Amiga 4000

Infobox computer
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Name = Commodore Amiga 4000
Type = Personal computer
Released = 1992
Discontinued = 1994
Processor = Motorola 68EC030 or 68040 @ 25MHz
Memory = 2 MB~18 MB
OS = Amiga OS 3.0The Commodore Amiga 4000, or A4000, was the successor of the A2000 and A3000 computers. There are two models, the A4000/040 released in October 1992 with a Motorola 68040 CPU, and the A4000/030 released in April 1993 with a Motorola 68EC030.

The A4000 originally came in a white desktop box with a separate keyboard. Later Commodore released an expanded tower version called the A4000T.

Unlike most other Amiga models, early A4000 machines have the CPU mounted in an expansion board using a special CPU slot. The motherboard has no CPU at all. Later revisions of the A4000 have the CPU and 2 MB RAM surface mounted on the motherboard in an effort to reduce costs. These machines are known as the A4000-CR (Cost Reduced) and the surface mounted CPU is a Motorola 68EC030. The cost reduced models also made use of a Lithium-ion battery for real-time clock battery backup rather than a rechargeable NiCd battery. The NiCd backup battery is one of the most common causes of problems in an aging A4000 because it has a tendency to eventually leak. The released fluids are somewhat corrosive and can eventually damage the motherboard.

Technical information

Processor and RAM

The stock A4000 featured a Motorola 68EC030 or 68040 CPU and shipped with 2 MB of Amiga Chip RAM and up to 16 MB of additional RAM. Later, third party developers created various CPU expansion boards featuring higher rated 68040, 68060 and PowerPC CPUs. Such hardware did not only offer faster CPUs but also more and faster RAM (128 MB or greater).

Graphics and sound

The A4000 was the first Amiga model to ship with Commodore's third-generation Amiga chipset, the Advanced Graphics Architecture or AGA. As the name implies, the AGA chipset had superior graphical abilities in comparison with the earlier chipsets. However, the basic sound hardware was not upgraded and remains identical to the original Amiga 1000 (the Paula sound chip).

Peripherals and expansion

The A4000 featured Amiga compatible connectors including two DE-9 ports for joysticks, mice, and light pens, a standard 25-pin RS-232 serial port and a 25-pin Centronics parallel port. As a result the A4000 was compatible with many existing Amiga peripherals, such as, MIDI interfaces, serial modems and sound samplers.

Like the earlier Amiga 3000, the A4000 featured internal 32-bit Zorro III expansion slots which offered the use of devices, such as, graphic cards, audio cards, network cards, SCSI controllers, and later even USB controllers. One of the most notable hardware items of the era was the NewTek Video Toaster system which became popular in the 1990s for amateur and commercial desktop video production of standard-definition, broadcast quality video, comprising of tools for video switching, chroma keying, character generation, animation, and image manipulation.

Later, in an effort to offer modern expansion options third party developers created replacement expansion boards for the A4000 which provided PCI slots allowing use of higher performance and widely available PCI hardware, such as, graphic, sound and network cards.

Operating System

The A4000 shipped with AmigaOS 3.0, consisting of Workbench 3.0 and Kickstart 3.0, which together provided standard single-user operating system functionality and support for the built-in hardware. Following release of AmigaOS 3.1 it became possible to upgrade the A4000 by installing compatible Kickstart 3.1 ROM chips. The later AmigaOS 3.5 and 3.9 releases were A4000 compatible as pure software updates requiring Kickstart 3.1.

AmigaOS 4.0, a PowerPC native release of the operating system, can be used with the A4000 provided compatible PowerPC hardware is installed. Likewise, MorphOS, an alternative Amiga specific operating system can be used with this hardware.

Variants of platform independent operating systems such as Linux and BSD can also be used with the A4000.

Specifications

* CPU: Motorola 68EC030 or 68040 at 25 MHz
* Memory:
** 512 kB Kickstart ROM
** 2 MB Amiga Chip RAM
** Up to a further 16 MB RAM on board
* Chipset: AGA (Advanced Graphics Architecture)
** Video:
*** 24-bit color palette (16.8 Million colors)
*** Up to 256 on-screen colors in indexed mode
*** 262,144 on-screen colors in HAM-8 mode
*** Resolutions of up to 1280×512i (more with overscan)
*** HSync rates of 15.60-31.44 kHz
** Audio (Paula):
*** 4 hardware channels (Stereo)
*** 8-bit resolution / 6-bit volume
*** Maximum DMA sampling rate of 28-56 kHz (depending on video mode in use)
* Removable Storage:
** 3.5" HD floppy disk drive, capacity 1.76 MB
* Internal Storage:
** 40-pin buffered ATA-Controller
* Input/Output connections:
** Analogue RGB video out (DB-23M)
** Audio out (2 × RCA)
** Keyboard (6 pin mini-DIN)
** 2 × Mouse/Gamepad ports (DE9)
** RS-232 serial port (DB-25M)
** Centronics style parallel port (DB-25F)
** Floppy disk drive port (DB-23F)
* Expansion Slots:
** 4 × 100pin 32-bit Zorro III slots
** 2 × AGA video slot (inline with Zorro slot)
** 4 × 16-bit ISA slots (require bridgeboard to activate)
** 1 × 200-pin CPU expansion slot
** 4 or 5 × 72-pin SIMMs slots
*Operating System:
** AmigaOS 3.0 (Kickstart 3.0/Workbench 3.0)
*Other Characteristics:
** 2 × front accessible 3.5" drive bays
** 1 × front accessible 5.25" drive bay
** 2 × internal 3.5" drive mountings
** Key lock (disables mouse and keyboard)