Amiga 2000
Encyclopedia
The Amiga 2000, or A2000, is a personal computer
released by Commodore
in 1986. It is the successor to the Amiga 1000
.
backplane, implemented in programmable logic, to the custom Amiga chipset used in the Amiga 1000
. Later improved models have redesigned hardware using the more highly integrated A500
chipset, with the additional of a gate-array called "Buster", which integrates the Zorro subsystem.. This also enabled handoff of the system control to a coprocessor slot device, and implemented the full video slot for add-on video devices.
Like the earlier Amiga 1000 and most typical PCs, and unlike the Amiga 500
, the A2000 came in a desktop case with a separate keyboard. The case was taller than the A1000 to accommodate expansion cards, two 3.5" and one 5.25" drive bays and, like a traditional PC, it lacks the "keyboard garage" of the Amiga 1000. The A2000 has space for five Zorro II
proprietary expansion slots, two 16-bit and two 8-bit ISA
slots, a CPU
upgrade slot, a video slot, and includes a battery-backed real-time clock.
The A2000 offered graphics capabilities only exceeded among its contemporaries by the Macintosh II
, a system which sold for about five times the Amiga's price. Also like the A1000, the A2000 was sold only by specialty computer dealers.
The A2000 was largely succeeded by the Amiga 3000
in 1990.
This architecture was subject to major revisions. The "B2000-CR" motherboard was the most common, showing up as the first major revision. It was designed by Dave Haynie and Terry Fisher (whose names are printed on the board) and, while an A2000 variant, was a redesign of the Amiga 1000 motherboard incorporating some Amiga 500 technological advances to achieve the "CR": Cost Reduction.
The original Amiga 2000 shipped with just a single floppy drive for storage. This was followed up fairly early by the Amiga 2000/HD, which bundled an Amiga 2090 hard drive controller and a SCSI-based hard drive. In 1988, Commodore shipped the Amiga 2500/20, which added the Amiga 2620 CPU card to the CPU slot, a 14.3MHz 68020, a 68881 FPU, and a 68851 MMU to the A2000, along with 2MB of 32-bit-wide memory. In 1989, this model was replaced by the Amiga 2500/30, which added an Amiga 2630 CPU card: 25MHz 68030 and the 68882 FPU with up to 4MB of 32-bit memory. The A2630 card could also take a memory expansion daughter card, capable of supporting up to 64MB of additional memory. Commodore built an in-house prototype of this, but never released one.
Somewhat later, Commodore UK sold a variant of the A2000, the A1500, though that model designation was not officially sanctioned by Commodore International. The A1500 shipped with dual floppy drives, and 1 MB of RAM as standard, along with the ECS
chipset and AmigaOS 2.04.
of RAM (512 kB
of "chip" RAM and 512 kB additional RAM) and either AmigaOS 1.2 or 1.3. Later revisions shipped with the improved Enhanced Chip Set, 1 MB "chip" RAM and AmigaOS 2.0.
The A2000 shipped with a Motorola 68000
CPU, running at 7.16 MHz (NTSC
) or 7.09 MHz (PAL
). The CPU can be upgraded to a 68010 by direct replacement. Official and third-party expansion boards, which fit in the CPU expansion slot, feature 68020, 68030, 68040
or 68060 microprocessors. Such upgrades may also accommodate additional RAM, FPUs, MMU
s and even SCSI
controllers.
Memory capacity varies according to the hardware revision. Certain revisions of the A2000 can be upgraded to accommodate 1 MB of chip RAM by installing an 8732A Agnus chip. Likewise, 2 MB can be accommodated by fitting an 8372B Agnus chip and adding extra memory. There is a practical limit of 8 MB of additional RAM without the use of a CPU expansion card, due to the 68000's 24-bit address bus.
The A2000 brought a new capability to the Amiga line, the Zorro II bus. This expansion bus allows installation of compatible hardware through the AutoConfig
standard, such as, graphic, sound and network cards and Parallel ATA, SCSI
and USB
controllers.
The ISA
slots can be activated by use of a "bridgeboard", which connects the Zorro II and ISA buses. Such bridgeboards typically feature on-board IBM PC Compatible
hardware, including Intel 80286
, 80386 or 80486 microprocessors allowing emulation of an entire IBM-PC system in hardware. The remaining ISA slots allow can then be used with industry standard hardware of the era, such as, network cards, graphics cards and hard drive controllers. In some A2000 models, the two 8-bit ISA slots can also be upgraded to 16-bit by fitting extension edge connector
s.
The video slot presented clocks, all 12-bits of digital video, Genlock signals, and some control lines for use to add-on cards. This allowed use of dedicated genlock
s, display de-interlacers, and video switching and effects systems such as NewTek's Video Toaster
.
