18 May
2005
18 May
'05
5:12 p.m.
Plus one ROM archive might be intended to be spread
across several
physical chips in some way. I've certainly got ROM images saved from 32-
bit machines where four physical 8-bit chips are accessed in parallel.
For the native machine they're accessed that way; for browsing in a hex
editor or maybe use with an emulator, it'd be handy to have them as a
linear sequence of bytes. Maybe for that reason some essence of the data
organisation also needs to be captured in the image archive...
This, IMHO, is a non-problem. Unlike a floppy disk, where there is
information other than the user data in the sectors, and where losing
things like the inter-sector gap size _is_ a loss of information, you get
the same infromation whether your ROM dump is 16K 32 bit words as the
processor would read them, or 4 off 16K byte files, dumped from each
EPROM.
Even with my limited programming skills I can write a program to convert
one into the other (and, if necessary scramble the order of address and
data pins if they were not connected in the obvious order). Said programs
may not been neat or efficient, but they only generally get run once, so
it doesn't really matter.
Of coruse it's _essential_ to record just what each file consists of, and
if possible to explain how it corresponds to the real hardware. I am
particularly bad about doing the latter, since I tend to assume it's
obvious from the schematics, which I am likely to have anyway.
-tony