Disk archival techniques

[Tony Duell]

> 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