Thread: Amiga Vs ST
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Old 11 September 2014, 23:29   #485
Cyprian
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Join Date: Jul 2014
Location: Warsaw/Poland
Posts: 32
Quote:
Originally Posted by mc6809e View Post
Your calculations are only correct if you assume that all instructions need to access memory on absolutely every fourth cycle. That doesn't always happen.
yep, my calculations are pure theory, and it's just rough estimation. But I'm going to do some real tests. I'd like to compare decompression time for some packers like lz4, lz77, lz78, arj ect. in different video modes. But at the beginning I have to learn some basics of AmigaOS

Regarding blitter, I read somewhere here about 450 cycle initialization for blitter line routine, and I was curious how it looks in case of copy data initialization. That initialization (five longwords and four words) looks pretty good.


Quote:
Originally Posted by pandy71 View Post
??? how the heck ST can have 5 or 6 bitplanes? Or in other words - what do you need to do to have 5 or bitplanes on ST - how many CPU cycles?
I've just compared performance for popular video modes on ST and Amiga. And as I mentioned, those figures are pure theory.
Quote:
Originally Posted by pandy71 View Post
Classic case - mouse pointer - how many CPU cycles are used on ST to simply simulate HW sprite? Everyone calculate CPU cycles but we can't ignore OS overhead or typical functionality required by GUI.
good point. At the beginning I had an idea to compare only pure hardware with OS switched off. Now I'll try to compare also performance under OS under different video modes. Unfortunately I have no idea yet, how to change video mode in a clear, OS compatibly way. Can you advise me with links to AmigaOS for dummies?

Last edited by Cyprian; 11 September 2014 at 23:48.
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