Amiga 600

Commodore Amiga 600
Manufacturer Commodore
Type Home computer
Release date March 1992 (1992-03)
Discontinued 1993
Operating system AmigaOS 2.05
CPU Motorola 68000 @ 7.16 MHz 7.09 MHz (PAL)
Memory 1 MB (80 ns access time)
(6 MB Maximum)
Predecessor Amiga 500, Amiga 500 Plus
Successor Amiga 1200

The Amiga 600, also known as the A600 (codenamed "June Bug" after a B-52s song), is a home computer that was introduced at the CeBIT show in March 1992. The A600 was Commodore International's final model based on the Motorola 68000 CPU and the ECS chipset. It is essentially a redesign of the Amiga 500 Plus, with the option of an internal hard disk drive. A notable aspect of the A600 is its small size. Lacking a numeric keypad, the A600 is only slightly larger than a standard PC keyboard (14" long by 9.5" deep by 3" high and weighing approximately 6 pounds). It shipped with AmigaOS 2.0, which was generally considered more user-friendly than earlier versions of the operating system.

Like the A500 before it, the A600 was aimed at the lower "consumer" end of the market, with the higher end being dominated by the Amiga 3000. It was intended by manufacturer, Commodore, to revitalize sales of the A500 line before the introduction of the 32-bit Amiga 1200. According to Dave Haynie, the A600 "was supposed to be 50–60 US$ cheaper than the A500, but it came in at about that much more expensive than the A500."[1] This is supported by the fact that the A600 was originally to have been numbered the A300, positioning it as a budget version of the A500+. In the event, the cost led the machine to be marketed as a replacement for the A500+, requiring a change of number. Early models feature motherboards and power supplies with the A300 designation.

The Managing Director of Commodore UK, David Pleasance, described the A600 as a "complete and utter screw-up".[2] In comparison to the popular A500 it was considered unexpandable, did not improve on the A500's CPU, was more expensive, and lacked a numeric keypad meaning that some existing software such as flight simulators and application software could not be used without a numerical pad emulator.

An "A600HD" model was sold with an internal 2.5" ATA hard disk drive of either 20 or 40 MB. This model was marketed as a more "scholarly" version of a home computer, previously best known for its extensive range of games and retailed at almost double the price of a standard A600. However, this hard disk support introduced some issues with existing Amiga software because the memory used for hard disk control prevented some memory intensive titles from launching without disabling the hard drive (via the machine's inbuilt boot menu). Later models sold without a hard disk drive in the 'Wild, Weird and Wicked' bundle contained the A600HD label, but with the HD cradle and HD missing. These all had ROM version 37.350.

The A600 was the first Amiga model manufactured in the UK. The factory was in Irvine, Scotland, although some later examples were manufactured in Hong Kong. It was also manufactured in the Philippines. The first ever production A600—serial number "1"—resided in the Commodore UK Managing Director's office.

Surface-mount technology used on the A600 led to a failure rate under warranty of 0.78%, compared to the A500's failure rate of 8.25%.

Technical information

Processor and RAM

The A600 shipped with a Motorola 68000 CPU, running at 7.09 MHz (PAL) or 7.16 MHz (NTSC) and 1 MB "chip" RAM with 80 ns access time.[3] [4]

The designers included no capability to upgrade the original CPU as the 68000 is soldered to the motherboard and there is no other connection for upgrade. Despite this, unofficial CPU upgrades include the Motorola 68010, 68020 (at up to 25 MHz), and 68030 (at up to 50 MHz). The processor is upgraded not by replacing the 68000, but rather by fitting a connector over the CPU and commandeering the system bus.[5] However, this approach caused instability problems with some board designs, prompting custom modifications for stable operation. As a result, such CPU expansions were largely unpopular.[6]

RAM can be upgraded to a maximum of 2 MB "chip" RAM using the trapdoor expansion slot. An additional 4 MB of "fast" RAM can be added in the PC Card slot using a suitable SRAM card to realize the originally intended capacity of 6 MB. However, more "fast" RAM can be added with unofficial memory or CPU upgrades. For example, the A608 [7] board adds up to a maximum of 8 MB additional RAM by connecting over the original 68000. Likewise, CPU upgrades can accommodate up to 64 MB.[5][8]

Graphics and sound

The A600 was the last Amiga model to use Commodore's Enhanced Chip Set (ECS), which can address 2 MB of RAM and adds higher resolution display modes. The, so called, Super Agnus display chip can drive screen modes varying from 320×200 pixels to 1280×512 pixels. As with the original Amiga chipset, up to 32 colors can be displayed from a 12-bit (4096 color) palette at lower display resolutions. An extra-half-bright mode offers 64 simultaneous colors by allowing each of the 32 colors in the palette to be dimmed to half brightness. Additionally, a 4096 color "HAM" mode can be used at lower resolutions. At higher resolutions, such as 800×600i, only 4 simultaneous colors can be displayed.

Sound was unchanged from the original Amiga design, namely, 4 DMA-driven 8-bit channels, with two channels for the left speaker and two for the right.

Peripherals and expansion

The A600 features Amiga compatible connectors including two DB9M 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 A600 was compatible with many peripherals available for earlier Amiga models, such as MIDI interfaces, sound samplers and video digitizers.

