# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1369594778 -7200
# Node ID c0a0cfc8b94930e62de1b25997bda64199cb8e55
# Parent  b083f37c2930997087b253ec4648664b5ff03516
Added a note about a possible memory filling capability.

diff -r b083f37c2930 -r c0a0cfc8b949 ULA.txt
--- a/ULA.txt	Sat May 18 15:32:54 2013 +0200
+++ b/ULA.txt	Sun May 26 20:59:38 2013 +0200
@@ -491,6 +491,24 @@
 performance benefit would be derived from giving the CPU full access to the
 memory bandwidth.
 
+Enhancement: Memory Filling
+---------------------------
+
+A capability that could be given to an enhanced ULA is that of permitting the
+ULA to write to screen memory as well being able to read from it. Although
+such a capability would probably not be useful in conjunction with the
+existing read operations when producing a screen display, and insufficient
+bandwidth would exist to do so in high-bandwidth screen modes anyway, the
+capability could be offered during a display suspend period (as described
+above), permitting a more efficient mechanism to rapidly fill memory with a
+predetermined value.
+
+This capability could also support block filling, where the limits of the
+filled memory would be defined by the position and size of a screen area,
+although this would demand the provision of additional registers in the ULA to
+retain the details of such areas and additional logic to control the fill
+operation.
+
 Enhancement: Hardware Sprites
 -----------------------------