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
released by Commodore
Commodore International
Commodore is the commonly used name for Commodore Business Machines , the U.S.-based home computer manufacturer and electronics manufacturer headquartered in West Chester, Pennsylvania, which also housed Commodore's corporate parent company, Commodore International Limited...
in 1986. It is the successor to the Amiga 1000
Amiga 1000
The A1000, or Commodore Amiga 1000, was Commodore's initial Amiga personal computer, introduced on July 23, 1985 at the Lincoln Center in New York City....
.
Features
Aimed at the high-end market, the original Europe-only model adds a Zorro IIZorro II
Zorro II is the name of the general purpose expansion bus used by the Amiga 2000 computer. The bus is mainly a buffered extension of the Motorola 68000 bus, with support for bus mastering DMA. The expansion slots use a 100-pin connector and the card form factor is the same as the IBM PC...
backplane, implemented in programmable logic, to the custom Amiga chipset used in the Amiga 1000
Amiga 1000
The A1000, or Commodore Amiga 1000, was Commodore's initial Amiga personal computer, introduced on July 23, 1985 at the Lincoln Center in New York City....
. Later improved models have redesigned hardware using the more highly integrated A500
Amiga 500
The Amiga 500 - also known as the A500 - was the first “low-end” Commodore Amiga 16/32-bit multimedia home/personal computer. It was announced at the winter Consumer Electronics Show in January 1987 - at the same time as the high-end Amiga 2000 - and competed directly against the Atari 520ST...
chipset, with the additional of a gate-array called "Buster", which integrates the Zorro subsystem.. This also enabled handoff of the system control to a coprocessor slot device, and implemented the full video slot for add-on video devices.
Like the earlier Amiga 1000 and most typical PCs, and unlike the Amiga 500
Amiga 500
The Amiga 500 - also known as the A500 - was the first “low-end” Commodore Amiga 16/32-bit multimedia home/personal computer. It was announced at the winter Consumer Electronics Show in January 1987 - at the same time as the high-end Amiga 2000 - and competed directly against the Atari 520ST...
, the A2000 came in a desktop case with a separate keyboard. The case was taller than the A1000 to accommodate expansion cards, two 3.5" and one 5.25" drive bays and, like a traditional PC, it lacks the "keyboard garage" of the Amiga 1000. The A2000 has space for five Zorro II
Zorro II
Zorro II is the name of the general purpose expansion bus used by the Amiga 2000 computer. The bus is mainly a buffered extension of the Motorola 68000 bus, with support for bus mastering DMA. The expansion slots use a 100-pin connector and the card form factor is the same as the IBM PC...
proprietary expansion slots, two 16-bit and two 8-bit ISA
Industry Standard Architecture
Industry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor...
slots, a CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
upgrade slot, a video slot, and includes a battery-backed real-time clock.
The A2000 offered graphics capabilities only exceeded among its contemporaries by the Macintosh II
Macintosh II
The Apple Macintosh II was the first personal computer model of the Macintosh II series in the Apple Macintosh line and the first Macintosh to support a color display.- History :...
, a system which sold for about five times the Amiga's price. Also like the A1000, the A2000 was sold only by specialty computer dealers.
The A2000 was largely succeeded by the Amiga 3000
Amiga 3000
The Commodore Amiga 3000, or A3000, was the third major release in the Amiga computer family. Released in June 1990, it features improved processing speed, improved rendering of graphics, and a new revision of the operating system...
in 1990.
Variants
The Amiga 2000 was always designed as a system platform. Commodore's engineers knew that Commodore would be unsuccessful in matching the rate of system obsolesce and replacement practiced by many in the PC industry, new models every year or so. Thus, Commodore's approach was to build a single system architecture that could span different models.This architecture was subject to major revisions. The "B2000-CR" motherboard was the most common, showing up as the first major revision. It was designed by Dave Haynie and Terry Fisher (whose names are printed on the board) and, while an A2000 variant, was a redesign of the Amiga 1000 motherboard incorporating some Amiga 500 technological advances to achieve the "CR": Cost Reduction.
The original Amiga 2000 shipped with just a single floppy drive for storage. This was followed up fairly early by the Amiga 2000/HD, which bundled an Amiga 2090 hard drive controller and a SCSI-based hard drive. In 1988, Commodore shipped the Amiga 2500/20, which added the Amiga 2620 CPU card to the CPU slot, a 14.3MHz 68020, a 68881 FPU, and a 68851 MMU to the A2000, along with 2MB of 32-bit-wide memory. In 1989, this model was replaced by the Amiga 2500/30, which added an Amiga 2630 CPU card: 25MHz 68030 and the 68882 FPU with up to 4MB of 32-bit memory. The A2630 card could also take a memory expansion daughter card, capable of supporting up to 64MB of additional memory. Commodore built an in-house prototype of this, but never released one.
