I also have a hand-held products 71MM 32K EPROM module
with some custom-programmed stuff. I just opened and,
sure enough, there is an HN27256G-25 standard EPROM
in there. There is also a jumper; does anyone know
what it is for?
As for downloading the contents of a module, well,
you can use something like this:
20 DIM A$[64]
30 A=HTD("00000") ! rom base address
40 L=64 ! length in KB
50 FOR I=0 TO L*32-1
60 A$=PEEK$(DTH$(A+I*64),64)
70 ! print A$ to your preferred output device here
80 NEXT I
To find the base address of a module, just do
ADDR$("filename"), where filename is the name
of the first file in that module; you'll get
the base address of the module plus eight.
The program above will print hex for the computer's
internal ROM. Disclaimer: program is basically
the same as that used by J.F. Garnier to extract the
firmware off HP71's for use in his emu71 emulator.
Note that if the ROM contains PRIVATE files, you will
have to use a version of PEEK$() that allows you
to look into those files; the one in the HP71 BASIC
doesn't let you do that. I know that there is a LEX
file somewhere (probably in the jyu archive) that can do it.