The Amiga 500, also known as the A500, is the first low-end version of the
Amiga
Amiga is a family of personal computers introduced by Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly improved graphi ...
home computer. It contains the same
Motorola 68000 as the
Amiga 1000
The Commodore Amiga 1000, also known as the A1000, is the first personal computer released by Commodore International in the Amiga line. It combines the 16/32-bit Motorola 68000 CPU which was powerful by 1985 standards with one of the most adv ...
, as well as the same graphics and sound coprocessors, but is in a smaller case similar to that of the
Commodore 128
The Commodore 128, also known as the C128, C-128, C= 128,The "C=" represents the graphical part of the logo. is the last 8-bit home computer that was commercially released by Commodore Business Machines (CBM). Introduced in January 1985 at the ...
.
Commodore
Commodore may refer to:
Ranks
* Commodore (rank), a naval rank
** Commodore (Royal Navy), in the United Kingdom
** Commodore (United States)
** Commodore (Canada)
** Commodore (Finland)
** Commodore (Germany) or ''Kommodore''
* Air commodore ...
announced the Amiga 500 at the January 1987 winter
Consumer Electronics Show
CES (; formerly an initialism for Consumer Electronics Show) is an annual trade show organized by the Consumer Technology Association (CTA). Held in January at the Las Vegas Convention Center in Winchester, Nevada, United States, the event typi ...
at the same time as the high-end
Amiga 2000
The Amiga 2000, or A2000, is a personal computer released by Commodore in March 1987. It was introduced as a "big box" expandable variant of the Amiga 1000 but quickly redesigned to share most of its electronic components with the contemporary Ami ...
. It was initially available in the Netherlands in April 1987, then the rest of Europe in May. In North America and the UK it was released in October 1987 with a list price. It competed directly against models in the
Atari ST
The Atari ST is a line of personal computers from Atari Corporation and the successor to the Atari 8-bit family. The initial model, the Atari 520ST, had limited release in April–June 1985 and was widely available in July. It was the first pers ...
line.
The Amiga 500 was sold in the same retail outlets as the
Commodore 64
The Commodore 64, also known as the C64, is an 8-bit home computer introduced in January 1982 by Commodore International (first shown at the Consumer Electronics Show, January 7–10, 1982, in Las Vegas). It has been listed in the Guinness ...
, as opposed to the computer store-only Amiga 1000. It proved to be Commodore's best-selling model, particularly in Europe. Although popular with hobbyists, arguably its most widespread use was as a gaming machine, where its graphics and sound were of significant benefit. It was followed by a revised version of the computer, the
Amiga 500 Plus
The Amiga 500, also known as the A500, is the first low-end version of the Amiga home computer. It contains the same Motorola 68000 as the Amiga 1000, as well as the same graphics and sound coprocessors, but is in a smaller case similar to that ...
, and the 500 series was discontinued in 1992.
Releases
In October 1989, the Amiga 500 dropped its price from
£499 to £399 and was bundled with the ''Batman Pack'' in the United Kingdom (from October 1989 to September 1990) which included the games
''Batman'', ''
F/A-18 Interceptor'',
''The New Zealand Story'' and the bitmap graphics editor
Deluxe Paint 2. Also included was the
Amiga video connector
The Amiga video connector is a 23-pin male D-subminiature connector fitted to all personal computers in the Amiga range produced by Commodore International from 1985 to 1994, and by Escom from 1995 to 1996. The connector carries signals for anal ...
which allows the A500 to be used with a conventional CRT television.
In November 1991, the enhanced
Amiga 500 Plus
The Amiga 500, also known as the A500, is the first low-end version of the Amiga home computer. It contains the same Motorola 68000 as the Amiga 1000, as well as the same graphics and sound coprocessors, but is in a smaller case similar to that ...
replaced the 500 in some markets. It was bundled with the ''Cartoon Classics'' pack in the United Kingdom at £399, although many stores still advertised it as an 'A500'. The Amiga 500 Plus was virtually identical except for its new operating system, and in mid-1992, the two were discontinued and effectively replaced by the
Amiga 600. In late 1992, Commodore released the
Amiga 1200
The Amiga 1200, or A1200 (code-named " Channel Z"), is a personal computer in the Amiga computer family released by Commodore International, aimed at the home computer market. It was launched on October 21, 1992, at a base price of £399 in the ...
