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Old 14 April 2015, 10:17   #185
Toni Wilen
WinUAE developer
Join Date: Aug 2001
Location: Hämeenlinna/Finland
Age: 43
Posts: 20,635
Originally Posted by Pyromania View Post
Toni the original developers of HAM-E always claimed AGA was based on it. Now that WinUAE emulates both AGA and HAM-E can you confirm or deny this? Where they just blowing us dethered pixels?

AGA HAM8 (just like HAM-E) is extension of OCS/ECS HAM6. It is the most obvious way to extend it.

They are also slightly different:

HAM-E HAM mode bit order: xxyyyyyy
HAM8 bit order: yyyyyyxx
HAM6 bit order: --xxyyyy

xx = mode, y = RGB component value/palette index

x=0: y=palette index, x=1: y=B component, x=2: y=R, x=3: y=G. (HAM-E: x=0,y<59: use palette index y, x=0,y=59-63: select between 4 * 64 color palette banks)

I'd say HAM-E HAM mode is more direct copy (+expansion) of OCS/ECS HAM6 mode than HAM8! (Exact same mode values, exact same bit ordering).
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