Amiga 1000

Amiga 1000

Amiga 1000
Amiga 1000 (1985)
Manufacturer Commodore
Type Personal computer
Release date July 23, 1985 (1985-07-23)
Discontinued 1987
Operating system AmigaOS 1.0
CPU Motorola 68000 @ 7.16 MHz (NTSC) 7.09 MHz (PAL)
Memory 256–512 KB (8.5 MB maximum)
Graphics OCS 640×512i 5-bpp
Sound Paula 4× 8-bit channels at max 28 kHz in stereo
Successor Amiga 2000

The Commodore Amiga 1000, also known as the A1000 and originally simply as the Amiga, was the first personal computer release by Commodore International in the Amiga line. It combined the powerful 16/32-bit Motorola 68000 CPU with one of the most advanced graphics and sound systems in its class, and ran a preemptive multitasking operating system that fit into 512 KB of memory.[1][2]


The A1000 has a number of characteristics that distinguish it from later Amiga models: It is the only model to feature the short-lived Amiga "check mark" logo on its case, the case is elevated slightly to give a storage area for the keyboard when not in use (a "keyboard garage"), and the inside of the case is engraved with the signatures of the Amiga designers (similar to the Macintosh); including Jay Miner and the paw print of his dog Mitchy. The A1000's case was designed by Howard Stolz.[3] As Senior Industrial Designer at Commodore, Stolz was the mechanical lead and primary interface with Sanyo in Japan, the contract manufacturer for the A1000 casing.[4]

The Amiga 1000 was manufactured in two variations: One used the NTSC television standard and the other used the PAL television standard. The NTSC variant was the initial model manufactured and sold in North America. The later PAL model was manufactured in Germany and sold in countries using the PAL television standard. The first NTSC systems lack the EHB video mode which is present in all later Amiga models.

Because AmigaOS was rather buggy at the time of the A1000's release, the OS was not placed in ROM. Instead, the A1000 included a daughterboard with 256 KB of RAM, dubbed the "Writable Control Store" (WCS), into which the core of the operating system was loaded from floppy disk (this portion of the operating system was known as the "Kickstart"). The WCS was write-protected after loading, and system resets did not require a reload of the WCS. In Europe, the WCS was often referred to as WOM (Write Once Memory), a play on the more conventional term "ROM" (Read Only Memory).

Technical information

The pre-production Amiga (which were codenamed "Velvet") released to developers in early 1985 contained 128KB of RAM with an option to expand it to 256KB. Commodore later increased the system memory to 256KB due to objections by the Amiga development team. The names of the custom chips were different, Denise and Paula was called Daphne and Portia respectively. The casing of pre-production Amiga was almost identical to the production version, the main difference was a embossed Commodore logo in the top left corner. It did not have the developer signatures or the carry handle. [5]

The Amiga 1000 has a Motorola 68000 CPU running at 7.15909 MHz (on NTSC systems) or 7.09379 MHz (PAL systems), precisely double the video color carrier frequency for NTSC or 1.6 times the color carrier frequency for PAL. The system clock timings are derived from the video frequency, which simplifies glue logic and allows the Amiga 1000 to make do with a single crystal. In keeping with its video game heritage, the chipset was designed to synchronize CPU memory access and chipset DMA so the hardware runs in real-time without wait-state delays.

Though most units were sold with an analog RGB monitor, the A1000 also had a built-in composite video output which allowed the computer to be connected directly to monitors other than their standard RGB monitor. The A1000 also had a "TV MOD" output, into which an RF Modulator could be plugged in, allowing connection to a standard TV or VCR.

The original 68000 CPU can be directly replaced with a Motorola 68010, which can execute instructions slightly faster than the 68000 but also introduces a small degree of software incompatibility. Third-party CPU upgrades, which mostly fit in the CPU socket, use faster 68020/68881 or 68030/68882 microprocessors and integrated memory. Such upgrades often have the option to revert to 68000 mode for full compatibility. Some boards have a socket to seat the original 68000, whereas the 68030 cards typically come with an on-board 68000.

The original Amiga 1000 is the only model to have 256 KB of Amiga Chip RAM, which can be expanded to 512 KB with the addition of a daughterboard under a cover in the centre front of the machine.[6] RAM may also be upgraded via official and third-party upgrades, with a practical upper limit of about 9 MB of "fast" RAM due to the 68000's 24-bit address bus. This memory is accessible only by the CPU permitting faster code execution as DMA cycles are not shared with the chipset.