, a machine closer in concept to the original Amiga 500, but with significant technical improvements. Despite this, neither the A1200 nor the A600 replicated the commercial success of its predecessor. By this time, the home market was strongly shifting to
IBM PC compatible
IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC clones. ...
s with
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can no ...
graphics and the "low-cost"
Macintosh Classic
The Macintosh Classic is a personal computer designed, manufactured and sold by Apple Computer from October 1990 to September 1992. It was the first Macintosh to sell for less than US$1,000.
Production of the Classic was prompted by the succe ...
,
LC, and
IIsi models.
Description
Outwardly resembling the
Commodore 128
The Commodore 128, also known as the C128, C-128, C= 128,The "C=" represents the graphical part of the logo. is the last 8-bit home computer that was commercially released by Commodore Business Machines (CBM). Introduced in January 1985 at the ...
and codenamed "
Rock Lobster
"Rock Lobster" is a song written by Fred Schneider and Ricky Wilson, two members of the B-52's. It was twice recorded and released as a single, first by DB Records as their debut release in April 1978, and again the following year for the b ...
" during development, the Amiga 500's base houses a keyboard and a CPU in one shell, unlike the
Amiga 1000
The Commodore Amiga 1000, also known as the A1000, is the first personal computer released by Commodore International in the Amiga line. It combines the 16/32-bit Motorola 68000 CPU which was powerful by 1985 standards with one of the most adv ...
. The keyboard for Amiga 500s sold in the United States contains 94 keys, including ten
function key
A function key is a key on a computer or terminal keyboard that can be programmed so as to cause an operating system command interpreter or application program to perform certain actions, a form of soft key. On some keyboards/computers, function ...
s, four cursor keys, and a number pad. All European versions the keyboard have an additional two keys, except for the British variety, which still uses 94 keys. It uses a Motorola 68000 microprocessor running at in
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
regions and in
PAL
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
regions. The CPU implements a 32-bit model and has 32-bit registers, but it has a 16-bit main
ALU and uses a 16-bit external data bus and a 23-bit address bus, providing a maximum of 16 MB of
address space. Also built in to the base of the computer is a -inch floppy disk drive. The user can also install up to three external floppy drives, either - or -inch, via the disk drive port. The second and third additional drives are installed by
daisy-chaining them. Supported by these drives are double-sided disks with a capacity of 901,120 bytes, as well as 360- and 720-KB disks formatted for IBM PC compatibles.
The earliest Amiga 500 models use nearly the same
Original Amiga chipset
The Original Chip Set (OCS) is a chipset used in the earliest Commodore Amiga computers and defined the Amiga's graphics and sound capabilities. It was succeeded by the slightly improved Enhanced Chip Set (ECS) and greatly improved Advanced Gra ...
as the Amiga 1000. So graphics can be displayed in multiple resolutions and color depths, even on the same screen. Resolutions vary from 320×200 (up to 32 colors) to 640×400 (up to 16 colors) for NTSC (704×484 overscan) and 320×256 to 640×512 for PAL (704×576 overscan.)
The system uses
planar
Planar is an adjective meaning "relating to a plane (geometry)".
Planar may also refer to:
Science and technology
* Planar (computer graphics), computer graphics pixel information from several bitplanes
* Planar (transmission line technologies), ...
graphics, with up to five bitplanes (four in high resolution) allowing 2-, 4-, 8-, 16-, and 32-color screens, from a palette of 4096 colors. Two special graphics modes are also available: Extra HalfBrite, which uses a 6th bitplane as a mask to cut the brightness of any pixel in half (resulting in 32 arbitrary colors plus 32 more colors set at half the value of the first 32), and
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 ...
(HAM) which allows all 4096 colors to be used on screen simultaneously.
