=== Gate Array Register 0 - Palette Index ===
Pen index:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''bit''||Action''Value''
|-
|7..6||Must be 0|-|6||(select register 0)
|-
|5||not used
|-
|4..0||If set Palette Index (00h..0Fh=Ink 0-15, 10h=Border, 11..1Fh=same as 10h)|}Selects the palette index (to be used by next write to Palette Data). {|{{Prettytable|width: 700px; font-size: 2em;}}|''Depth''||''Normal Inks (as on CPC)''||''Secondary Inks (Aleste FUTURE Feature)''|-|1, border is selectedbit||0..1||2..3|-|2 bit||0..3||4..7
|-
|34 bit||0..015||Pen index N/A (ignored if Bit4=1=Borderuses 0..15 too)
|}