Somewhat later, Commodore UK sold a variant of the A2000, the A1500, though that model designation was not officially sanctioned by Commodore International. The A1500 shipped with dual floppy drives, and 1 MB of RAM as standard, along with the ECS
Enhanced Chip Set
The Enhanced Chip Set is the second generation of the Amiga computer's chipset, offering minor improvements over the original chipset design. ECS was introduced in 1990 with the launch of the Amiga 3000. Amigas produced from 1990 onwards featured a mix of OCS and ECS chips, such as later versions...
chipset and AmigaOS 2.04.
Technical information
The majority of A2000 systems shipped with Commodore's Original Chip Set and 1 MBMegabyte
The megabyte is a multiple of the unit byte for digital information storage or transmission with two different values depending on context: bytes generally for computer memory; and one million bytes generally for computer storage. The IEEE Standards Board has decided that "Mega will mean 1 000...
of RAM (512 kB
Kilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...
of "chip" RAM and 512 kB additional RAM) and either AmigaOS 1.2 or 1.3. Later revisions shipped with the improved Enhanced Chip Set, 1 MB "chip" RAM and AmigaOS 2.0.
The A2000 shipped with a Motorola 68000
Motorola 68000
The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...
CPU, running at 7.16 MHz (NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...
) or 7.09 MHz (PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...
). The CPU can be upgraded to a 68010 by direct replacement. Official and third-party expansion boards, which fit in the CPU expansion slot, feature 68020, 68030, 68040
68040
68040 may refer to:* The Motorola 68040 computer processor chip* The Zip Code for the town of Malmo, Nebraska...
or 68060 microprocessors. Such upgrades may also accommodate additional RAM, FPUs, MMU
Memory management unit
A memory management unit , sometimes called paged memory management unit , is a computer hardware component responsible for handling accesses to memory requested by the CPU...
s and even SCSI
SCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
controllers.
Memory capacity varies according to the hardware revision. Certain revisions of the A2000 can be upgraded to accommodate 1 MB of chip RAM by installing an 8732A Agnus chip. Likewise, 2 MB can be accommodated by fitting an 8372B Agnus chip and adding extra memory. There is a practical limit of 8 MB of additional RAM without the use of a CPU expansion card, due to the 68000's 24-bit address bus.
The A2000 brought a new capability to the Amiga line, the Zorro II bus. This expansion bus allows installation of compatible hardware through the AutoConfig
Autoconfig
Autoconfig is an auto-configuration protocol of Amiga computers which is intended to automatically assign resources to expansion devices without the need for jumper settings...
standard, such as, graphic, sound and network cards and Parallel ATA, SCSI
SCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
and USB
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
controllers.
The ISA
Industry Standard Architecture
Industry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor...
slots can be activated by use of a "bridgeboard", which connects the Zorro II and ISA buses. Such bridgeboards typically feature on-board IBM PC Compatible
IBM PC compatible
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
hardware, including Intel 80286
Intel 80286
The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...
, 80386 or 80486 microprocessors allowing emulation of an entire IBM-PC system in hardware. The remaining ISA slots allow can then be used with industry standard hardware of the era, such as, network cards, graphics cards and hard drive controllers. In some A2000 models, the two 8-bit ISA slots can also be upgraded to 16-bit by fitting extension edge connector
Edge connector
An edge connector is the portion of a printed circuit board consisting of traces leading to the edge of the board that are intended to plug into a matching socket. The edge connector is a money-saving device because it only requires a single discrete female connector , and they also tend to be...
s.
The video slot presented clocks, all 12-bits of digital video, Genlock signals, and some control lines for use to add-on cards. This allowed use of dedicated genlock
Genlock
Genlock is a common technique where the video output of one source, or a specific reference signal from a signal generator, is used to synchronize other television picture sources together. The aim in video and digital audio applications is to ensure the coincidence of signals in time at a...
s, display de-interlacers, and video switching and effects systems such as NewTek's Video Toaster
Video Toaster
The NewTek Video Toaster is a combination of hardware and software for the editing and production of standard-definition and high-definition video in NTSC, PAL, and resolution independent formats on Commodore Amiga computers and subsequently on computers running the Windows operating system...
.
