On the FAQ of the emu48 software, a famous emulator for HP38/39/40/48/49 calculators (https://hp.giesselink.com/emu48faq.htm#ROM), we can find the following assertion:

In general all HP-ROM files are copyrighted by Hewlett Packard. But since fall 2000 HP ACO allowed the use of the HP38, 39, 40, 48, 49 ROM's even if you're not an owner of this calculator type.

And, indeed, you can easily find on the internet (e.g. on the hpcalc.org site) various ROM dumps of the above-mentioned models. Obviously, if HP were offended by this, hpcalc.org would have received a "cease and desist" letter a long time ago.

However, I have been unable to find any reference of an actual announcement from HP on that matter.

Has there been such an official announcement, which details in which condition the ROM codes can be used freely? Or has it been something decided totally informally by HP, who is tolerating ROM code distribution and usage without saying anything?

Note: this seems even more strange if we consider that the HP48 has been discontinued as late as 2003. HP therefore gave the ROM code away before the calculators were out of production, which is rather unusual from a manufacturer.

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    I’m not adding this as an answer because it’s not authoritative, but according to this series of posts on comp.sys.hp48, this was an official decision. (Jean-Yves Avenard used to work in the calculator division at HP.) IIRC it used to be possible to download the ROMs from HP’s web site; that’s no longer the case AFAICT. Feb 13, 2018 at 10:43
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    @dim calculators were already a sideline for HP by the 90s, and calculator development had already basically shut down once, before being restarted by an Australian division in 1997. That Usenet thread came not long before the 2001 announcement that that division was to be shut down as well (later models were outsourced). I find it plausible that the ROMs were officially released at the time because the devs wanted to and management didn't care one way or another. But given all the mergers, spin-offs, and re-orgs since, it's probably impossible to get an official word from HP.
    – hobbs
    Feb 18, 2018 at 9:07
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    (Finding evidence from back then is possible. Just hard work.)
    – hobbs
    Feb 18, 2018 at 9:18
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    It would've been in keeping with HP's attitude at one time. HP knew they had an active and enthusiastic user community and went a long way towards offering support. Right after the introduction of the HP48, they even released a suite of their internal development tools. A detailed description of both the CPU architecture and system level of their OS/programming language. (This of course, formalized the work done by their user community to reverse engineer both the HP48 and earlier HP28.) hpcalc.org/details/235
    – mschaef
    Jan 23, 2019 at 15:00
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    re I have been unable to find any reference of an actual announce from HP on that matter - I have no knowledge of this particular matter, but it seems to me that companies don't "announce" such decisions. Rather, a concerned hobbyist writes to a company. and in return receives (or not) dispensation to use particular obsolete code. The recipient then reports that fact to his hobbyist community. Dec 28, 2020 at 0:44

1 Answer 1


Not officially but it was good to promote people buying them More details at http://www.hpcc.org/calculators/hp48.html

  • 6
    Mind to add some useful information here? Otherwise it'll be a link only answer which may not fit the site.
    – Raffzahn
    Oct 8, 2021 at 19:05

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