|Re: 49g+/50g v.92 ROM Upgrade|
Message #5 Posted by James M. Prange (Michigan) on 20 Apr 2007, 6:49 p.m.,
in response to message #4 by Mike (Stgt)
The revisions 2.08, 2.09, and 2.10-7 ROMs were apparently intended for only the ARM-based models (48gII, 49g+, and 50g), and never check for the possibility that they're actually running on a 49G. The VERSION command (which can be decompiled with Nosy) first checks whether it's a "Big Apple" (49g+ or 50g), and if so, whether it's a a 50g. If it's a Big Apple but not a 50g, then it must be a 49g+. If it's not a Big Apple, then it must be a 48gII, right?
But it appears that the ROM code is actually developed using a 49G, or perhaps more likely, an emulated 49G. The PC based emulator doesn't emulate the ARM processor or ARM-emulated "Saturn+" (AKA "Saturnator") processor with its additional opcodes as used in the ARM based models, but only the "hardware Saturn" with its legacy opcodes as used in the 49G. So at that point in development, it can run just fine on a 49G, although it does misidentify which model it's running on. As a final step, some legacy code is replaced with faster Saturn+ routines.
Bernard's revision 2.10-7 is also available as a .flash file for the 49G.
For information on installing 2.08 or 2.09 on a 49G, see this comp.sys.hp48 thread.
Edited: 20 Apr 2007, 6:54 p.m.