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VAX Hardware
To run OpenVMS VAX as a hobbyist, you will need hardware, or a hardware emulator. The most common VAX choices among hobbyists are the VAX workstations, known as VAXstation series systems. VAXstation series systems are available in numerous models. More recently, VAX hardware emulators are also available.
Free hobbyist licenses are available for OpenVMS VAX.
VAXstation Series
The VAX and the VAXstation series are among the oldest systems that will bootstrap OpenVMS, and provide thirty-two (32) bit virtual addressing, and various and implementation-dependent number of physical addressing capabilities. With all VAX systems and particularly with the VAXstation series systems most commonly of interest to hobbyists, you will have 32-bit addressing, and the key considerations when acquiring hardware are the physical and electrical requirements, the console capabilities, and the relative performance of the systems.
VAXstation systems are configured as workstation systems and generally include a graphics controller. VAX and MicroVAX series systems are configured as time-sharing or server systems. Older VAX systems and (when originally sold) top-end systems generally do not provide native SCSI support. Newer VAXstation series systems and newer MicroVAX systems do provide SCSI capabilities.
VAXstation 4000 Series
Of the entire VAXstation series, the VAXstation 4000 series and particularly the VAXstation 4000 Model 60 and Model 9x, are the typically the best and fastest choices among VAX workstations.
These systems feature system enclosures sized similar to those of a tower-sized PC, and provide integrated 10 megabit networking and SCSI support. All VAXstation 4000 series systems were sold with graphics controllers, though it is possible to remove the graphics adapter on certain models. (Check before you buy.)
The VAXstation 4000 model VLC is the slowest member of the family and with more limited physical memory and expansion capabilities. The VAXstation 4000 VLC is, however, among the smallest and most portable VAXstation systems built.
VAXstation 3100 Series
The VAXstation 3100 series is also commonly available, and provides SCSI and graphics support.
Older and generally slower than the VAXstation 4000 series, the VAXstation 3100 series implements the six-byte SCSI command set that was current at the time the console was designed, and this implementation limits the maximum addressable capacity of the system disk to slightly more than one gigabyte (1.06GB) in capacity; you cannot reliably bootstrap from or operate with system disks larger than one gigabyte, nor can OpenVMS reliably crash on such disks.
OpenVMS VAX system crashes use the bootstrap drivers, and you really don't want the system crash dump I/O to wrap at its addressing limit and continue writing the blocks of the crash dump starting at the lowest blocks of the disk. This address-wrapping has the unpleasant side-affect of overwriting whatever happens to be in those low blocks. If you want to risk this anyway including ensuring the SYSDUMP.DMP file doesn't move during defragmentation, restorations, AUTOGENs or upgrades, make sure the entire dump file is always located below the console addressing limit. (Best to always use a smaller system disk, or to avoid the six-byte VAX consoles, or to use LD logical disk driver or such to set aside the entire upper part of the disk above the six-byte limit.)
Though less desirable and less flexible than the VAXstation 4000 series, these systems are quite reasonable choices for hobbyists seeing VAX hardware.
Details on the system disk limits are discussed in the OpenVMS FAQ.
VAXstation 3200 and 3500
Older members of the VAXstation series systems including the VAXstation 3200 and VAXstation 3500. These are Q-bus systems, and somewhat physically larger than VAXstation 3100 and VAXstation 4000 series.
Q-bus systems provide reasonable expansion capabilities, but tend to lack native SCSI support. Q-bus controllers are (or were) available for various functions. The oldest members of this series are the VAXstation I and VAXstation II, and the seldom seen VAXstation III and VAXstation IV series. These are also Q-bus systems, with similar limitations and considerations.
The VAXstation I and VAXstation II are not particularly recommended, centrally as these are very slow systems, and Q-bus systems in general are not immediately suitable for new OpenVMS Hobbyists.
Other VAXstation Series
The VAXstation 3520 and VAXstation 3540 series are rare boxes, and are workstations that are capable of symmetric multiprocessing (SMP). These (and the even more rarely-seen VAXstation 8000 series) are the only VAX workstation systems capable of SMP. The VAXstation 3520 and VAXstation 3540 are dual- and quad-processor systems based on the Mbus I/O bus, VCB03 series graphics, and with optional and (very) limited Q-bus expansion. (Only a few modules were reportedly supported by the particular Q-bus adapter optionally configured on the VAXstation 3520 and VAXstation 3540 series.)
