a HP-42S (S/N:2945B20860, ROM A-5), and it's display is getting bad. I need some alternative to use it on my PC (through Emu48) or even better if there is a emulator for PalmOS!
As I don't have any means to download it's ROM to my PC, how do I get it?
I'm thinking in create a Emu42 based on the Emu48... (as soon I translate-it to Delphi!)




Hello, country mate!

J. F. Garnier wrote an emulator for the HP42S, but I am not sure if the HP42X is the one he wrote. I'll try to find his e-mail address and I'll contact you later, O.K.?

First time around here? Good to "see" country folks. Where are you?

If you feel fine about it, e-mail me. There are other two contributors in here that live in São Paulo.

Inté! (seeyah)

Luiz Claudio

Edited: 23 July 2003, 1:21 a.m.


I'm living in Curitiba, and I'm also a HP's calculator lover. I used to own a HP-15C but in 1989 I changed it by my atual HP-42S (if I had the money in that time to keep both!)
My actual effort is to make a PalmOS based HP-42S emulator, some sort of porting of Palm's version of Emu48 but with 42S hardware. But this is not an easy quest!
I'm a Systems Analist and Programmer (Assembler and Delphi/Pascal) and another (hobby) project of mine is to create a HP-55 (and/or HP-41CX) emulator in hardware, Microchip's PIC based with LCD display or any vintage LED display I can get.

Best regards!



Although I wrote a HP-42S emulator (very basic, DOS based, semi-graphic text mode) some years ago, I never made it public. It was only a tool to study HP-42S internals.
You can use the work from Christoph Giesselink, his HP-42 emulator sources are available, and he designed a fast method for ROM transfer.



I downloaded his emulator already, but I cannot read my HP-42S's ROM because I don't have any other IR reciever besides my Palm M125, but I don't have any software that reads HP IR printing data. 8-(
I really want to read my own ROM, it is a bug-less version (no COMB bug) "A" version!
I'm working in translate all the information I gathered about the Saturn processor and HP-42S to Delphi and 68K assembler (Palm), mostly rewriting from scratch.
I'm not a "nativelly C speaking" guy, but I'll try anyway.

I have another crazy idea, about converting the ROM itself to 68K platform (sort of cross-compiling) and I/O converting to PalmOS API to run nativelly on my Palm. This could be really fast!

Best regards,



If your 42S LCD is failing (black spots), you can find a replacement in a 17B/17Bii or 27S. They all use the same LCD.


Thanks for the tip. As soon it gets bad (it only show some black spots in the left non-character area) I'll try to get one of these to replace it or search for some service to repair it.




If you look at all of the requests for a 42S emulator here and on comp.sys.hp48, there is a need for one that does not require you to have a degree in computer science and a computer workshop to download ROMs. I am one of those that would like to have and need a 42S emulator, but I do not have the computer background nor equipment to download the ROM. My thoughts are if you are going to offer an emulator for people to use, then you should provide all the components so people like myself who need it can use it. If neccessary charge something for it. I would rather pay $20-$30 for something that is complete and I can use, than to download something for free and not be able to use it because the most important item to make it run is beyond my ablility to aquire.


Hi Richard, guys;

Maybe you already know about what's written below, but it is always worth posting, right?

There is a time-consumming procedure that requires an HP42S as a source and any HP48 with INPRT program. Unfortunately this requires a lot of key pressing.

Based on the excelent Craig Finset's database, if you press [ON][LOG] and [<-] you get into standard Pioneers' memory browser/scanner (if I am not wrong, all printing capable Pioneers have it: HP17B/BII, HP27S and HP42S). Then you move the pointer to address 00000 and go pressing [COS] as many times as you can afford. Each time [COS] is pressed, data shown in the display (16 nybbles, or 8 bytes) is sent through the IR port. Any HP48 running INPRT will collect this IR sequence and "convert" it to a valid binary stream sequence. If you "upload" ROM contents in separate strings, the HP48 can be used to concatenate them or you can "join" them together after copying them all to a PC. The last ROM byte is the one at address # 1FFFFh.

As I said, it is a time consumming task. But it is not too hard to find resources to accomplish it. Now, about available time...


Luiz (Brazil)

Edited: 23 July 2003, 11:40 p.m.


The point I am trying to make is, if I DO NOT have access to a 48G and I DO NOT have access to a 48G to PC cable, how do I get a 42S ROM image to use in an emulator.


This has not happened to me, but could be a possibility.

You are out on a job site, a delivery truck, by accident, backs up over the table being used as a work bench. The 42S is crushed into a lump of shattered plastic on the ground with no hope of being fixed. This is the only calculator you own and the only HP around. eBay prices are too high to buy a replacement. Downloading an emulator is the only option left, but the emulator says the ROM image must come from your own 42S. There is no 48G and no PC cable.

How do I get the ROM to use in the program?

I'm sorry if I'm beating a dead horse here, but I am trying to look out for the people that are truly needing a solution to their problem and are hitting a brick wall.



This Message was deleted. This empty message preserves the threading when a post with followup(s) is deleted.


Nothing to say more, that's the current situation.



Buuuuutttttt . . .

If you dump and archive your -42s ROM before it gets kissed by the truck, wouldn't you be guaranteeing your right to use that ROM image henceforth? (Until, that is, you dispose of the calculator itself?)

Then, even with a smashed calculator, you'd be in a position to make legal use of its ROM . . .

(I'm no lawyer, so any damages incurred by following this advice are strictly limited to twice what you paid for the consultation.)


Hi, Paul;

Since the HP41, HP introduced a warnning in calculators' manuals about internal routines and programs. HP states they own their "copyright protected" and their use and/or copy in other systems is an infringement to their copyright protection. You have the right to use the calculator, not it's internal programs; it's assumed HP is refering to the programs developed to control the calculator itself.

After the HP41, many portable devices from HP allowed I/O activity and therefore, in almost all of the cases, downloading their O.S. was a matter of time. You'll notice that in the first HP41 manuals there's no explicit mentioneing to internal programs, but after the halfnuts it's clearly written.

At least that's what's written. Just to add a few more data.

Luiz (Brazil)



I decided to search for the warnings, and I fond the Notice that mentions them. Their text is basicaly as follows:

The programs that control your HPmodel_ID are copyrighted and all rights are reserved. Reproduction, adaptation, or translation of those programs without prior written permission of Hewlett-Packard Co. is also prohibited

Well, at least there's hope. My previous post was not accurate: HP may allow their use.

I found the text in manuals of the following models:

HP42S, HP28S, HP17BII, HP19BII, HP48, HP49.

I tried to find the same notice in existing HP41 manuals and I was not successful. My mistake.

Best regards.

Luiz (Brazil)

Edited: 26 July 2003, 12:10 a.m.


I am in the same situation here. Yesterday I found here in the Articles section a very interesting one about the signaling of the IR Printer. This can be used to build a IR-reciever-to-serial converter (with a PIC microcontroller). I'm putting this idea in my PIC's project list. If (or when) I can do this I'll tell you about.

Best regards,



You can find the full specifiaction of the HP82240B printer protocol here http://www.hpcalc.org/hp48/docs/programming/82240bte.zip.



Thanks for the link, I'll take a look.



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