Date   : Mon, 30 Nov 1998 19:04:51 +0000
From   : Stuart William McConnachie <stuart@...>
Subject: Re: Master OS Rom

In message <Pine.GSO.3.95-960729.981130164630.227G-
100000@...>, Tom Seddon <T.W.Seddon@...> writes
>The main bit of the Master's OS ROM is stored at $c000-$ffff, you can just
>*SAVE this as with any other ROM. As for the others you will need to save
>them all; some of the ROMs (Terminal in particular) contain segments of
>the OS which did not fit into the top 16K of memory. You can't use the
>*SAVE command for this though; you should check out the *SRREAD command
>which, if I remember correctly, will let you copy the ROM contents into
>main memory for subsequent saving. 
>
>I don't think there are any other things you need to do. The $c000-$ffff
>area is 16K, the other 7 ROMs make up the remaining 112K (the Master's
>built in ROMs are 128K in total).
There is also code in the FC00-FEFF range, ie underneath the Memory IO
range!  The master executes this on a power up or reset by disabling
interrupts and setting the bit in ACCCON which is listed in the Acorn
documentation as "Must be set to 0 at all times"!  Of course the bit is
reset once the code has been executed.  You will need to write a special
assembler routine (using ACCCON) to extract the whole OS from C000-FFFF
since C000-DFFF is the paged ROM private workspace and FC00-FEFF is the
memory IO area.

Also *SRREAD will not work for the other ROMs as Acorn have disabled
this to prevent illegal copying!

Regards,
-- 
Stuart McConnachie (stuart@...              )
43 The Hollows, Long Eaton, Nottingham, NG10 2ES, UK
Mobile: 0966 224307