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Advanced Amiga Architecture chipset

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This article is about the planned but never-released "AAA" Amiga chipset and is not to be confused with the upgraded graphics chipset released in 1992,Amiga Advanced Graphics Architecture (AGA).
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TheAAA chipset (Advanced Amiga Architecture) was intended to be the next-generationAmigamultimedia system designed byCommodore International. Initially begun as a secret project, the first design discussions were started in 1988, and after many revisions and redesigns the first silicon versions were fabricated in 1992–1993. The project was stymied in 1993 based on a lack of funds for chip revisions.

At the same time AAA started first silicon testing, the next generation Commodore chipset project was in progress. While AAA was a reinvention and huge upgrade of the Amiga architecture, projectHombre was essentially a clean slate. It took what was learned from Amiga and went in new directions, which included an on-chip CPU with a custom 3D instruction set, 16-bit and 24-bit chunky pixel display, and up to four 16-bit playfields running simultaneously. Hombre also embraced thePCI bus, which was seen as the future for main board interconnect and expansion going forward.

Design goals

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AAA was slated to include numerous technologies.

  • 32-bit CPU bus
  • 32-bit and 64-bit graphics bus options.
  • 256 deepCLUT entries 25-bit wide each (256 indirect colors indexed through 24-bit palette with extra genlock bit likeAGA has). This mode runs in the nativeAmigaOS display.
  • Direct 16 bit-planesplanar pixels withoutCLUT entries, since this mode doesn't contain a palette or aCLUT it requires some kind ofReTargetable Graphics (RTG) driver like chunky modes.
  • New Agnus/Alice replacement chip 'Andrea' with an updated 32-bitblitter andCopper which can handlechunky pixels.
  • A line-buffer chip withdouble buffering called 'Linda' provides higher resolution (up to 1280 × 1024). Linda also decompresses two new packed pixels (PACKLUT, PACKHY) on the fly.
  • Updated version ofPaula called 'Mary' with 8 voices that can be assigned either to left or right channel; each channel has 16-bit resolution with up to 100kHz sample rate; additionally it does 8-bit audio sampling input.
  • DirectChunky 16-bit pixels (15 bits for 32768 colors and 1 bit forgenlock overlay), provided by custom chip 'Monica', this mode requires RTG driver.
  • New 24-bit hybrid mode (with achunky/planar properties) consisted of 3 byte-planes of 8 bit chunks each. Like chunky modes it requires RTG driver for lackingCLUT.
  • New 8/4/2 bit Half-Chunky Graphics Mode which indirect throughCLUT like 8-bitplanar modes do.(requires RTG)
  • New packed (compressed) pixels (2-bit PACKLUT and 4-bit PACKHY) decompressed by Linda to 8-bit half-chunky or 24-bit Hybrid pixels respectively, used for speeding up animations.
  • A reversible pixel clock for a frame grabber (avideo capture device) inchunky modes (this only work withVRAM systems).
  • NewHold-and-Modify modes (HAM-8 chunky and HAM-10 for 24bit / 16.8 million colours).
  • Sprites size can go up to 128 pixels in width with any height.
  • Dual 8-bit playfields.
  • VRAM Chip Memory systems with optional 32/64 bitDRAM chip memory (for lower cost systems).
  • 12× to 20× memory bandwidth ofChip RAM access ofECS.
  • blitter speed increase ofAGA/ECSblitter.
  • Direct support for 4 MB rawfloppy disks (2.88MB IBM-style-formatted and all known format includingMac floppies), with a direct interface to a rawCD-ROM drive orDigital Audio Tape (DAT) and adigital radio interface, managed by Mary chip (port and audio peripheral controller).
  • Asynchronous design managed by Linda and Andrea makes AAA pixel clock independent of its bus clock so the chipset can work with any CPU (including anyRISC processor).
  • The chipset would include up to 1 milliontransistors in its 64-bit dual-system configuration (total).
  • Up to16 MBChipRAM (graphics memory) in dual-systems.
  • Two four-byte bufferedFIFO serialUARTs, one of theseUART is in the same RGA address as the original PaulaUART.
  • A built-ingenlock.
  • 40 on-demandDMA channels dynamically allocated by Andrea.
  • 64-bit pixel bus with 114MHz pixel clock in dual systems which makes 1280×1024 @72Hz screens possible.
  • 128-bit long memory bus bursts

The initialchipset run has a number of early chip problems. The LUT was scrambled, so while it was possible to put up images on the screen in test systems, it was necessary to run a bit-skiggling[clarification needed] filter that re-arranged the color to work with the existing hardware. There was a bug in the Andrea memory controller that required a FIBed die locked into either DRAM or VRAM mode. There was a bug in the Andrea bus control logic that prevented Andrea's data bus from going tri-state during DMA reads from the other chips. That prevented some important bits of the functionality of the other chips from being tested.

Three prototypes called 'Nyx', meaning "night" inClassical Greek, were built as technology demonstrators and debugger boards for the new chips. However Nyx was never intended as the final production machine, AAA systems would have been based around the Acutiator architecture designed byDave Haynie. Rather, the Nyx system was a test bed for the AAA chips and some other new ideas at Commodore, including custom memory modules for Chip RAM, Kickstart ROM on a module (with support for Flash), a multiple simultaneous pixel clock system, a low cost wired, self-terminating point to point LAN,

Commodore declared bankruptcy before designs were completed; some of the focus on AAA chips moved to creating a radically different64-bit design based on a modifiedPA-RISC 7150CPU with added graphics instructions and video pipelines (SeeHombre chipset). Fully functioning AAA chips were never produced, though they were much talked about in the trade press. Numerous plans for purchasingAmiga and salvaging the technology came and went after Commodore's demise; all of them including the realization that for the Amiga to stay competitive, the development and release of AAA or Hombre would have to be one of their overriding goals.

See also

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References

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External links

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Amiga hardware(history)
Amiga models
AmigaOne models
Unofficial 68k models
Unofficial PPC models
Amiga prototypes
Amiga chipsets
Amiga custom chips
Hardware
3rd Party Hardware
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