Emulated hardware devices in Microsoft Virtual Server 2005


This article describes the emulated hardware devices in Microsoft Virtual Server 2005.

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Virtual Server 2005 emulates an American Megatrends Inc. (AMI) basic input/output system (BIOS) using the Intel 440BX with the PIIX4 chipset and the following on-board components:
  • Complementary metal oxide semiconductor (CMOS)
  • Real-time clock
  • Random access memory (RAM) and video RAM (VRAM)
  • Memory controller
  • Direct memory access (DMA) controller
  • Peripheral Component Interconnect (PCI) bus
  • ISA bus
  • System Management (SM) bus
  • Power management
  • 8259 programmable interrupt controller (PIC)
  • Programmable interrupt timer (PIT)

Floppy disk drives

Virtual Server 2005 emulates floppy disk drive support for floppy disk drives of up to 1.44 megabytes (MB). Virtual Server 2005 also supports mapping to real floppy disk drives or to floppy drive images.

Serial ports (COM ports)

Virtual Server 2005 emulates two serial ports. These ports can be mapped to the host computer's serial ports.

Note You can only map to the standard COM 1 to COM 4 physical serial ports. Additionally, you can do this only if the ports are using standard I/O address ranges. Therefore, many add-on serial cards do not work with Virtual Server. However, older ISA cards that contain jumper switches may work.

Printer port (LPT port)

Virtual Server 2005 emulates a single printer port that maps to the host computer's parallel port.

Note You can only map to the LPT1 physical parallel port. Additionally, you can do this only if the port is using the standard I/O address range of 378h to 37Fh. Therefore, add-on parallel cards are not supported in Virtual Server 2005.


Virtual Server 2005 emulates a standard PS/2 Microsoft IntelliMouse device that can be mapped to either a PS/2 mouse or to a USB mouse on the host computer.


Virtual Server 2005 emulates a standard PS/2 101-key Microsoft keyboard that can be mapped to either a PS/2 keyboard or to a USB keyboard on the host computer.

Ethernet controller

Virtual Server 2005 emulates a multi-port Digital Equipment Corporation (DEC) 21140 10/100TX 100 megabit Ethernet network adapter with one to four network connections, multiplexed on a single Virtual Server slot. An unlimited number of virtual networks are supported. All supported versions of the Windows operating system include drivers for the DEC 21140 network card.

Note To obtain MS-DOS drivers for the DEC 21140 network card, visit the following Intel Web site:Note The DEC 21140 network card may appear on the virtual machine as "Intel 21140." These are equivalent network adapters.


A virtual computer uses the CPU of the physical computer. Therefore a virtual machine has the same type of CPU as the physical computer where Virtual Server 2005 is installed. Although Virtual Server runs on systems that have up to 32 processors, guest operating systems only see a single CPU for each virtual machine. Virtual Server is optimized for industry standard hardware that has up to eight CPUs.


Virtual Server 2005 supports up to 64 gigabytes (GB) of RAM on the host computer and up to 3.6 GB for each virtual machine. Highly scalable systems can only support very large memory configurations if PAE (Physical Addressing Extensions) and AWE (Advanced Windowing Extensions) are installed on the host operating system.

Video card

Virtual Server 2005 emulates the S3 Trio64 graphics adapter with 4 MB of VRAM, Visual Electronics Standards Association (VESA) 2.0 compliant VGA and SVGA support, and support for DirectX.

Note Before a virtual machine can recognize every available resolution, you must install the virtual machine additions.

Integrated device electronics (IDE)/ATAPI storage

Virtual Server 2005 emulates up to 4 IDE devices, such as hard drives, CD drives, DVD-ROM drives, or ISO images. Additionally, Virtual Server 2005 emulates virtual disk images of up to 128 GB per IDE channel.

Note IDE is limited to one transaction per bus, whether it is a physical IDE device or a virtual IDE device. If you have two IDE disks attached to the same virtual or physical IDE bus, you are limited to a single transaction for both devices.

Small computer system interface (SCSI) storage

Virtual Server 2005 emulates the Adaptec 7870 SCSI controller chip set. This chip set has up to four virtual SCSI adapters. Each SCSI hard disk can be up to two terabytes. Each virtual SCSI adapter can support up to seven virtual SCSI hard drives. Therefore, the total direct-connect storage capacity is over 56 terabytes per virtual machine. Virtual Server supports simple active or passive clustering between virtual machines.

Note SCSI controllers and disks support multiple, concurrent input/output (I/O) to increase the performance of both physical SCSI devices and virtual SCSI devices. We recommend that you use SCSI whenever you can.

Sound card

Virtual Server 2005 does not include an emulated sound card.