Later revisions of the chipset are
PAL
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
/
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
switchable in software.
The sound chip produces four hardware-mixed channels, two to the left and two to the right, of 8-bit PCM at a sampling frequency up to . Each hardware channel has its own independent volume level and sampling rate, and can be designated to another channel where it can modulate both volume and frequency using its own output. With
DMA disabled it's possible to output with a sampling frequency up to . There is a common trick to
output sound with 14-bit precision that can be combined to output 14-bit sound.
The stock system comes with
AmigaOS
AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early version ...
version 1.2 or 1.3 and of
chip RAM Chip RAM is a commonly used term for the integrated RAM used in Commodore's line of Amiga computers. Chip RAM is shared between the central processing unit (CPU) and the Amiga's dedicated chipset (hence the name). It was also, rather misleadingly, ...
(150 ns access time), one built-in double-density
standard floppy disk drive that is completely programmable and can read
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...
disks, standard Amiga disks, and up to using custom-formatting drivers.
Despite the lack of
Amiga 2000-compatible internal expansion slots, there are many ports and expansion options. There are two
DE9M Atari joystick port
The Atari joystick port is a computer port used to connect various gaming controllers to game console and home computer systems in the 1970s to the 1990s. It was originally introduced on the Atari 2600 in 1977 and then used on the Atari 400 an ...
s for
joystick
A joystick, sometimes called a flight stick, is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. A joystick, also known as the control column, is the principal cont ...
s or
mice
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
, and stereo audio
RCA connector
The RCA connector is a type of electrical connector commonly used to carry audio and video signals. The name ''RCA'' derives from the company Radio Corporation of America, which introduced the design in the 1930s. The connectors male plug an ...
s (1 V
p-p). There is a floppy drive port for daisy-chaining up to three extra floppy disk drives via a DB23F connector.
[ 070728 amigahardware.mariomisic.de] The then-standard
RS-232
In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such a ...
serial port (DB25M) and
Centronics
Centronics Data Computer Corporation was an American manufacturer of computer printers, now remembered primarily for the parallel interface that bears its name, the Centronics connector.
History
Foundations
Centronics began as a division ...
parallel port
In computing, a parallel port is a type of interface found on early computers (personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once ( parallel ...
(DB25F) are also included. The power supply is (, ).
[ 070808 ntrautanen.fi]
The system displays video in analog
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three addi ...
PAL or NTSC through a proprietary DB23M connector and in NTSC mode the line frequency is
HSync for standard video modes, which is compatible with NTSC television and CVBS/RGB video, but out of range for most
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can no ...
-compatible monitors, while a
multisync monitor
A multiple-sync (multisync) monitor, also known as a multiscan or multimode monitor, is a raster-scan analog video monitor that can properly synchronise with multiple horizontal and vertical scan rates. In contrast, fixed frequency monitors can o ...
is required for some of the higher resolutions. This connection can also be
genlock
Genlock (generator locking) 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 picture sources together. The aim in video applications is to ensure the ...
ed to an external video signal. The system was bundled with an
RF adapter to provide output on televisions with a coaxial RF input, while monochrome video is available via an
RCA connector
The RCA connector is a type of electrical connector commonly used to carry audio and video signals. The name ''RCA'' derives from the company Radio Corporation of America, which introduced the design in the 1930s. The connectors male plug an ...
(also coaxial). On the left side, behind a plastic cover, there is a Zorro (Zorro I) bus expansion external edge connector with 86 pins. Peripherals such as a hard disk drive can be added via the expansion slot and are configured automatically by the Amiga's
AutoConfig standard, so that multiple devices do not conflict with each other. Up to of so-called "fast RAM" (memory that can be accessed by the CPU only) can be added using the side expansion slot. This connector is electronically identical with the Amiga 1000's, but swapped on the other side.
The Amiga 500 has a "trap-door" slot on the underside for a RAM upgrade (typically ). This extra RAM is classified as "fast" RAM, but is sometimes referred to as "slow" RAM: due to the design of the expansion bus, it is actually on the chipset bus. Such upgrades usually include a battery-backed
real-time clock
A real-time clock (RTC) is an electronic device (most often in the form of an integrated circuit) that measures the passage of time.
Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are pr ...
. All versions of the A500 can have the additional RAM configured as chip RAM by a simple hardware modification, which involves fitting a later model (8372A)
Agnus chip. Likewise, all versions of the A500 can be upgraded to chip RAM by fitting the chip and adding additional memory.
The Amiga 500 also sports an unusual feature for a budget machine, socketed chips, which allow easy replacement of defective chips. The CPU can be directly upgraded on the motherboard to a
68010
The Motorola MC68010 processor is a 16/32-bit microprocessor from Motorola, released in 1982 as the successor to the Motorola 68000. It fixes several small flaws in the 68000, and adds a few features.
The 68010 is pin-compatible with the 68000, ...
; or to a
68020
The Motorola 68020 ("''sixty-eight-oh-twenty''", "''sixty-eight-oh-two-oh''" or "''six-eight-oh-two-oh''") is a 32-bit microprocessor from Motorola, released in 1984. A lower-cost version was also made available, known as the 68EC020. In keepin ...
,
68030
The Motorola 68030 ("''sixty-eight-oh-thirty''") is a 32-bit microprocessor in the Motorola 68000 family. It was released in 1987. The 68030 was the successor to the Motorola 68020, and was followed by the Motorola 68040. In keeping with general ...
, or
68040
The Motorola 68040 ("''sixty-eight-oh-forty''") is a 32-bit microprocessor in the Motorola 68000 series, released in 1990. It is the successor to the 68030 and is followed by the 68060, skipping the 68050. In keeping with general Motorola nami ...
via the side expansion slot; or by removing the CPU and plugging a CPU expansion card into the CPU socket (this requires opening the computer and thus voided any remaining warranty). In fact, all the custom chips can be upgraded to the
Amiga Enhanced Chip Set
The Enhanced Chip Set (ECS) is the second generation of the Amiga computer's chipset, offering minor improvements over the original chipset (OCS) design. ECS was introduced in 1990 with the launch of the Amiga 3000. Amigas produced from 1990 onw ...
(ECS) versions.
The plastic case is made of
acrylonitrile butadiene styrene
Acrylonitrile butadiene styrene (ABS) (chemical formula (C8H8)''x''·(C4H6)''y''·(C3H3N)''z'' is a common thermoplastic polymer. Its glass transition temperature is approximately . ABS is amorphous and therefore has no true melting point.
A ...
, or ABS. ABS degrades with time due to exposure to oxygen, causing a yellowing of the case. Other factors contributing to the degradation and yellowing include heat, shear, and ultraviolet light. The yellowing can be reversed by using an
optical brightener
Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs), or fluorescent whitening agents (FWAs), are chemical compounds that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the ...
, though without
stabilizing agents or antioxidants to block oxygen, the yellowing will return.
Technical specifications
![Amiga 1](https://upload.wikimedia.org/wikipedia/commons/6/6a/Amiga_1.3_and_disks.jpg)
*
OCS (1.2 & 1.3 models) or
ECS (1.3 and 500+ 2.04 models) chipset. ECS revisions of the chipset made
PAL
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
/
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
mode switchable in software.
** Sound: 4 hardware-mixed channels of 8-bit sound at up to . The hardware channels have independent volumes (65 levels) and sampling rates, and are mixed down to two fully left and fully right stereo outputs. A software controllable low-pass audio filter is also included.
* 512 KB of chip RAM (150 ns access time).
*
AmigaOS
AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early version ...
1.2 or 1.3 (upgradeable up to 3.1.4 if 2 MB of RAM are installed)
* One 3.5" double-density
floppy disk drive
A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ...
is built in, which is completely programmable and thus can read
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team ...
disks, standard Amiga disks, and up to with custom formatting (such as Klaus Deppich's diskspare.device). Uses (5 rotations/second) and .
* Built-in keyboard.
* A two-button mouse is included.
