I just thought I'd drop a note, telling the list that I've fixed the bugs
in the BMVIEW program, and made some minor changes to the layout of the code.
A synopsis of the bugs:
(1) file was not opened in binary mode ("r", not "rb")
(2) a 2-byte field (I think it's a uniqueness identifier, but I'm not sure)
was not used as part of the "checksum", but should have been.
The new version can be found at:
http://www.interlog.com/~daves/pce_info/bmview.zip
And now I have a quick question for the list - does anyone know for
certain, what is the sequence of writes which enables the Backup RAM, and
what disables it ?
I seem to recall that enabling is succesive writes to $1407 - 3 specific
bytes, I think ?
And disabling is supposed to be something different ?
I am asking, because I have been playing with my Develo box lately, and
found that reading segment $F7 yields only a series of bytes equivalent to
the MSB of the address lines...
(I wonder if I can format a Develo-style MX file to download to the
machine, to unlock the RAM...)