AGA Vs non-AGA games

[AmigaHope]

Originally Posted by LordCrass

Wasn't Pioneer Plague the first HAM game for A500? Played decently smooth too, but not a very good game.

I recall two action-type games that used HAM. Pioneer Plague and Knights of the Crystallion.

It's actually pretty easy to use HAM or HAM8 in a game without extensive recalculations, but there are some tough requirements.

A. Use HAM backgrounds but only overlay sprites.

B. Use palettes to minimize recalculations

1. Have background use only palette colors, and have any objects blitted onto it have a palette color as its leftmost pixel, and never have them overlap.

2. Have background use palette colors at known intervals, and when you overlay a blitted object, recalculate to the next palette pixel. If your objects do not use only palette colors, you also need to recalculate the objects.


When you say the AGA blitter "is faster", there is a *tiny* bit of truth to it, but not much. The AGA blitter is identical to the ECS blitter. The ECS blitter, however, can do blits twice as large as OCS, giving a tiny speedup (most of the time is spent in the copy operation, but you do save a little by having to fetch and issue fewer instructions). Since almost nothing was written ECS-specific, people considered it to be an "AGA feature".

[NovaCoder]

MooVid(Action) uses HAM8 to display movies on an AGA machine. Although it's slow on an 030 (4-8fps) @ 320x200 it can manage up to 15fps on an 060. It is of course doing a lot more than simply drawing the HAM8 screens though so I'd imagine a game could do it quite a bit faster.

I'm still trying to see if I can get a HAM8 screen working in my PC VGA port (eg if it's fast enough)....watch this space

Apparently an 060 can build (C2P) a low-res HAM screen faster than the chipram can accept it