Graphics
*
PAL
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
mode: 320×256, 640×256, 640×512 (
interlaced
Interlaced video (also known as interlaced scan) is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. The interlaced signal contains two fields of a video frame captured consecutively. This ...
),
704×576 in overscan.
*
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
mode: 320×200, 640×200, 640×400 (interlaced),
704×484 in overscan.
* Graphics can be of arbitrary dimensions, resolution and colour depth, even on the same screen. The Amiga can show multiple resolution modes at the same time, splitting the screen vertically.
*
Planar
Planar is an adjective meaning "relating to a plane (geometry)".
Planar may also refer to:
Science and technology
* Planar (computer graphics), computer graphics pixel information from several bitplanes
* Planar (transmission line technologies), ...
graphics are used, with up to 5 bitplanes (4 in hires); this allowed 2, 4, 8, 16 and 32 colour screens, from a palette of 4096 colours.
* Two special graphics modes are also included:
**
Extra HalfBrite (EHB), which uses a 6th bitplane as a mask that halved the brightness of any colour seen
**
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 ...
(HAM), which allows all 4096 colours on screen at once. HAM makes it possible to use over a wide span. This works by letting each pixel position use the previous RGB value and modify one of the red, green or blue values to a new 4-bit value. This will cause some negligible colour artifacts however.
Memory
Using various expansion techniques, the A500's total RAM can reach up to 138 MB – 2 MB Chip RAM, 8 MB 16-bit Fast RAM, and 128 MB 32-bit Fast RAM.
Chip RAM
The stock 512 KB Chip RAM can be complemented by 512 KB using a "trapdoor" expansion (Commodore A501 or compatible). While that expansion memory is connected to the chip bus, hardware limitations of early stock Agnus chip revisions prevent its use as Chip RAM, only the CPU can access it. Suffering from the same contention limitations as Chip RAM, that memory is known as "Slow RAM" or "Pseudo-fast RAM". Agnus revisions shipped with late A500 are
ECS and allow use of trapdoor RAM as real Chip RAM for a total 1 MB. after changing the memory-layout jumper allows use of trapdoor RAM as real Chip RAM for a total 1 MB.
Additionally, several third-party expansions exist with up to 2 MB on the trapdoor board. Using a
Gary adapter, that memory will be mapped as either split on Chip RAM and Slow RAM or fully as Slow RAM, depending on configuration.
Furthermore, using an
A3000 Agnus on an adapter board, it is possible to expand the Chip RAM to 2 MB, matching the A500+.
Fast RAM
"Fast" RAM is located on the CPU-side bus. Its access is exclusive to the CPU and not slowed by any chipset access. The side expansion port allows for up to 8 MB of
Zorro-style expansion RAM. Alternatively, a CPU adapter allows for internal expansion.
Accelerator RAM
Internal or external CPU accelerators often include their own expansion memory. 16-bit CPUs are limited by the 24-bit address space but they can repurpose otherwise unused memory space for their included RAM. 32-bit CPU accelerators aren't limited by 24-bit addressing and can include up to 128 MB of Fast RAM (and potentially more).
Memory map
Connectors
![AMIGA500-3](https://upload.wikimedia.org/wikipedia/commons/2/2d/AMIGA500-3.jpg)
* Two
Atari joystick port
The Atari joystick port is a computer port used to connect various gaming controllers to game console and home computer systems in the 1970s to the 1990s. It was originally introduced on the Atari 2600 in 1977 and then used on the Atari 400 an ...
s for
joystick
A joystick, sometimes called a flight stick, is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. A joystick, also known as the control column, is the principal cont ...
s or
mice
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
* Stereo audio
RCA connector
The RCA connector is a type of electrical connector commonly used to carry audio and video signals. The name ''RCA'' derives from the company Radio Corporation of America, which introduced the design in the 1930s. The connectors male plug an ...
s (1 V
p-p)
* A floppy drive port (DB23F), for daisy-chaining up to 3 extra floppy disk drives via a
DB23F connector
* A standard
RS-232
In telecommunications, RS-232 or Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data. It formally defines signals connecting between a ''DTE'' (''data terminal equipment'') such a ...
serial port (DB25M)
* A
parallel port
In computing, a parallel port is a type of interface found on early computers (personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once ( parallel ...
