Amiga OCS/AGA
The multimedia powerhouse that introduced the world to pre-emptive multitasking and custom hardware acceleration.
Historical_Context
The Amiga 1000 launched in July 1985 with a star-studded gala at Lincoln Center, featuring Andy Warhol painting Debbie Harry on the machine. It was years ahead of its time. While the Macintosh was monochrome and the PC was beeping, the Amiga offered 4096 colors, 4-channel stereo sound, and a preemptive multitasking operating system.
Designed by Jay Miner (who also designed the Atari 2600 and 800 chips), the Amiga architecture relied on a set of custom chips that handled graphics, sound, and I/O independently of the CPU. This allowed the relatively modest Motorola 68000 CPU to outperform much faster processors in multimedia tasks.
The platform evolved from the Original Chip Set (OCS) to the Enhanced Chip Set (ECS) and finally the Advanced Graphics Architecture (AGA), which brought 256-color gaming to the masses. Despite its brilliance, strategic blunders by Commodore led to the platform's demise in 1994, but it lives on in a fervent community.
Notable_Models
Amiga 1000
1985The machine that started it all. Featuring a unique "garage" case design where the keyboard could slide underneath. It lacked Kickstart in ROM, requiring a "Kickstart Floppy" to boot.
Amiga 500
1987The best-selling Amiga. Packed the A1000 power into a consumer-friendly wedge case. The definitive gaming machine of late 80s Europe.
Amiga 2000
1987The big-box professional Amiga. Functionally identical to the A500 but with Zorro II expansion slots and a Genlock interface for video work.
Amiga 3000
1990The "Dream Machine". Introduced the ECS chipset, Zorro III, and a built-in Display Enhancer (Flicker Fixer) that allowed 31kHz VGA output.
Amiga 500+
1991A short-lived update to the A500. Featured the ECS chipset and 1MB Chip RAM standard. Famous for leaking batteries that destroyed motherboards.
Amiga 600
1992The "June Bug". Designed to be a cheap console competitor, it lacked a numeric keypad. Introduced IDE and PCMCIA to the low-end line.
Amiga 1200
1992The AGA Wedge. The most popular machine for modern demoscene productions. It brought 24-bit color and 32-bit processing to the masses.
Amiga 4000
1992The final flagship. AGA graphics with 030 or 040 power. Used standard PC IDE drives and SIMM memory to cut costs.
Amiga CD32
1993The first 32-bit CD console launched in the West. Essentially an A1200 without a keyboard, featuring a specialized Akiko chip for chunky-to-planar conversion.
Commodore CDTV
1991Commodore Dynamic Total Vision. A living room multimedia device disguised as a CD player. Essentially an A500 with a CD-ROM drive, but marketed as consumer electronics rather than a computer.
Amiga 4000T
1994The Tower. The final machine produced by Commodore before bankruptcy. A full tower version of the A4000 with more expansion capacity and SCSI as standard.
Tech_Specs
- CPU Motorola 680x0 (68000 @ 7MHz to 68060 @ 50MHz+)
- Graphics Planar Bitmapped (1 to 8 bitplanes)
- Audio 4-Channel 8-bit PCM DMA (Paula)
- OS AmigaOS (Exec Kernel + Intuition GUI)
Key_Silicon
Controls Chip RAM access. Contains the Copper (Beam sync) and Blitter (DMA graphics Mover).
Fetches bitplanes, handles sprites, and generates RGB video. AGA Lisa adds 256 colors.
4-Channel DMA sound, Floppy disk controller, Serial port, Interrupt handling.
Bus glue logic, floppy select, reset handling.