Date   : Wed, 31 Aug 2005 00:32:22 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: Acorn OS 160K ??

"Ian Wolstenholme" <BBCMailingList@...> wrote:
> Acorn OS 64K 80K 112K 128K 144K 160K
 
plus 96K
 
> and it got me thinking about whether there were, or intended to be,
> versions of the BBC B+ with different amounts of RAM than the usual
> 64K or the rather rare 128K.
 
> The DFS 2.26 ROM must have some way of detecting how much RAM or
> sideways RAM is installed.
> 
> Has anybody tried this before or got a Beeb to come up with a memory
> message other than 64K or 128K?
 
The DFS 2 ROM serveral sideways RAM utilities including OSBYTE 68
and 69 which test how many banks of sideways RAM are present and
OSWORD 66 and 67 which transfer data to and from RAM banks.
 
It also provides service call &2B which checks how many banks of
RAM there are and displays an appropriate startup message showing
the amount of RAM present as 64+<number>*16K for a maximum of six
RAM banks. It checks for RAM in banks 15,14,13,12,1,0.
 
To display the startup message as Ian described, just do
*FX143,43,<dfs rom number>
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
There are three food groups: brown, green and ice cream.