You must have heard about VMWare or Virtual PC; now, I will introduce you to Bochs. This is an open-source PC emulator written in C++. It can host different types of platforms based on different architectures. It is released under GPL license.
This PC Emulator, not unlike others, emulates an Intel X86 computer, common I/O devices and BIOS. Bochs can be compiled for the emulation of a 386, 486, or Pentium CPU, either X86 or 64, including additional instructions for MMX, SSEx and 3Dnow!.
It can be run in different operating systems, such as Linux, DOS, or Windows (Vista and Windows 7 included, according to my tests). This software is mostly used for keeping the host operating system clean when you need to use some unreliable (or incompatible) software: when the virtual operating system fails, the host doesn’t. The program also emulates every single hardware part of a computer, such as hard drives, cdrom, and floppy drives (Bochs even allows you to add hardware if the emulation is already running).
However, it also should be noted that the emulation performance is somewhat slower than in other emulators. In addition, unlike other emulators, Bochs provides a much less intuitive GUI. Still, if you only need to run old games that refuse to run in your current operating system, Bochs could be your choice.
v2.4 [May 6, 2009]
Changes in 2.4.2 (November 12, 2009):
- CPU and internal debugger
- VMX: Implemented TPR shadow VMEXIT
- Bugfixes for CPU emulation correctness (mostly for VMX support).
- Bugfixes and updates for Bochs internal debugger
- On SMP system stepN command now affects only current processor
- Memory
- Bugfixes for > 32-bit physical address space.
- Allow to emulate more physical memory than host actually could or would
like to allocate. For more details look for new .bochsrc 'memory' option.
- Cleanup configure options
- All paging related options now will be automatically determined according
to --enable-cpu-level option. Related configure options
--enable-global-pages, --enable-large-pages,
--enable-pae, --enable-mtrr
are deprecated now. Only 1G paging option still remaining unchanged.
- Deprecate --enable-daz configure option. Denormals-are-zeros MXCSR control
will be enabled automatically iff SSE2 is supported (like in hardware).
- Deprecate --enable-vme configure option, now it will be supported iff
CPU_LEVEL >= 5 (like in hardware).
- I/O Devices
- Bugfixes for 8254 PIT, VGA, Cirrus-Logic SVGA, USB UCHI
- SF patches applied
[2817840] Make old_callback static by Mark Marshall
[2874004] fix for VMWRITE instruction by Roberto Paleari
[2873999] fix CS segment type during fast syscall invocation by Roberto Paleari
[2864389] Debugger gui maximize on startup by Thomas Nilsen
[2817868] Rework loops in the memory code by Mark Marshall
[2812948] PIT bug by Derek
