Date   : Sat, 21 Apr 2007 14:55:58 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Z80 coprocessor cursor keys

>Message-ID: <891909.46162.qm@...>
 
Greg Cook <debounce@...> wrote:
> J.G.Harston wrote:
> 
> > Challenger introduced 640K double density disks.
> 
> Erm, 720K.  :-)  640K was ADFS.
 
2 sides * 80 tracks * 16 sectors * 256 bytes = 655360 bytes
 
Ok, yes tracks 0-2 were single density, so
 
157 * 16 * 256 + 3 * 10 * 256 = 650752 bytes = 635.5K
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
BBC BASIC for 30+ platforms - http://mdfs.net/Software/BBCBasic