48G(X) serial number vs. ROM version


Is the mapping between serial number and ROM version documented somewhere? I'm most interested in when the change from ROM-P to ROM-R happened. The only thing I've found is an old post by Dave Arnett over at comp.sys.hp48 which says "...I released Rev R to production in late 1993". So, presumably the change happened late -93 or early -94 but does anyone know for shure?


You may find this info in one more recent comp.sys.hp48 FAQ you can get at:


I remember my first 48GX (Made in Singapore), purchased brand new in Aug/93, still had the Rev P ROM.




Thanks for the reply! But no, I can't find the answer in the comp.sys.hp48 FAQ ( the latest version seems to be v4.62, 14 April 2000 ). One could put the question a little different, like this: what is the highest known serial number with ROM version P ( or the lowest known number with ROM version R )?




I too am curious about the mapping of Serial Number to OS Version number and Display type (at least two types were used in the HP48G series). Also, when were double-shot injected keys done away with?



Some information about the display change ( green to black ) can be found here:

HP-48GX of black character

And about the keys: to the best of my knowledge all Singapore made HP-48 have double-shot injected keys, while the Indonesian made have painted keys. So the timeline regarding these issues is something like this:

1994-xx-yy - Change from ROM version P to R
1997-xx-yy - Manufacture moved from Singapore to Indonesia
2001-xx-yy - New "black" LCD introduced

But it really would be nice to have these dates more precise.


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