Editing Amiga 2000 (section)

==Variants==
The Amiga 2000 was designed with an [[open architecture]]. Commodore's engineers believed that the company would probably be unsuccessful in matching the rate of system obsolesce and replacement then common in the PC industry, with new models every year or so. Commodore's approach was to build a single system architecture that could span different models. Commodore was so successful at this that [[.info magazine|Info magazine]] judged that the A2000 would not become obsolete "until well after the turn of the century"<ref name="im87" /> at the earliest.

The final design was the result of an internal battle within Commodore, which pitted the USA division, who wanted to build a system more like the Amiga 3000 (and 1000), against the German division, which was fresh from the successful introduction of the first [[Commodore PC-compatible systems]] and planned to include this capability in the Amiga 2000 from the start.<ref>{{cite web|title=Commodore Amiga 2000 Teardown |date=March 7, 2011 |access-date=December 6, 2014 |url=http://www.techrepublic.com/pictures/commodore-amiga-2000-teardown/1/ }}</ref> The bottom-line practicality of the German design won out, and the final A2000 shipped with not only Zorro II slots, but a complement of PC standard (for the day) ISA slots.

This architecture was subject to major revisions. The original motherboard was based on the previous Amiga 1000 with the addition of expansion slots, and so suffered all the same limitations. This was soon replaced by the "B2000-CR" version designed by [[Dave Haynie]] and Terry Fisher (whose names are printed on the board), which was instead based on the Amiga 500's improved design. The practical differences are that the early 2000 motherboard only has 512 kilobytes of ram installed, cannot be upgraded with newer versions of the chipset, requires the original processor to be removed when installing a processor card, and cannot use a video slot mounted [[flicker fixer]].

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 14.3&nbsp;MHz [[68020]], a [[68881]] FPU, and a [[68851]] MMU to the A2000, along with 2&nbsp;MB of 32-bit-wide memory. The A2000's original 68000 CPU remained installed on the motherboard of these machines and could be switched to by holding down the right mouse button when powering on the computer for better compatibility. In 1989 this model was replaced by the Amiga 2500/30, which added an Amiga 2630 CPU card: 25&nbsp;MHz [[68030]] and the [[68882]] FPU with up to 4&nbsp;MB of 32-bit memory. The A2630 card can also take a memory expansion daughter card, capable of supporting up to 64&nbsp;MB of additional memory. Commodore built an in-house prototype of this, but never released one.

===Amiga 1500 {{anchor|Amiga1500}}===
{{Infobox computer
| Photo = 
| Name = Amiga 1500
| Type = [[Personal computer]]
| Released = {{Start date and age|1990}}
| price = £999
| Discontinued = 
| Processor = {{nowrap|[[Motorola 68000]]}} {{nowrap|@ 7.16&nbsp;MHz ([[NTSC]])}} {{nowrap|7.09&nbsp;MHz ([[PAL]])}}
| Memory = 1 [[megabyte|MB]]
| OS = Kickstart 1.3 / AmigaOS 1.3
| predecessor = 
| successor = 
| units sold = 
}}

In 1990, Commodore UK sold a variant of the A2000, the A1500, for £999. The model designation was not officially sanctioned by Commodore International. The A1500 shipped with dual floppy drives, and 1&nbsp;MB of ChipRAM as standard. Initial units came with Kickstart 1.3 (and thus AmigaOS 1.3), though the Original Chipset onboard includes a later Agnus revision allowing the 1MB of ChipRAM. Early machines were bundled with a Commodore 1084SD1 monitor. Later machines came with the [[Enhanced Chip Set|ECS]] chipset and AmigaOS 2.04. The second floppy drive replaces the [[hard disk drive]]. The A1500 has no hard disk drive as standard and as the only significant difference the A1500s could be upgraded into A2000/HDs by addition of a hard disk controller (and associated drive).

There was also a replacement case kit for the [[Amiga 500]] made by [[Checkmate Digital]] and also called A1500.<ref>[http://www.amiga-hardware.com/showhardware.cgi?HARDID=6 Checkmate Digital: Checkmate A1500] {{webarchive |url=https://web.archive.org/web/20130314102344/http://www.amiga-hardware.com/showhardware.cgi?HARDID=6 |date=March 14, 2013 }}</ref>

===Amiga 2500 {{anchor|amiga2500}}===
{{Infobox computer
| Photo = 
| Name = Amiga 2500
| Type = [[Personal computer]]
| Released = 
| price = 
| Discontinued = 
| Processor = {{nowrap|[[Motorola 68020]]}} {{nowrap|@ 14.3&nbsp;MHz}} <br>  {{nowrap|[[Motorola 68030]]}} {{nowrap|@ 25&nbsp;MHz}}
| Memory = 1 [[megabyte|MB]]
| OS = 
| predecessor = 
| successor = 
| units sold = 
}}

The '''Amiga 2500''', also known as the '''A2500''', similar to the A1500 is not a distinct model, but simply a marketing name for an Amiga 2000 with a different base configuration. The configuration of an A2500 included a 14.3&nbsp;MHz [[Motorola 68020]] or 25&nbsp;MHz [[Motorola 68030|68030]]-based accelerator card.<ref name="Amiga2000">{{cite web | title=Amiga 2000 | url=http://www.old-computers.com/MUSEUM/computer.asp?c=63 | year=2005 | access-date=December 26, 2009 | archive-url=https://web.archive.org/web/20160305073601/http://www.old-computers.com/MUSEUM/computer.asp?c=63 | archive-date=March 5, 2016 | url-status=dead }}</ref> 68020 versions were referred to as '''A2500/20''', and 68030 versions as '''A2500/30'''.<ref name="Amiga2500/30">{{cite web | title=Amiga 2500/30 |url=http://www.amiga4ever.nl/systems.php?id=25| year=2004 |access-date=December 26, 2009| archive-url= https://web.archive.org/web/20100130090654/http://www.amiga4ever.nl/systems.php?id=25| archive-date= January 30, 2010 | url-status= live}}</ref> The accelerator cards used by the A2500 (the A2620 and A2630) were also available separately as upgrades for the A2000. The A2620 included a [[Motorola 68881]] FPU and [[Motorola 68851]] MMU, whereas the A2630 included a [[Motorola 68882]] FPU (and MMU built into the 68030).

Because the A2500 has a [[Motorola 68000]] on the motherboard that goes unused, the design is not very cost-effective. A project to replace it with a 68020 on-board began, intending to be a Zorro-II-based 68020 machine, but the project eventually became the Amiga 3000 when [[Dave Haynie]] sought to include his new Zorro-III bus.

The A2500 remained in production after the release of the A3000, primarily because the original [[Video Toaster]] will not fit in an unmodified A3000 case. Until the release of the [[Video Toaster|Video Toaster 4000]], the A2500 was the fastest computer available for use with the Toaster.

A further variant called the A2500UX was also available which was supplied with [[Amiga Unix]] and a tape drive.<ref>{{cite web|url=http://www.bigbookofamigahardware.com/bboah/product.aspx?id=20| title=A2500 - Commodore| website=Big Book of Amiga Hardware}}</ref>