(DB25F)
* Power inlet (, )
* Analogue
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three addi ...
50
Hz PAL and NTSC video output, provided on an Amiga-specific
DB23
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 smallest connectors used on computer systems.
Description, no ...
M
video connector. Can drive video with
HSync for standard Amiga video modes. This is not compatible with most
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can no ...
monitors. A
Multisync monitor
A multiple-sync (multisync) monitor, also known as a multiscan or multimode monitor, is a raster-scan analog video monitor that can properly synchronise with multiple horizontal and vertical scan rates. In contrast, fixed frequency monitors can o ...
is required for some higher resolutions. This connection can also be
genlock
Genlock (generator locking) 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 picture sources together. The aim in video applications is to ensure the ...
ed to an external video signal. An
RF adapter (A520) was frequently bundled with the machine to provide output on regular televisions or on
composite
Composite or compositing may refer to:
Materials
* Composite material, a material that is made from several different substances
** Metal matrix composite, composed of metal and other parts
** Cermet, a composite of ceramic and metallic materials
...
monitors. A digital 16 colour Red-Green-Blue-Intensity signal is available too on the same connector.
* Monochrome video via an
RCA connector
The RCA connector is a type of electrical connector commonly used to carry audio and video signals. The name ''RCA'' derives from the company Radio Corporation of America, which introduced the design in the 1930s. The connectors male plug an ...
*
Zorro II Zorro II is 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 ...
bus expansion on the left side behind a plastic cover
* Trapdoor slot under the machine, for RAM expansion and
real-time clock
A real-time clock (RTC) is an electronic device (most often in the form of an integrated circuit) that measures the passage of time.
Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are pr ...
Expansions
* Expansion ports are limited to a side expansion port and a trapdoor expansion on the underside of the machine. The casing can also be opened up (voiding the warranty), all larger chips are socketed rather than being
TH/
SMD soldered directly to the motherboard, so they can be replaced by hand.
* The CPU can be upgraded to a Motorola 68010 directly or to a 68020, 68030 or 68040 via the side expansion slot or a CPU socket adapter board.
* The chip RAM can be upgraded to directly on the motherboard, provided a
Fat Agnus
The MOS Technology "Agnus", usually called Agnus, is an integrated circuit in the custom chipset of the Amiga computer. The Agnus, Denise and Paula chips collectively formed the OCS and ECS chipsets.
The Agnus is the Address Generator Chip. ...
chip is also installed to support it.
* Likewise, all the custom chips can be upgraded to the
ECS chipset.
* The A500+ model instead allowed upgrading by trapdoor chip RAM without clock, but there was no visible means on board to map any of this as FAST, causing incompatibility with some stubbornly coded programs.
* There were modification instructions available for the A500 to solder or socket another RAM on the board, then run extra address lines to the trapdoor slot to accommodate an additional of fast or chip RAM depending on the installed chipset.
* Up to of "fast RAM" can be added via the side expansion slot, even more if an
accelerator with a non-EC (without reduced data/address bus) processor and 32-bit RAM is used.
* Hard drive and other peripherals can be added via the side expansion slot.
* Several companies provided combined CPU, memory and hard drive upgradesor provided chainable expansions that extended the bus as they were addedas there is only one side expansion slot.
* Expansions are configured automatically by
AutoConfig software, so multiple pieces of hardware did not conflict with each other.
Diagnostics
When the computer is powered on a self-diagnostic test is run that will indicates failure with a specific colour:
# Medium green means no chip RAM found or is damaged.
# Red means bad
kickstart-
ROM
Rom, or ROM may refer to:
Biomechanics and medicine
* Risk of mortality, a medical classification to estimate the likelihood of death for a patient
* Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac
* ...
.
