amiga advanced graphics architecture (aga) is the third generation amiga graphic chip set, first used in the amiga 4000 in 1992. before release aga was codenamed pandora by commodore international. aga was originally called aa for advanced architecture in the united states. the name was later changed to aga for the european market to reflect that it largely improved the graphical subsystem, and to avoid trademark issues.the amiga aga chipset aga is able to display graphics modes with a depth of up to  per pixel. this allows for  in indexed display modes and  (18-bit) in ham-8 (hold-and-modify) modes. the palette for the aga chipset has 256 entries from  (24-bit), whereas previous chip sets (ocs and ecs) only allowed  out of 4096 (64 colors in ehb mode). other features added to aga over ecs were super hires smooth scrolling and 32-bit fast page memory fetches to supply the graphics data bandwidth for 8 bitplane graphics modes and wider sprites. aga was an incremental upgrade, rather than the dramatic upgrade of the other chipset that commodore had begun in 1988, aaa, lacking many features that would have made it competitive with other graphic chip sets of its time. apart from the graphics data fetches, aga still operates on 16-bit data only, meaning that a lot of bandwidth is wasted during register accesses and copper and blitter operations. also the lack of a chunky graphics mode is a speed impediment to graphics operations not tailored for planar modes. in practice, the aga ham (hold-and-modify) mode is mainly useful in painting programs, picture viewers and for video playback. workbench in 256 colors is much slower than ecs operation modes for normal application use; a workaround is to use multiple screens with different color depths. aga also lacks flicker free higher resolution modes, being only able to display  at  flicker-free operation.  mode is rarely used as it could only operate at a flickering  interlaced mode. in contrast, higher-end pc systems of this era could operate  at  with a full 256-color display. aga's highest resolution is   in interlaced   when overscan was used. these missed opportunities in the aga upgrade contributed to the amiga ultimately losing technical leadership in the multimedia area. aga was to be succeeded by the [[hombre ch
Amiga AmigaOS Graphics_chips