Amiga 1000

Infobox computer
Photo =
Name = Commodore Amiga 1000
Type = Personal computer
Released = 24 July 1985
Discontinued = 1987
Processor = Motorola 68000 @ 7.16 MHz 7.09 MHz (PAL)
Memory = 256–512 KB (8 MB Maximum)
OS = Amiga OS 1.0

The A1000, or Commodore Amiga 1000, was Commodore's initial Amiga personal computer, introduced on July 24, 1985 at the Lincoln Center in New York City. Machines began shipping in September with a base configuration of 256KB of RAM at the retail price of US$1,295. A 13-inch analog RGB monitor was available for around US$300 bringing the price of a complete Amiga system to $1,595. Before the release of the Amiga 500 and A2000 models in 1987, the A1000 was simply called Amiga or The Amiga from Commodore.

The A1000 had a number of characteristics that distinguished it from later Amigas: It was the only model to feature the short-lived Amiga "checkmark" logo on its case; the case was elevated slightly to give a storage area for the keyboard when not in use (a "keyboard garage"); and the inside of the case was engraved with the signatures of the Amiga designers, including Jay Miner and the paw print of his dog Mitchy.

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) as opposite to ROM (Read Only Memory).

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 onboard SCSI controller.

In 2006 PC World rated the Amiga 1000 as the 7th greatest PC of all time [http://www.pcworld.com/article/id,126692-page,8-c,systems/article.html] . In 2007 it was rated by the same magazine as the 37th best tech product of all time [http://www.pcworld.com/article/id,130207-page,9-c,technology/article.html] . 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." [http://www.byte.com/art/9408/sec14/art1.htm]

Technical information

The Amiga 1000 had a 7.15909 MHz 68000 CPU (7.09 MHz for PAL machines). This is precisely double the 3.58 MHz NTSC color carrier frequency, and was needed by the Amiga chipset when outputting NTSC video. All frequencies in the Amiga 1000 are derived from this frequency as it simplified glue logic and allowed the Amiga 1000 to make do with a single cheap mass-produced crystal.

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 a TV or VCR.

It is possible to do a direct socket replacement of the standard 7 MHz 68000 CPU with a 68010 CPU. The 68010 executes instructions slightly faster than the 68000, but the conversion also introduces a small degree of software incompatibility.

Technical specifications

* CPU: Motorola 68000 (7.16 MHz NTSC, 7.09 MHz PAL)
* Chipset: OCS (Original Chipset)
**Audio (Paula):
*** 4 voices / 2 channels (Stereo)
*** 8-bit resolution / 6-bit volume
*** 28 kHz sampling rate
*** 70 dB S/N Ratio
**Video (Common resolutions):
***320×200 with 32 colors or HAM-6
***320×400i with 32 colors or HAM-6
***640×200 with 16 colors
***640×400i with 16 colors
* Memory:
** 8 KB ROM for bootstrap code.
** 256 KB WOM for the OS loaded from kickstart.
** 256 KB of Chip RAM by default, with an additional 256 KB provided by a dedicated cartridge.
** Practical upper limit of about 9 MB of Fast RAM memory due to being limited to an 24-bit address bus.
***This memory can not be utilized by the chipset, and is therefore faster.
* Removable Storage:
** 3.5" DD Floppy drive, capacity 880 KB
* Input/Output connections:
** Composite TV out (PAL versions sold in Europe and Australia, NTSC elsewhere)
** Analogue RGB video plug
** RCA audio plugs, 300 Ohm impedance.
** 2 × Game/Joy ports "(used by the mouse)"
** Keyboard port
** RS232 Serial port (DB25)
** Centronics Parallel port (DB25)
** Port for external floppy drive
** One expansion port for add-ons (memory, SCSI adaptor, etc), electrically and physically identical to the Amiga 500 expansion port (though, inexplicably, the A500's port was upside-down relative to the port on the A1000)
*** Resources handled by AutoConfig.
*Software (Bundled):
** AmigaOS 1.0/1.1/1.2 operating system, loaded from the Kickstart floppy disk at power-on.
** Microsoft Amiga BASIC
** Voice synthesis library

The two versions of the A1000

There were two versions of the Amiga 1000. The first one was sold only in Canada and the United States, had a NTSC display and lacked the EHB video mode which all other models of the Amiga had. Later models of this version would have the EHB mode built in. The second one had a PAL display, the enhanced video modes (EHB) and was built in Germany.

External links

* [http://www.old-computers.com/museum/computer.asp?st=1&c=28 The Commodore Amiga A1000 at OLD-COMPUTERS.COM]