Loading Acorn (BBC) sideways RAM.

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Sep 16 19:04:31 2004

This is a really trivial question, but I wasn't really a BBC micro hacker
in the old days,

I am planning some upgrdes to a BBC Model B+ (the fact that this
particular B+ lives in the bottom of an Acorn Cambridge shouldn't
matter...). One of them is to combine some of the ROMs (the B+ can take
27256 32K byte EPROMs), thus freeing up some ROM sockets and put a RAM
chip in one of them. I then have to fiddle the write-enable line [1] (should
be easy) and I have 32K of sideways RAM.

The hardware doens't worry me (I have schematics...). But how do I load a
ROM image into the sideways RAM? Is there some loader program I need (and
where do I get it)? Anything I should know about the image file on disk
(anything about the start/end/entry addreeses in the direxctory, for
example)?


[1] I believe it's a good idea to be able to write-protect the sideways
RAM, but I don't want to drill holes in my Cambridge. Has anoyne ever
used the cassette motor line for this? Seems like an obvious thing to use.

-tony
Received on Thu Sep 16 2004 - 19:04:31 BST