Acorn Archimedes Emulator

Change Log

ArcEm 1.50.1 – 18th December 2015
  • This is just a maintenance release for the RISC OS version of ArcEm. There are only two notable changes compared to 1.50:
    • The released binary has been compiled with GCC 4.7.4, eliminating a null pointer deference bug that was present with the previous version of GCC/UnixLib
    • Support has been added for the new screen modes introduced with RISC OS 5.21 (e.g. 64k colour modes and red/blue swapped modes), improving compatibility with new machines
ArcEm 1.50 – 16th December 2012
  • New features
    • Addition of ports to Amiga OS 3 and OS 4.
    • Sound emulation.
    • Support for RAM sizes other than 4MB (512KB, 1MB, 2MB, 4MB, 8MB, 12MB & 16MB now supported).
    • ARM250 & ARM3 CPU emulation.
    • ArcEm clock set from host's clock, partial RTC support.
    • Extension ROM emulation, allowing support for the following new features when emulation RISC OS:
      • HostFS - A RISC OS filesystem to allow use of a directory on the Host Filing system as a virtual hard drive.
      • Mouse scroll wheel support.
      • Extra video modes, up to 1024x768 in 16 colours and 800x600 in 256 colours.
  • Bug fixes/Improvements
    • Many performance tweaks and optimisations, resulting in a 5-6 times performance gain on ARM hosts. A 600MHz XScale can now achieve a level of performance roughly equivalent to an 8MHz ARM2. Similar performance gains can be seen on other low-power hosts.
    • Video emulation rewritten to provide accurate redraw and VSync timing, down to the scanline level.
    • Video emulation now supports upscaling and aspect ratio correction for rectangular pixel modes.
    • All hardware clocks/timers (IOC timers, video DMA, audio DMA, etc.) now run in real time, ensuring one second takes one second no matter how fast the host machine is.
    • Source code tidied a bit to remove redundant code, including support for emulation of 32bit processor modes (there are other, much better emulators for that!).
    • Source code converted to use C99 number types to aid portability.
    • Instruction prefetch now correctly emulated - ensures correct operation with self-modifying code and some forms of copy protection.
    • RISC OS version now 32bit compatible, and ARMv7-safe. Also much more useable with modern machines/LCD monitors as it no longer requires the host to be able to support Archimedes screen modes.
    • Windows version updated to build under Visual Studio 2010 (including Express edition).
    • Unix/X11 version now supports X servers that don't support XWarpPointer.
ArcEm 1.00 – 6th May 2002
  • New manual and new SourceForge page. Other documentation deprecated.
  • Added project files for MS VC++, and fix warnings provoked by it.
  • Further split of windowing/non-windowing functionality to aid division of architecture-independent files.
  • Windows version made independent from Cygwin.
  • Windows support imported from eQRD version. Features brought inline with other versions, including icon change, and same format for choices file.
  • Entirety of build warnings fixed under GCC, including those that appeared from turning on harsh warning flags.
  • General tidying.
  • Makefile rearranged so that default Unix builds are more sensible.
ArcEm 0.60 – 30th September 2001
  • Support for running RISC OS, by Alex Macfarlane Smith and Peter Naulls
  • Split of the windowing code, to allow independent development.
  • Some small speed ups.
  • Source code tidying and warning fixes.