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Old 14 September 2011, 10:08   #25
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This AMOS for Windows install uses Bernd Meyer's Just-In-Time (JIT) compiler for extra speed. This is needed as the included AROS-68k ROM beta is still quite slow. JIT compilation involves translating whole blocks of machine code WHILE RUNNING from one instruction set (Amiga 680x0) to another (PC x86). It even works with the AMOSPro Compiler, and AMOSPro's compiled AMAL and Interface scripts, translating them all into x86 machine code.
The resulting emulated 680x0 CPU gives Pentium 1-level performance on an Intel Atom netbook, Pentium 2-level performance on a Core2Duo, and Pentium 3-level performance on an i7. Needless to say, AMOS has never run natively on such a fast platform. It also uses immediate Blitter emulation for faster graphical performance. A few included AMOS games will need to be modified to be playable on such a fast CPU (try adding "Wait Vbl").
Unfortunately the JIT compiler is not currently compatible with Vsync (e.g. smooth scrolling). You will still need a real Kickstart ROM (such as by purchasing Amiga Forever 2012) to use AMOS under emulation with smooth scrolling. This AMOS for Windows build currently only works with AROS-68k ROM, but will be updated soon to support a "drop-in" ROM for extra performance and compatibility.

As well as various (limited) mobile ports of UAE, there is also the PUAE Amiga emulator for non-Windows platforms, which is currently in development and includes the latest features from WinUAE. A stable version working with AROS ROM would make an out-of-the-box Linux and Mac OS X install of AMOS possible, with the possibility of including future WinUAE updates such as improved Vsync. (It still needs a bit of work though, but is very promising).

PUAE has also been ported to non-x86 platforms such as ARM platforms (including Linux and Android), however does not feature JIT except on Intel/AMD x86. To get good performance of AMOS on an ARM mobile device in the absence of JIT would thus require a real Kickstart ROM (still under copyright), until a UAE-compatible 680x0-to-ARM JIT-compiler is implemented. If that is done, that would make fast, legal and free out-of-the-box AMOS available in your pocket.

There is also AROS-x86, a free clone of AmigaOS for modern PCs (particularly its "Icaros Desktop" and "Broadway" distributions). This includes a port of the UAE Amiga Emulator called Janus-UAE, which includes special integration features, and has been reported working with AROS-68k. So on this OS, you can launch AMOS from its original Amiga icon on a PC, and it will seamlessly launch. (PUAE on AROS may also be a possibility, and a possible merge with Janus-UAE.) AROS already has a Linux-hosted ARM version, with the possibility of one day working as a native OS on ARM, incorporating integrated classical Amiga emulation. This would be another excellent platform for AMOS (especially when/if JIT compilation comes to that platform).

Finally, WinUAE and PUAE feature retargetable graphics, or RTG. This allows emulation of a 24-bit graphics card, and supports native desktop resolutions on a PC. This is not available in AMOS, which is limited to the original Amiga chipset, however there is nothing preventing some AMOS enthusiast from writing an RTG extension, allowing AMOS to work with fast true-colour graphics in future...

Who says AMOS is dead?

Last edited by Adgarharrison; 13 June 2012 at 15:16.
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