Date   : Fri, 08 Feb 2008 13:26:52 +1100
From   : msmcdoug@... (Mark McDougall)
Subject: Text screen?

Pete Turnbull wrote:

> Very few emulators get them right; I've yet to see one that's 100%
> accurate.  The characters from an SAA5050 are much higher resolution 
> than 5x7 because of the interlacing, actually 10x14 IIRC.  That's why 
> they look less "jaggy" on a real Beeb or most other systems that use 
> SAA5050 chips.  

Actually, the ASS5050 has a "character rounding facility" that inserts a
half-dot before or after a whole dot in the presence of a diagonal in a
character matrix.

Technically, the alphanumeric characters are still defined in a 5x9 matrix,
and it's the above-mentioned rounding, not the interlacing, that produces a
better looking display.

Regards,

-- 
|              Mark McDougall                | "Electrical Engineers do it
|  <http://members.iinet.net.au/~msmcdoug>   |   with less resistance!"