The Machine page contains settings related to the emulated machine as a whole, such as the machine type, CPU type and amount of memory.
Machine type / Machine
Machine/motherboard model to emulate. The Machine box lists all available models for the machine class selected on the Machine type box.
The Configure button opens a new window with settings specific to the machine, such as BIOS type selection.
Settings for the machine’s onboard devices have been moved to the Configure buttons at the devices’ respective locations; for instance, configuring the amount of installed video memory for an onboard video chip is now done through the Configure button next to the Display page’s Video box when the Internal option is selected there.
CPU type / Speed
Main processor to emulate. The Speed box lists all available speed grades for the processor family selected on the CPU type box. These boxes only list processor types and speed grades supported by the machine selected above.
Math co-processor to emulate. This box is not available if the processor selected above has an integrated co-processor or lacks support for an external one.
Number of memory wait states to use on a 286- or 386-class processor. This box is not available if any other processor family is selected above.
Programmable Interval Timer emulation mode. Auto should cover most use cases, automatically selecting Fast mode on 486-class and newer processors or Slow mode on older ones. A limited set of timing-sensitive applications require Slow mode, which is slower but more accurate.
Amount of RAM to give the emulated machine. The minimum and maximum allowed amounts of RAM will vary depending on the machine selected above.
Enable the dynamic recompiler, which provides faster but less accurate CPU emulation. The recompiler is available as an option for 486-class processors, and is mandatory starting with the Pentium.
Enable a slower but more accurate math co-processor emulation, for running a limited set of operating systems and applications which demand full 80-bit precision from the floating point unit.
Automatically copy your host system’s date and time over to the emulated machine’s hardware real-time clock. Synchronization is performed every time the emulated operating system reads the hardware clock to calibrate its own internal clock, which usually happens once on every boot.
Disabled: do not perform time synchronization. The emulated machine’s date and time can be set through its operating system or BIOS setup utility. Time only ticks while the emulated machine is running.
Enabled (local time): synchronize the time in your host system’s configured timezone. Use this option when emulating an operating system which stores local time in the hardware clock, such as DOS or Windows.
Enabled (UTC): synchronize the time in Coordinated Universal Time (UTC). Use this option when emulating an operating system which stores UTC time in the hardware clock, such as Linux.