Loading Acorn (BBC) sideways RAM.

From: Shirker <shirker_at_mooli.org.uk>
Date: Wed Oct 6 04:21:28 2004

On Fri, 17 Sep 2004, Tony Duell wrote:

> 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?

Hi Tony,

*SRLOAD imagefile baseaddress pagenumber

e.g.

*SRLOAD MYROM.ROM 8000 7

is correct for a Master, however the page at
http://homepage.ntlworld.com/rpsprowson/bbc/software/manuals/webbc.txt
says that the correct form for a machine with sideways RAM is:

*LOAD imagefile 8000

After either of these you will need to perform a hard break (Ctrl-Break).

You can check whether this worked or not with the command

*ROMS

which lists all ROMS installed in the machine.

> Is there some loader program I need (and
> where do I get it)?

It's built in.

> Anything I should know about the image file on disk
> (anything about the start/end/entry addreeses in the direxctory, for
> example)?

I believe the filename is all that's required.

This has worked for me on a MAster 128 with a copy of the Small-C Runtime
on floppy disk.

Regards,

Ed.
Received on Wed Oct 06 2004 - 04:21:28 BST

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