# Yellow means the
CPU has crashed (no trap routine or trying to run bad code) or a bad
Zorro
Zorro ( Spanish for 'fox') is a fictional character created in 1919 by American pulp writer Johnston McCulley, appearing in works set in the Pueblo of Los Angeles in Alta California. He is typically portrayed as a dashing masked vigilante w ...
expansion card
In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus slo ...
.
# Blue means a custom chip problem (
Denise,
Paula, or
Agnus).
# Light green means
CIA
The Central Intelligence Agency (CIA ), known informally as the Agency and historically as the Company, is a civilian intelligence agency, foreign intelligence service of the federal government of the United States, officially tasked with gat ...
problem.
# Light gray means that the CIA might be defective.
# mean there is a ROM or
CIA
The Central Intelligence Agency (CIA ), known informally as the Agency and historically as the Company, is a civilian intelligence agency, foreign intelligence service of the federal government of the United States, officially tasked with gat ...
problem.
# Black-only (no video) means there is no video output.
[amiga.serveftp.net – A3000 Booting Problems]
read November 3, 2011
The keyboard
LED
A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
uses blink codes:
#One blink means the keyboard ROM has a checksum error.
#Two blinks means RAM failure.
#Three blinks means watchdog timer failure.
[
]
Trap-door expansion 501
A popular expansion for the Amiga 500 was the Amiga 501 circuit board that can be installed underneath the computer behind a plastic cover. The expansion contains RAM configured by default as " Slow RAM" or "trap-door RAM" and a battery-backed real-time clock
A real-time clock (RTC) is an electronic device (most often in the form of an integrated circuit) that measures the passage of time.
Although the term often refers to the devices in personal computers, servers and embedded systems, RTCs are pr ...
(RTC).
The 512 KB trap-door RAM and 512 KB of original chip RAM will result in 1 MB of total memory. The added memory is known as "Slow RAM", as its access is impacted by chip-bus bandwidth contention, while the chipset is not actually able to address it.
Later revisions of the motherboard provide solder-jumpers to relocate the trap-door RAM to the chip memory pool, given the Agnus chip is the newer ECS version, shipped in later A500 motherboards. Newest (rev 8) A500s would share motherboard with A500+, and configure the expansion memory as CHIP by default.
Software
Each time the Amiga 500 is booted, it executes code from the Kickstart ROM. The Amiga 500 initially came shipped with AmigaOS
AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early version ...
1.2, but units since October 1988 had version 1.3 installed.
Reception and sales
The Amiga 500 was the best-selling model in the Amiga family of computers. The German computer magazine ''Chip Chromatin immunoprecipitation (ChIP) is a type of immunoprecipitation experimental technique used to investigate the interaction between proteins and DNA in the cell. It aims to determine whether specific proteins are associated with specific genom ...
'' awarded the model the annual "Home Computer of the Year" title three consecutive times. At the European Computer Trade Show
The European Computer Trade Show (ECTS) was an annual trade show for the European video game industry which first ran in 1988, the last event being held in 2004.
The exposition was only open to industry professionals and journalists, although it w ...
1991, it also won the Leisure Award for the similar "Home Computer of the Year" title. Owing to the inexpensive cost of the Amiga 500 in then price-sensitive Europe, sales of the Amiga family of computers were strongest there, constituting 85 percent of Commodore's total sales in the fourth quarter of 1990. The Amiga 500 was widely perceived as a gaming machine and the Amiga 2000 a computer for artists and hobbyists. It has been claimed that Commodore sold as many as six million units worldwide. However, Commodore UK refuted that figure and said that the entire Amiga line sold between four and five million computers. Indeed, ''Ars Technica
''Ars Technica'' is a website covering news and opinions in technology, science, politics, and society, created by Ken Fisher and Jon Stokes in 1998. It publishes news, reviews, and guides on issues such as computer hardware and software, sci ...
'' provides a year-by-year graph of the sales of all Amiga computers.
