English Amiga Board - View Single Post - Atari ST graphics hardware compared to PC EGA

roondar · 20 January 2021, 11:27

Yup, the ST does not actually use of the shelf parts for graphics. It just didn't include any Dual Layer/Sprite/Blitter hardware (and also lacks the Copper).

As I understand the ST's method for display many hundreds of colours (i.e. PhotoChrome), it actually uses the CPU to rapidly set colour registers to new values as the scanline progresses. It relies on very tight timing to do so. My guess is that an Amiga equivalent should be doable, but since the Amiga already has stuff like HAM and Copper based colour reloading it's generally not done that way.

20 January 2021, 11:27	#11
roondar Registered User Join Date: Jul 2015 Location: The Netherlands Posts: 3,411	Yup, the ST does not actually use of the shelf parts for graphics. It just didn't include any Dual Layer/Sprite/Blitter hardware (and also lacks the Copper). As I understand the ST's method for display many hundreds of colours (i.e. PhotoChrome), it actually uses the CPU to rapidly set colour registers to new values as the scanline progresses. It relies on very tight timing to do so. My guess is that an Amiga equivalent should be doable, but since the Amiga already has stuff like HAM and Copper based colour reloading it's generally not done that way.