Emulation on the Amiga

The Amiga computer can be used to emulate several other computer platforms, including legacy platforms such as the Commodore 64, and its contemporary rivals such as the IBM PC and the Apple Macintosh.

MS-DOS on Amiga via Sidecar or Bridgeboard

MS-DOS compatibility was a major issue during the early years of the Amiga's lifespan in order to promote the machine as a serious business machine. In order to run the MS-DOS operating system, Commodore released the Sidecar for the Amiga 1000, basically a 8088 board in a closed case that connected to the side of the Amiga. Clever programming (a library named Janus, after the two-faced Roman god of doorways) made it possible to run PC software in an Amiga window without use of emulation. At the introduction of the Sidecar the crowd was stunned to see the MS-DOS version of "Microsoft Flight Simulator" running at full speed in an Amiga window on the Workbench.

Later the Sidecar was implemented on an expansion card named " [http://bridgeboard.infologist.com Bridgeboard] " for Amiga 2000+ models. Bridgeboard cards appeared up to 486 processor variants. The Bridgeboard card and the Janus library made the use of PC expansion cards and harddisk/floppydisk drives possible. The bridgeboard card was manufactured by Commodore, later third party cards also appeared for the A500/1200 expansion slot such as the KCS Powerboard.

Eventually, full-software emulators, such as PC-Task and PCx allowed Amigas to run MS-DOS programs, including Microsoft Windows, without additional hardware, at the costs of speed and compatibility.

Amiga Transformer

Early Amigas could use a program called Transformer to emulate a PC via software, however it was extremely slow; The 'Landmark' benchmark rated it as a 300 kHz 286, far slower then the 4.7 MHz of IBM's oldest and slowest PC. In addition, it would only run on Amigas using the 68000 microprocessor, and would not run if the Amiga had more than 512K of RAM.

PCTask

PCTask is a software PC emulator emulating PC Intel hardware with 8088 processor and CGA graphic modes.The latest version of it (4.4) was capable to emulate a 80486 clocked at 14 MHz and features include support for up to 16 MiB RAM (15 MB extended) under MS-DOS, up to two floppy drives and 2 hard drives. The emulator could make use of hardfile devices and then it could handle multiple hard disk files and hard disk partitions. It supported high Density floppies and CD-ROM if the Amiga hardware had mounted those devices.

The graphics mode available were MDA, CGA, EGA, VGA and SVGA emulating Hercules graphic cards with 512 KiB to 2 MiB RAM, and up to 256 colors on Amiga AGA machines, and could make use of Amiga graphic boards (e.g. Cybergraphics, EGS Spectrum, Picasso).

Parallel, Serial and PC speaker emulation, and mouse support, including serial mouse emulation were also granted.

If the Amiga hardware is fast enough (68060 or PPC) and has enough RAM, there could be also the possibility to run multiple PC-Task processes on the same machine, run MS-DOS applications in a Amiga window on a public screen (e.g. on Amiga Workbench GUI).

PCTask could also transfer files between Amiga side and the emulated MS-DOS machine; it could make use of GoldenGate bridge cards which allow the Amiga equipped with expansion slots to get complete control of its silent ISA slots and use PC-ISA cards. And it could run even, MS Windows up to 3.11.

PcTask has a 8088/80286/80486 JITM (Just in Time Machine) capable to map all instructions of these processors, but require 4 megabytes extra of RAM for activating this feature.

Mac OS on Amiga

Also introduced for the Amiga were two products, A-Max (both internal and external models) and the Emplant expansion card. Both allowed the Amiga to emulate an Apple Macintosh and run the Macintosh Operating System. It required an Apple Macintosh ROM image, or actual ROMs in the case of A-Max, which needed to be obtained from a real Macintosh. The user needed to own the real Macintosh or Mac ROMs to legally run the emulator.

In 1988 the first Apple Mac emulator, A-Max, was released as an external device for any Amiga. It needed Mac ROMs to function, and could read Mac disks when used with a Mac floppy drive (Amiga floppy drives are unable to read Mac disks. Unlike Amiga disks Mac floppy disks spin at variable speeds, much like CD-ROM drives). It wasn't a particularly elegant solution, but it did provide an affordable and usable Mac experience.

ReadySoft, makers of A-Max, followed up with A-Max II in the early 1990s. A-Max II was contained on a Zorro-compatible card and allowed the user, again using actual Mac ROMs, to emulate a color Macintosh. In fact, an Amiga 3000 emulating a Mac via A-Max II was significantly faster than the first consumer color Mac, the LC.

Over time full-software virtualization was available, but you still had to get a ROM image. Example virtualizators include ShapeShifter (not to be confused with the third party preference pane ShapeShifter), later superseded by Basilisk II (both by the same programmer who conceived SheepShaver, Christian Bauer), Fusion and iFusion (the latter ran classic Mac OS by using a PowerPC "coprocessor" accelerator card).

This form emulation creating a Virtual Machine has been said to equal or better the speed of a Macintosh with the same processor, especially with respect to the m68k series due to real Macs running in MMU trap mode, hampering performance. Moreover, in the period when no new 68k Mac models were being developed and the majority of Mac software was not natively available on PowerPC Macintosh yet (but only runnable through a slow 68k emulation), the fastest "Macintosh" machines around were actually by far Amiga computers with 68060 CPUs running ShapeShifter or Fusion.

One should note that although Amigas were very successful at emulating Macintoshes, it was never considered to be a Macintosh clone as it could not use Mac OS as a primary operating system.

Modern Amigas like AmigaONE and Pegasos can emulate Macintosh Machines either by using Basilisk II emulator or by running an Amiga emulator in its turn running any software based Amiga Classic Macintosh emulator (such as Fusion), or even using MacOnLinux emulators.

C64 and other retrocomputing Commodore machines

Various C64 emulators were produced for the Amiga. Noteworthy were Go64 and A64.

Both Classic and modern Amigas have their own version of Frodo and VICE software emulators.

VICE can emulate almost all 8-bit machines made by Commodore, including C64, C128, and PET.

Atari

Atari emulation on Amiga is very easy because the two machine share the same model of processor (68000) and more or less feature the same hardware characteristics.

In the past there were produced various software based Atari emulators for trhe Amiga such as Amtari, or Medusa emulator.

Modern Amiga-like platforms such as Pegasos equipped with MorphOS operating system, emulates Atari ST and Atari STE platforms with Hatari open source emulator released under GPL.

ignetics-based Machines

The Amiga is one of only two platforms with a dedicated emulator of Signetics-based systems, namely, the Emerson Arcadia 2001, the Interton VC 4000, and the Elektor TV Games Computer.

Amiga emulation

Classic Amiga Machines acclerated with PPC processor expansion cards, or modern Amigas like AmigaONe or Pegasos could even emulate old Amiga Hardware by using their version of UAE (Ubiquitous Amiga Emulator).