Date   : Tue, 09 Oct 2012 23:11:45 +0100
From   : jgh@... (J.G.Harston)
Subject: Master booting itself

An oddity with my Master 128 that started a few days ago.

Pressing Ctrl-Break boots, even though configured to NoBoot. It's
not a keyboard fault as Ctrl-Shift-Break doesn't boot, so Shift
is correctly reversing the boot status. Even odder, it sometimes
doesn't happen. About one in nine or ten Ctrl-Breaks it doesn't
boot.

OSBYTE 255 is being set to b3=0 (ie, do a boot) by the Ctrl-Break,
even though configured to NoBoot. I've tried with all ROMs unplugged
and it still does it - trying to boot from tape - so it doesn't appear
to be a ROM changing OSBYTE 255 on startup. I've tried wiping the CMOS
settings and reloading them, but that hasn't changed anything.

Anybody else seen this occuring? Another thought was maybe something in
the time is overflowing and a presumed Carry Clear is becoming Carry 
Set
somewhere (or vis versa), though I set the clock back to last year and
that didn't change anything.

-- 
J.G.Harston - jgh@...      - mdfs.net