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"VAXen were tough, but age catches us all. Our emulators keep VAX applications ticking."

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VAX Replacement

Migration Specialties provides virtual VAX solutions to replace DEC VAX hardware. Replacing a legacy VAX system with a virtual VAX is like upgrading hardware in place. You benefit from modern hardware while retaining important legacy applications intact.

Virtual VAX Bonus

Along with the benefits of replacing legacy VAX hardware, a virtual VAX provides many new possiblities. Remote hosting, portability, multiple test-beds, training environments, backup snapshots, and more all become options with virtual VAX hardware that were simply impossible with ageing physical equipment.

VAX Virtualization Advantages

  • Virtual OpenVMS environment.
  • Quick deployment: Three to five day implementation.
  • Modern hardware: Improves reliability, performance & energy efficiency.
  • More Space: Easily enlarge existing disks and add more disks.
  • VM's: Supported on VMware®, Sun VirtualBox, Apple Boot Camp & others.
  • Allows mutliple copies on a single host.
  • Lower operating costs with a smaller data center footprint.
  • Binary compatibility: Application source code not required.
  • Improved integration with Microsoft Windows.
  • High ROI: Preservation of investment in software & vested employee knowledge.
  • No change in operation or user environments.
  • Supported by HP.

Virtualization Solutions for VAX

Migration Specialties utilized the open source SimH VAX to upgrade legacy VAX hardware. This solution replaces the underlying VAX CPU, memory, and mass storage devices with virtual equivalents while maintaining binary compatibility with VAX O/S's and layered products. SimH VAX can be deployed on Windows and Linux-based servers.

SimH VAX runs as a 32-bit application. Standard peripherals such as serial ports, disk drives, and CD-ROM drives are emulated or mapped to equivalent host hardware. For example, RD54 disk drives can be emulated as container files, a CD-ROM can be mapped to the host's CD-ROM drive, and serial ports can be mapped to network ports.

Each emulator is binary compatible with the VAX O/S and layered product software. No modification, translation, or recompilation of code is necessary. An image of each VAX disk is transferred to the emulated system, where the code executes as it would on the physical VAX. The emulator runs as a single application within the Windows environment.


SimH is an open source application. Migration Specialties materially participates in its ongoing development. SimH supports a limited set of VAX processors. It is a suitable VAX replacement when performance is not critical. Additional SimH information is available at

Porting to a VAX Emulator

Porting applications to a VAX emulator is similar to porting them to a new physical VAX system. The emulator installation is first configured to look like the VAX system it is replacing. The O/S, software applications, and data are then copied to the emulated VAX system. With the O/S and applications in place, the emulated VAX is ready to boot and run.

VAX emulators create a virtual VAX environment within the context of the host O/S. The VAX operating environment is indistinguishable from the legacy VAX being replaced.

Turnkey Solutions

Trouble-free VAX emulation installations require correct initial configuration of the product. Configuration is a one-time process that requires knowledge and experience in VAX hardware and its mapping within the emulated VAX environment. We offer turnkey installation as part of our VAX replacement solutions to make configuration quick and easy. Turnkey services include system construction, software porting, and onsite installation. More information is available on our Emulator Services page.

Obtaining a Quote

Before we can quote a VAX emulation replacement solution, you will need to provide us with information concerning your VAX environment. This can be accomplished by running the DCL procedure VMS_INFO.COM and sending us the results. You may optionally request a brief which we will e-mail to you. Both the procedure and the questionnaire cover your VAX hardware configuration and operating environment. Neither seeks any proprietary information or application data. One or the other must be completed before we will quote a replacement system.
  • VMS_INFO.COM system configuration reporting procedure.
  • Request a .
If you would like additional information about a VAX upgrade via virtualization give us a call or . See our OpenVMS page for Migration Specialties OpenVMS services and our Porting page for other VAX replacement options.

VAX History

Digital Equipment Corporation introduced the VAX series of computers in 1977. The series was produced for 23 years, with the final hardware orders taken in 1999. VAX systems ranged from desktop workstations to mainframes. The system was offered with two main operating systems, VMS and Ultrix, which were supported across the entire range of VAX platforms. VAX systems were well received and deployed in a broad range of environments.

VAX systems were supplanted by Alpha systems in the mid-1990's. Alpha systems are, in turn, being supplanted by Itanium-based Integrity systems today. Compaq Computer obtained the VAX and Alpha product lines when it purchased Digital Equipment Corporation in 1998. Compaq's subsequent merger with HP in 2002 left the VAX legacy in the hands of Digital's former competitor, HP.

VMS, which suffered a name change to OpenVMS in 1992, remains in production to this day, offered on HP's Itanium-based Integrity servers. The operating system is renowned for its reliability, security, and clustering capabilities - all good reasons to retain its functionality with virtual VAX solution. See our OpenVMS page for Migration Specialties OpenVMS services.

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