|This article needs additional citations for verification. (June 2008) (Learn how and when to remove this template message)|
A64, a Commodore 64 emulator for the Commodore Amiga, was developed and published by the now-defunct software company QuesTronix, and distributed as shareware. The non-registered version was free of charge, but was limited to ten minutes of use at a time. The registered version, costing US$80, had no time limit and came with a special hardware adapter to connect a Commodore 1541 disk drive to the Amiga's parallel port.
A64 is a completely system-legal program, emulating the Commodore 64 through AmigaOS system libraries. When starting, the emulator first displays a copyright message while it loads its internal data, and then, with a click of the left mouse button, the display changes to the familiar light blue Commodore 64 screen. However, because of the differences between the Commodore 64 and Amiga keyboard layouts, and particularly with the unusual mapping Questronix used, keyboard input might take some getting used to.
A64 has some extras that a real Commodore 64 is inherently unable to provide. The most useful of these is an integrated MOS 6510 machine language monitor, which can be invoked at any time during the emulation. While in the monitor, the emulated Commodore 64 is frozen in place, giving the user full reign over its internal memory and registers. Of course, the emulator also allows machine language program input through 6510 mnemonic codes, rather than raw numeric values. Another extra feature is that the 16-colour palette of the Commodore 64 is fully customisable from the Amiga's palette of 4096 hues.
A64 supports Commodore 64 disk drives as the devices 8 through 11, just like a real Commodore 64. These drives can be either simulated, mapped onto directories on the Amiga's filesystem, or real 1541 compatible drives accessed through the hardware adapter. A64 does not support the Commodore Datasette.