Specifications
| Attribute | Specification |
|---|---|
| Processor Central processing unit The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in... |
Motorola 68000 Motorola 68000 The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor... at 7.16 MHz (NTSC NTSC NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as... ) or 7.09 MHz (PAL PAL PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system... ) |
| RAM | 1 MB consisting of either:
Upgradeable to 2 MB "chip" RAM (some models require hardware modification) Upgradeable by further 8 MB without CPU upgrade or up to 128 MB with CPU upgrade |
| ROM Read-only memory Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only... |
256 or 512 kB Kickstart Kickstart (Amiga) Kickstart is a commonly used term for the bootstrap firmware of the Amiga computers developed by Commodore.Most Amiga models were shipped with the Kickstart firmware stored on ROM chips... ROM |
| Chipset | Original Chip Set (OCS) or Enhanced Chip Set (ECS) |
| Video | 12-bit color palette (4096 colors) Graphic modes with up to 32, 64 (EHB mode) or 4096 (HAM Hold-and-Modify Hold-And-Modify, usually abbreviated as HAM, is a display mode of the Commodore Amiga computer. It uses a highly unusual technique to express the color of pixels, allowing many more colors to appear on screen than would otherwise be possible.... mode) on-screen colors:
Graphic modes with up with up to 16 on-screen colors:
ECS only graphic modes:
|
| Audio | 4 × 8-bit PCM channels (2 stereo Stereophonic sound The term Stereophonic, commonly called stereo, sound refers to any method of sound reproduction in which an attempt is made to create an illusion of directionality and audible perspective... channels) 28 kHz maximum DMA Direct memory access Direct memory access is a feature of modern computers that allows certain hardware subsystems within the computer to access system memory independently of the central processing unit .... sampling rate Sampling rate The sampling rate, sample rate, or sampling frequency defines the number of samples per unit of time taken from a continuous signal to make a discrete signal. For time-domain signals, the unit for sampling rate is hertz , sometimes noted as Sa/s... 70 dB S/N ratio Signal-to-noise ratio Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power. A ratio higher than 1:1 indicates more signal than noise... |
| Internal storage Computer storage Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers.... |
3.5" SCSI SCSI Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it... hard disk drive (A2000HD only) |
| Removable storage | 3.5" DD Double density Double density, often shortened DD, is a capacity designation on magnetic storage, usually floppy disks. It describes the use of an encoding of information, which can encode on average twice as many bits per time unit compared to single density... floppy disk Floppy disk A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles... drive (880 kB capacity) |
| Audio/video ports | Analog RGB video out (DB-23M D-subminiature The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smaller connectors used on computer systems.... ) Composite video out (RCA RCA connector An RCA connector, sometimes called a phono connector or cinch connector, is a type of electrical connector commonly used to carry audio and video signals... ) Audio out (2 × RCA) Genlock Genlock Genlock is a common technique where the video output of one source, or a specific reference signal from a signal generator, is used to synchronize other television picture sources together. The aim in video and digital audio applications is to ensure the coincidence of signals in time at a... slot (internal) Video slot (internal) |
| Input/output ports | Keyboard port (5 pin DIN DIN connector A DIN connector is a connector that was originally standardized by the , the German national standards organization. There are DIN standards for a large number of different connectors, therefore the term "DIN connector" alone does not unambiguously identify any particular type of connector unless... ) 2 × Mouse/Gamepad ports (DE9 D-subminiature The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smaller connectors used on computer systems.... ) RS-232 RS-232 In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports... serial port Serial port In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time... (DB-25M) Centronics style parallel port Parallel port A parallel port is a type of interface found on computers for connecting various peripherals. In computing, a parallel port is a parallel communication physical interface. It is also known as a printer port or Centronics port... (DB-25F) Floppy disk Floppy disk A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic carrier lined with fabric that removes dust particles... drive port (DB-23F) |
| Expansion slots | 5 × 100-pin 16-bit Zorro II slots (AutoConfig Autoconfig Autoconfig is an auto-configuration protocol of Amiga computers which is intended to automatically assign resources to expansion devices without the need for jumper settings... ) 2 × 16-bit ISA Industry Standard Architecture Industry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor... slots (requires bridgeboard to activate) 2 × 8-bit ISA slots (requires bridgeboard to activate) 1 × 86-pin CPU/MMU expansion slot |
| Operating system Operating system An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system... |
AmigaOS AmigaOS AmigaOS is the default native operating system of the Amiga personal computer. It was developed first by Commodore International, and initially introduced in 1985 with the Amiga 1000... 1.2/1.3 (Kickstart 1.2/1.3 and Workbench 1.2/1.3) or AmigaOS 2.0 (Kickstart 2.04 and Workbench 2.04) |
| Other | 2 × front accessible 3.5" drive bays 1 × front accessible 5.25" drive bay Battery-backed real-time clock Real-time clock A real-time clock is a computer clock that keeps track of the current time. Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are present in almost any electronic device which needs to keep accurate time.-Terminology:The term is used to avoid... |
External links
- amigahistory.co.uk/a2000 – History of the Amiga 2000.