Date   : Tue, 26 Feb 2008 23:14:53 +0000
From   : pete@... (Pete Turnbull)
Subject: BBC FPGA Boots to BASIC... almost...

On 26/02/2008 21:24, Mark McDougall wrote:

> Thanks for the clarification - I thought the stack was at &100 but stupid me 
> thought it grew downwards like Z80 - now I realise it would trash the 
> zero-page. That with the LDA &103,A typo it didn't hit me - DOH!

It does grow downwards like the Z80 stack, but it starts at &01FF and 
grows down toward &0100.  In fact the stack pointer is an 8-bit register 
with an additional 8 bits fixed as &01.

BASIC uses the bottom part of page 1 to store error messages, on the 
assumption that the stack will normally never get down that far.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York