1.1 --- a/ULA.txt Tue Oct 30 23:37:12 2012 +0100
1.2 +++ b/ULA.txt Sat Dec 22 01:02:20 2012 +0100
1.3 @@ -296,6 +296,21 @@
1.4 from the ULA, it is likely that the ULA is expected to provide only "high" or
1.5 "low" values.
1.6
1.7 +Flashing Colours
1.8 +----------------
1.9 +
1.10 +According to the Advanced User Guide, "The cursor and flashing colours are
1.11 +entirely generated in software: This means that all of the logical to physical
1.12 +colour map must be changed to cause colours to flash." This appears to suggest
1.13 +that the palette registers must be updated upon the flash counter - read and
1.14 +written by OSBYTE &C1 (193) - reaching zero and that some way of changing the
1.15 +colour pairs to be any combination of colours might be possible, instead of
1.16 +having colour complements as pairs. It is conceivable that the interrupt code
1.17 +responsible does the simple thing and merely inverts the current values for
1.18 +colours 8 through 15, and this might be verified by looking for an operation
1.19 +that involves the bit pattern 11001100, since this value would be EORed with
1.20 +the existing palette register values in order to perform this value inversion.
1.21 +
1.22 Palette Definition Lists
1.23 ------------------------
1.24