ULA

Change of ULA.txt

58:751a7ca72c05
ULA.txt
     1.1 --- a/ULA.txt	Sun Mar 10 17:47:32 2013 +0100
     1.2 +++ b/ULA.txt	Sun Apr 28 22:43:13 2013 +0200
     1.3 @@ -159,8 +159,8 @@
     1.4  supposedly a replacement for the TMS4164-15 amongst many other parts. Similar
     1.5  parts include the NTE2164 and the NTE6664, both of which appear to have
     1.6  largely the same performance and connection characteristics. Meanwhile, the
     1.7 -NTE21256 appears to be a 16-pin replacement that with four times the capacity
     1.8 -that maintains the single data input and output pins. Using the NTE21256 as a
     1.9 +NTE21256 appears to be a 16-pin replacement with four times the capacity that
    1.10 +maintains the single data input and output pins. Using the NTE21256 as a
    1.11  replacement for all ICs combined would be difficult because of the single bit
    1.12  output.
    1.13  
    1.14 @@ -344,8 +344,8 @@
    1.15  input/output and the Caps Lock LED) would need to be reassigned and bit 0
    1.16  potentially being made available for use.
    1.17  
    1.18 -Palette Definition
    1.19 -------------------
    1.20 +Enhancement: Palette Definition
    1.21 +-------------------------------
    1.22  
    1.23  Since all memory accesses go via the ULA, an enhanced ULA could employ more
    1.24  specific addresses than &FE*X to perform enhanced functions. For example, the
    1.25 @@ -366,6 +366,12 @@
    1.26  from the ULA, it is likely that the ULA is expected to provide only "high" or
    1.27  "low" values.
    1.28  
    1.29 +Short of adding extra outputs from the ULA (either additional red, green and
    1.30 +blue outputs or a combined intensity output), another approach might involve
    1.31 +some kind of modulation where an output value might be encoded in multiple
    1.32 +pulses at a higher frequency than the pixel frequency. However, this would
    1.33 +demand additional circuitry outside the ULA.
    1.34 +
    1.35  Flashing Colours
    1.36  ----------------
    1.37