Expansion capabilities new to the Amiga line were the PCMCIA Type II slot and the internal 44-pin ATA interface both most commonly seen on laptop computers. Both interfaces are controlled by the 'Gayle' custom chip. The A600 has internal housing for one 2.5" internal hard disk drive connecting to the ATA controller.[3]

The A600 was the first of only two Amiga models to feature a PCMCIA Type II interface. This connector allows use of a number of compatible peripherals available for the laptop market, though only 16-bit (Type II) PCMCIA cards are hardware compatible, newer 32-bit CardBus or PC Card peripherals are incompatible. The port is not fully compliant with the PCMCIA Type II standard as the A600 was developed before the standard was finalized. The PCMCIA implementation on the A600 is almost identical to the one featured on the later Amiga 1200. A number of Amiga peripherals were released by third-party developers for this connector including SRAM cards, CD-ROM controllers, SCSI controllers, network cards, sound samplers and video digitizers. Although PCMCIA was similar in spirit to Commodore's expansion architecture for its earlier systems, the intended capability for convenient external expansion through this connector was largely unrealized at the time of release because of the prohibitive expense of PCMCIA peripherals for a budget home computer.[9] Later, a number of compatible laptop peripherals have been made to operate with the A600 including wired and wireless network cards, serial modems and CompactFlash adaptors.

Operating system

The A600 shipped with AmigaOS 2.0, consisting of Workbench 2.0 and a Kickstart ROM chip numbered as either revision 37.299, 37.300 or 37.350 (Commodore's internal revision numbers). Confusingly, all three ROMs were officially designated as version "2.05". Early revisions of the A600 shipped with Kickstart 37.299, which had neither support for the internal ATA controller, nor for the PCMCIA interface. Although it is possible to load the necessary drivers from a floppy disk, it is not possible to boot directly from ATA or PCMCIA devices. Models fitted with Kickstart 37.300 or 37.350 can utilize those devices at boot time. Due to bugs in Kickstart 37.300, the maximum supported size of a hard disk is limited to 40 MB, and anything above this size is a game of chance. In contrast, version 37.350 is capable of supporting hard disks up to 4 GB.

Later, it was possible to buy an updated Workbench 2.1. This features a localization of the operating system in several languages and has a "CrossDOS" driver providing read/write support for FAT (MS-DOS) formatted media, such as, floppy disks or hard drives. It is a pure software update. Kickstart ROMs designated as 2.1 never existed. Workbench 2.1 runs on all Kickstart ROMs of the 2.0x family.

Following release of AmigaOS 3.1 it was possible to upgrade the A600 by installing a compatible revision 40.xx Kickstart ROM.

Specifications

A600 with part of the case removed showing the motherboard and floppy disk drive.
Attribute Specification[3]
Processor Motorola 68000 at 7.16 MHz (NTSC) or 7.09 MHz (PAL)
RAM

1 MB Amiga Chip RAM with 80 ns access time; upgradeable by further 1 MB in "trapdoor" expansion slot
Up to 4 MB in PCMCIA slot
Up to 64 MB with unofficial expansions[5] and 64/128MB with Majsta Vampire/v2 600

ROM 512 kB Kickstart ROM or 1 MB with unofficial expansions
Chipset Enhanced Chip Set (ECS)
Video 12-bit color palette (4096 colors)

Graphic modes from:

  • 320×200 to 320×512i with 32, 64 (EHB mode) or 4096 (HAM mode) on-screen colors
  • 640×200 to 640×512i with 16 on-screen colors
  • 1280×200 to 1280×512i, 640×480p60 (VGA) with 4 on-screen colors
Audio 4 × 8-bit PCM channels (2 stereo channels)

28–56 kHz maximum DMA sampling rate (dependent on video mode in use)
70 dB S/N ratio

Removable storage 3.5" DD floppy disk drive (880 kB capacity)
Internal Storage 20 or 40 MB 2.5" hard disk drive (A600HD model only)
Audio/video out Analog RGB video out (DB-23M)

Composite video out (RCA)
RF audio/video out (RCA)
Audio out (2 × RCA)

Input/output ports 2 × Mouse/Gamepad ports (DE9)

RS-232 serial port (DB-25M)
Centronics style parallel port (DB-25F)
Floppy disk drive port (DB-23F)
44-pin ATA controller (internal)
16-bit Type II PCMCIA slot

Expansion slots 80-pin expansion slot for 1 MB RAM upgrade
Operating system AmigaOS 2.0 (Workbench 2.05 and Kickstart 2.05)
Physical dimensions 350 × 240 ×75 mm (W × D × H)
Other Integrated keyboard with 78 keys (without numeric keypad)

Bundled software

In addition to the stock A600, mouse, power supply, and Workbench disks package, the A600 was available with the following software & hardware bundles:

See also

References

  1. ↑ Haynie, Dave, "Re: Amiga CPU is similar to Mac CPU", Usenet (comp.sys.mac.hardware.misc). Posted 4 November 2002, article retrieved from Google Groups archive on 9 November 2006.
  2. ↑ Tim Smith and Chris Lloyd, "Chewing the Facts", Amiga Format, Annual 1994, p 107.
  3. 1 2 3 A600 System Schematics, Commodore Electronics Limited, April 1992
  4. ↑ "A600 DRAM type and speed".
  5. 1 2 3 ACA630 short manual (PDF), individual Computers Jens Schönfeld GmbH, 2010
  6. ↑ "The Extreme Amiga 600 Upgrading Page - So how do you upgrade an Amiga 600?".
  7. ↑ http://www.a608-amiga.co.uk/
  8. ↑ "The Big Book of Amiga Hardware - Apollo 630".
  9. ↑ "The Extreme Amiga 600 Upgrading Page - What the hell is an Amiga 600?".

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