Original Chip Set
The OCS ( English acronym for original chip set ) was the chipset of the early Amiga models. He was installed in the Amiga 500, Amiga 1000, Amiga 1500 and Amiga 2000. It consisted of the chips Agnus, Denise and Paula. This division between the three chips was due to the limited production capabilities of the 1980s, in principle, the chips are to be regarded as a unit.
The OCS has striking similarities in architecture as in the division of functions with the also consists of three chips, ANTIC and POKEY GTIA core hardware of the Atari 8 -bit computer series, which came to market in 1979. Both chipsets were designed by Jay Miner.
The chip is responsible for the control of the chip RAM. Among other things he brings from the graphic data, which are then represented by Denise chip (see below).
Furthermore Agnus processes the various video synchronization signals and contains and controls the two coprocessors blitter and Copper.
Agnus provides the system with a powerful DMA unit available, on the one hand brings the video and sound data from the chip RAM, on the other hand also recopy data within the chip RAMs and this also process ( blit ) can, but also can generate data, namely the drawing of lines and surface filling with the blitter.
Jump to video data, which Agnus gets by DMA from the chip - RAM, include not only the pixel data palettes and sprite data and the Copper lists.
The name derives from the English words from display encoder.
In the prototype stage of the Amiga, this chip was still called Daphne.
The name Paula is derived from the English words Peripheral and audio. The chip controls the following tasks in the Amiga:
- Input and output control for disk drives
- Sound output (D / A Converters)
- Query analogue inputs and outputs
- UART for the serial interface
This chip was used in the later Amiga chipsets and was the reason why the later Amiga models were no longer appropriate in the areas covered by Paula. ( Limited data transfer rate for floppy drives, so that HD drives must run at half speed; audible sound worse than CD quality. )
In the prototype stage of the Amiga, this chip was still called Portia ( for ports and audio).
Subsequent generations: ECS, AGA, AAA
KIM- 1 • PET CBM 2001 • 3000 • 4000 • CBM CBM 8000 • MMF 9000
CBM 500 CBM * • 600 • 700 • CBM CBM 900 *
VC 10 VC 20 • • C64 (SX, GS †) • 264 series ( C16, C116, Plus / 4) • C128 • C65 *
1000 • sidecar • 500 • 2000 • CDTV † • 600 • 1200 • 4000 • • 3000/T/UX CD ³ ² †
• PC-1 PC - 10 and PC -60 • x86LT • A1060
Datasette • CBM floppy drives • VC15xx ( VC1540/41, VC1551, VC1570/71, VC1581 ) • SFD100x ( SFD1001, SFD1002 ) • CBM 2020-8250 • A570 • A590 • A3070
MPS- MPS Series • 801 • 1000 • MPS MPS 1500C • VC1520 • CBM -8000 Series • CBM 4022
Zorro bus • Watches • Port WOM • RAM Expansion Unit • Commodore mouse • monochrome and color monitors • A10 speakers • Multi-User Systems ( MBS)
Writing and desktop calculators • LED watches 2000K/3000H • † • Chessmate
MOS Technology VIC • • VIC II • TED • VDC • SID • PIA • VIA • TPI • CIA • ACIA • Agnus ( blitter, Copper) • Paula • EHB mode • HAM mode
OCS • ECS • AGA
*: Only prototype †: Console