HP-50gII Discussion (split from 15c CE thread)

[LinusSch]

(08-31-2023 01:53 PM)Gilles Wrote:  Here I reach my threshold of incompetence but: if I'm not mistaken the ROM of the HP50 and 49g+ (75 MHz Samsung S3C2410A processor) is the same as the HP49g ROM (4 MHz Yorke-saturn processor). The HP50G already uses an emulation layer (the Samsung emulates the Yorke). I imagine that an HP50gII with other hardware could work by changing the emulation layer of the 50g with a new processor/hardware using most part of the 50G "rom". The newRPL approach is very different since everything is rewritten from scratch and it's a huge job.

Essentially yes. The 50g, as well as the recent 15c CE, probably the 12c as well but that is beyond my knowledge, are already using emulators running on ARM. So the art of making the old ROMs run on modern hardware is certainly alive and well. For Voyager ROMs the art of patching them for new capabilities is also available, I'm not sure whether that exists at all for RPL ROMs. There was some patching done for Emu48 but I'm not sure who and how. I also don't know (or remember) to what extent the source code for these ROMs exist somewhere, I do remember the 35s being lost.

newRPL doesn't carry any licensing hurdles (Moravia would need written permission from the team in order to use the name, but they don't even need that in order to use the code). So if they wanted to reimplement and they have the RPL sources they could rebuild on the newRPL base.