Amiga 500
From Retrocomputing Wiki
| Amiga 500 | |
|---|---|
| Manufacturer | Commodore International |
| Type | Home computer |
| Released | 1987 |
| Introductory price | US$699, £499 |
| Discontinued | 1991 (replaced by the A500 Plus) |
| CPU | Motorola 68000 at 7.09 MHz (PAL) / 7.16 MHz (NTSC) |
| Memory | 512 KB chip RAM, expandable |
| Storage | Built-in 3.5-inch floppy drive, 880 KB |
| Display | OCS; up to 32 colours from 4,096 (4,096 in HAM mode) |
| Sound | Paula; four 8-bit PCM channels, stereo |
| Operating system | AmigaOS 1.2/1.3 (Kickstart in ROM, Workbench on disk) |
The Amiga 500, also known as the A500, is a 16-bit home computer made by Commodore International. Announced in early 1987 alongside the professional Amiga 2000, it was the low-cost model of the Amiga range and put the graphics and sound of the original Amiga 1000 into a single keyboard case. It became the best-selling Amiga by far, and in Europe it was one of the most popular games machines of the late 1980s and early 1990s.
Contents |
[edit] Background
The Amiga was designed by a small company in California, originally called Hi-Toro and later Amiga Corporation, where Jay Miner led the design of the custom chipset. Amiga ran out of money in 1984 and was bought by Commodore, which launched the Amiga 1000 in 1985. The 1000 was technically impressive but too expensive for the home market, so Commodore set out to build a cheaper version.
[edit] Hardware
Like the Atari ST, the A500 uses a Motorola 68000 processor, but most of its power comes from three custom chips, known together as the Original Chip Set (OCS):
- Agnus contains the blitter, which copies and combines blocks of graphics in memory, and the copper, a simple co-processor that can change hardware registers at chosen points on the screen.
- Denise produces the display, including eight hardware sprites. Normal modes show up to 32 colours from a palette of 4,096; Extra Half-Brite gives 64, and Hold-And-Modify (HAM) can show all 4,096 at once.
- Paula handles four channels of 8-bit sampled sound, two on each stereo side, as well as the floppy disk and serial port.
The machine has 512 KB of RAM as standard. Most owners bought the A501 expansion, which fits in a trapdoor underneath the computer and adds another 512 KB and a battery-backed clock.
[edit] Software
The operating system, AmigaOS, consists of the Kickstart ROM and the Workbench disk. It offered pre-emptive multitasking in 1985, years before the Macintosh or Windows did. Most games, however, took over the whole machine and booted directly from their own disks.
Notable games include Shadow of the Beast (1989), Lemmings (1991), Speedball 2 (1990), Sensible Soccer (1992), Turrican II and The Secret of Monkey Island. The Amiga was also popular for graphics and music work, with programs such as Deluxe Paint.
[edit] Trackers and the demoscene
In 1987 Karsten Obarski released Ultimate Soundtracker, a music program that used the four sound channels to play short samples arranged in patterns. Its file format, MOD, was copied by many later trackers such as ProTracker and is still in use today. Together with the large number of A500s in Europe, this helped the Amiga become the centre of the demoscene in the late 1980s.
[edit] Later history
In 1991 the A500 was replaced by the A500 Plus, with the Enhanced Chip Set and Kickstart 2.04, and in 1992 by the smaller A600. Commodore went bankrupt in April 1994, and the rights to the Amiga have changed hands several times since. AmigaOS 4.0 was released in December 2006 for new PowerPC-based hardware, but the classic A500 remains the machine most people mean when they talk about the Amiga.
