Date   : Tue, 30 Aug 1994 07:48:52 EST
From   : Stephen Quan <quan@...>
Subject: Re: BBC Default boot mode

> On power on, the BBC reads the state of the dip switches by scanning
> the keyboard matrix, the dips are just like keys themselves (either
> up or down). I believe that 3 of these combine to make the mode that
> the machine boots up in. Also, one bit is used for the Boot type
> eg. Shift-Boot, or normal boot. I'll check which ones, It reads it
> by poking SHEILA at &FE30??? (i think) to see what state they are at.

Thanks Nigel.

Yes, I am sure this must be it.  I was looking at the keypad diagram
on Appendix J of the AUG, and on the bottom row of the keypad it is
connected to the 8 bits of SW2.  Now, I have make sure my keypad is
working in order to get SW2 to work (*sigh*).
-- 
Stephen Quan (quan@...                 ), SysAdmin, Analyst/Programmer.
Centre for Spatial Information Studies, University of Tasmania, Hobart.
GPO BOX 252C, Australia, 7001.  Local Tel: (002) 202898 Fax: (002) 240282
International Callers use +6102 instead of (002).