The Amiga 1000 features an 86-pin expansion port (electrically identical to the later Amiga 500 expansion port, though the A500's connector is inverted). This port was utilized by third-party expansions such as memory upgrades and SCSI adaptors. These resources are handled by the Amiga Autoconfig standard. Other expansion options were available including a bus expander which provided two Zorro-II slots.


Jay Miner's signature from the top cover of a Commodore Amiga 1000 computer. The paw print is that of Mitchy, Miner's dog
Rear view of the A1000
The A1000's retail box
Attribute Specification[6]
Processor Motorola 68000 at 7.16 MHz (NTSC) or 7.09 MHz (PAL)
RAM 256 KB of Amiga Chip RAM; upgradeable to 512 KB by dedicated cartridge
ROM 8 KB bootstrap ROM. 256 KB WCS reserved for OS (loaded from the Kickstart floppy disk at power-on)
Chipset Original Chip Set (OCS)
Video 12-bit color palette (4096 colors). Graphic modes with up to 32, 64 (EHB mode; Early NTSC models do not have the EHB mode) or 4096 (HAM mode) on-screen colors:
  • 320×200 to 320×400i (NTSC)
  • 320×256 to 320×512i (PAL)

Graphic modes with up to 16 on-screen colors:

  • 640×200 to 640×400i (NTSC)
  • 640×256 to 640×512i (PAL)
Audio 4× 8-bit PCM channels (2 stereo channels); 28 kHz maximum DMA sampling rate; 70 dB S/N ratio
Removable storage 3.5" DD floppy disk drive (880 KB capacity)
Audio/video out Analog RGB video out (DB-23M); TV MOD audio/video output (for Amiga RF Modulator TV connection); Composite video out (RCA); Audio out (2× RCA)
Input/output ports Keyboard port (RJ11); 2× mouse/gamepad ports (DE9); RS-232 serial port (DB-25F); Centronics style parallel port (DB-25M); floppy disk drive port (DB-23F)
Expansion slots 86-pin expansion port
Operating system AmigaOS 1 (Kickstart 1.0/1.1/1.2/1.3 and Workbench 1.0/1.1/1.2/1.3)


Introduced on July 23, 1985 during a star-studded gala featuring Andy Warhol and Debbie Harry held at the Vivian Beaumont Theater[7] at Lincoln Center in New York City, machines began shipping in September with a base configuration of 256 KB of RAM at the retail price of US$1,295. A 13-inch (330 mm) analog RGB monitor was available for around US$300, bringing the price of a complete Amiga system to 1,595 USD. Before the release of the Amiga 500 and Amiga 2000 models in 1987, the A1000 was simply called Amiga.

In the US, the A1000 was marketed as The Amiga from Commodore, with the Commodore logo omitted from the case. The Commodore branding was retained for the international versions.

Additionally, the Amiga 1000 was sold exclusively in computer stores in the US rather than the various non computer-dedicated department and toy stores through which the VIC-20 and Commodore 64 were retailed. These measures were an effort to avoid Commodore's "toy-store" computer image created during the Tramiel era.[8][9]

Along with the operating system, the machine came bundled with a version of AmigaBASIC developed by Microsoft and a speech synthesis library developed by Softvoice, Inc.

Aftermarket upgrades

Many A1000 owners remained attached to their machines long after newer models rendered the units technically obsolete, and it attracted numerous aftermarket upgrades. Many CPU upgrades that plugged into the Motorola 68000 socket functioned in the A1000. Additionally, a line of products called the Rejuvenator series allowed the use of newer chipsets in the A1000, and an Australian-designed replacement A1000 motherboard called The Phoenix utilized the same chipset as the A3000 and added an A2000-compatible video slot and on-board SCSI controller.


In 1994, as Commodore filed for bankruptcy, Byte magazine called the Amiga 1000 "the first multimedia computer... so far ahead of its time that almost nobody—including Commodore's marketing department—could fully articulate what it was all about".[10]

In 2006, PC World rated the Amiga 1000 as the 7th greatest PC of all time.[11] In 2007, it was rated by the same magazine as the 37th best tech product of all time.[12]

See also


  1. ^
  2. ^ 256 KB ROM + 256 KB RAM
  3. ^
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  5. ^
  6. ^ a b
  7. ^
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  11. ^
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External links

  • The Commodore Amiga A1000 at OLD-COMPUTERS.COM