Date   : Sat, 03 Jan 2009 03:18:48 +0000
From   : splodge@... (Richard Gellman)
Subject: My sideways ram utils

Hi,

Phill Harvey-Smith wrote:
> Sprow wrote:
>   
>> Likewise for SRLOAD, the optional 'I' parameter added to later MOS versions.
>>     
>
> What does the I flag do I've not seen that one ? At least the master ref 
>   pdf I have makes no mention of it.
>
>   
Immediate Initialisation. When loading paged ROM images in, the Master 
Compact MOS will initialise it so that its services are available 
immediately, rather than having to CTRL+BREAK first.

What it does internally is perform a rescan of the ROM sockets (possibly 
only on the ROM in question) and make notes in its internal tables as to 
which sockets actually contain anything useful, then passes a few 
service calls (e.g. allocate private RAM) so that the ROM can act as if 
its just been "started". Then when a regular service call (e.g. offer 
command) is needed, it gets passed to the new ROM as normal.

Incidentally, one of the issues of Acorn User (from 1987 I think...) 
carried a utility for other BBCs that did the same thing, offering the 
"I" functionality. Note that the "I" option is not available on the 
original Master 128/512/Turbo/ET/Domesday, only on Master Compacts or 
upgraded units.

-- Richard