Amiga 500 Plus
The Amiga 500 Plus (often A500 Plus or simply A500+) is a revised version of the original Amiga 500 computer. The A500+ featured minor changes to the motherboard to make it cheaper to produce than the original A500. It was notable for introducing new versions of Kickstart and Workbench
A workbench is a sturdy table at which manual work is done. They range from simple flat surfaces to very complex designs that may be considered tools in themselves. Workbenches vary in size from tiny jewellers benches to the huge benches used by ...
, and for some minor improvements in the custom chips, known as the Enhanced Chip Set
The Enhanced Chip Set (ECS) is the second generation of the Amiga computer's chipset, offering minor improvements over the original chipset (OCS) design. ECS was introduced in 1990 with the launch of the Amiga 3000. Amigas produced from 1990 o ...
(or ECS).
Although officially introduced in 1992, some Amiga 500 units sold in late 1991 actually featured the revised motherboard used in the A500+. Although the Amiga 500+ was an improvement to the Amiga 500, it was minor. It was discontinued and replaced by the Amiga 600 in summer 1992, making it the shortest-lived Amiga model.
Compatibility problems
Due to the new Kickstart v2.04, quite a few popular games (such as '' Treasure Island Dizzy'', '' SWIV'', and ''Lotus Esprit Turbo Challenge
The ''Lotus'' series consists of three racing computer games based around the Lotus brand: ''Lotus Esprit Turbo Challenge'', ''Lotus Turbo Challenge 2'', and ''Lotus III: The Ultimate Challenge''. Published between 1990 and 1992 by Gremlin Gra ...
'') failed to work on the Amiga 500+, and some people took them back to dealers demanding an original Kickstart 1.3 Amiga 500. This problem was solved by third parties who produced Kickstart ROM
Rom, or ROM may refer to:
Biomechanics and medicine
* Risk of mortality, a medical classification to estimate the likelihood of death for a patient
* Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac
* ...
switching boards, that could allow the Amiga 500+ to be downgraded to Kickstart 1.2 or 1.3. It also encouraged game developers to use better programming habits, which was important since Commodore already had plans for the introduction of the next-generation Amiga 1200
The Amiga 1200, or A1200 (code-named " Channel Z"), is a personal computer in the Amiga computer family released by Commodore International, aimed at the home computer market. It was launched on October 21, 1992, at a base price of £399 in the ...
computer. A program, Relokick, was also released (and included with an issue of CU Amiga) which loaded a Kickstart 1.3 ROM image into memory and booted the machine into Kickstart 1.3, allowing incompatible software to run. In some cases, updated compatible versions of games were later released, such as budget versions of Lotus 1 and SWIV. Double Dragon 2 by Binary Design received an update for ECS machines with the "Amiga phase-alternated linescan version 4.01/ECS". This solved compatibility issues with the graphics which appeared garbled on ECS machines, and it also slashed the in-game loading times from around 20 seconds to just over 6.
Technical specifications
* Motorola 68000 CPU running at (PAL) / (NTSC), like its predecessor
* 1 MB of Chip RAM Chip RAM is a commonly used term for the integrated RAM used in Commodore's line of Amiga computers. Chip RAM is shared between the central processing unit (CPU) and the Amiga's dedicated chipset (hence the name). It was also, rather misleadingly, ...
(very early versions came with 512 KB)
* Kickstart 2.04 (v37.175)
* Workbench 37.67 (release 2.04)
* Built-in battery backed RTC (Real Time Clock)
* Full ECS chipset including new version of the Agnus chip and Denise chip
See also
* Amiga models and variants
* Minimig
Minimig (short for ''Mini Amiga'') is an open source re-implementation of an Amiga 500 using a field-programmable gate array (FPGA).
Minimig started around January 2005 as a proof of concept by Dutch electrical engineer Dennis van Weeren. He inte ...
an open-source hardware
Open-source hardware (OSH) consists of physical artifacts of technology designed and offered by the open-design movement. Both free and open-source software (FOSS) and open-source hardware are created by this open-source culture movement and a ...
FPGA implementation
Notes
References
Further reading
*
*
*
*
*
External links
Amiga 500 Buyers guide
{{Authority control
Amiga
Products introduced in 1987
68000-based home computers