The VAXstation 8000 is a VAXBI (BI; Bus Interconnect) bus system with specialized Evans and Sutherland (Shadowfax) graphics, and is most closely related to the VAX 8200 series.
MicroVAX and VAX 4000 series
MicroVAX series in the 3100 series are generally good choices, and particularly MicroVAX 3100 Model 30 and higher. The VAX 4000 model 10x series is also a good choice.
The MicroVAX 3100 models 10 and 20, and the older boot ROMs found on the MicroVAX models 10e and 20e series share the same gigabyte system disk limits of the VAXstation 3100 series. The MicroVAX 3100 model 30 and higher are newer and (as the model numbers increase) generally faster, and can bootstrap from larger SCSI system disks.
The MicroVAX 3500, MicroVAX 3600, MicroVAX 3800, VAX 4000 (model 200 and up), the rarely seen VAX 4000 model 50 series, and such are Q-bus systems, with the MicroVAX I and MicroVAX II being (yet) older and (yet) slower members of the series. Various Q-bus enclosures are configured, with the BA23, BA123, BA213, BA215, and BA400 series being common choices.
Q-bus VAX 4000, MicroVAX and VAXstation systems are reasonable choices for OpenVMS Hobbyists with OpenVMS system management experience, and particularly for folks with Q-bus hardware configuration experience. Conversely, these systems are more difficult to manage and configure when compared to other systems available to new OpenVMS Hobbyists.
Before you acquire one of these Q-bus systems, ensure you can obtain the Q-bus documentation for all Q-bus controllers, and you are familiar with the serpentine configuration requirements, and how to establish with CSR and interrupt vector mechanisms. You will also want to acquire source(s) for Q-bus controllers and for the associated storage devices. Very few and very limited SCSI controller options exist for the Q-bus. If the terminology used in this paragraph is unfamiliar to you, you will want to become familiar with it, and you will also want to consider another of the other available systems.
VAX
The VAX series systems are generally the largest of VAX systems, with three broad generations of the hardware.
The oldest generation is the VAX-11 series (and arguably the oldest of the VAX 8000 series, the VAX 8600 and VAX 8650 -- these were originally to be known as the VAX-11/790 series).
The middle VAX series is the VAX 8000 series including the VAX 8200, VAX 8250, VAX 8300, VAX 8350, and VAXstation 8000, various derivatives and relatives of the VAX 8800 series including the VAX 8500, VAX 8530, VAX 8550, VAX 8700, VAX 8810, VAX 8820, VAX 8820N, VAX 8830, VAX 8840, VAX 8974, VAX 8978 series. The so-called mainframe VAX 9000 series systems also fit here.
The most recent VAX generations include the VAX 6000, VAX 7000, and VAX 10000 series. (The VAX 4000 is discussed above.)
These same three general generations are also roughly those that are built using discrete hardware logic, with large-scale integration, and with microprocessor-based hardware, respectively.
In the middle and later generations, the VAXBI is often either the system bus in VAX systems, and used an I/O bus in other systems.
VAX systems are also among the largest and heaviest of systems, with weights often (well) in excess of 250 kilograms, and with power and cooling requirements to match. (On the topic of enclosure size and of cooling, there are a few hobbyists who have refurbished and retargeted VAX systems.)
VAX systems generally do not include SCSI support, nor graphics capabilities.
Rule of thumb: if the box has VAXBI as part of the configuration or as an optional component, it's going to be a moderate to large box. The VAX 8200, 8250, 8300, 8350 (and the cousin, the VAXstation 8000 series, discussed earlier) are the smallest, and these boxes are not particularly small. XMI (Extended Memory Interconnect) boxes are larger; boxes that use XMI as the system bus or I/O bus are all large.
Fairly few hobbyists own VAX systems. (Most own MicroVAX-class systems, or VAX 4000 series, or VAXstation series, or will use hardware emulation.) .
VAX Emulation
Commercial and non-commercial VAX hardware emulators are available, allowing OpenVMS VAX to bootstrap and operate as a guest of another operating system. As far as OpenVMS VAX itself is concerned, an emulated system looks, operates, bootstraps and is licensed similar to a physical VAX, VAXstation or MicroVAX series system, depending on the particular hardware emulated.
For hobbyists lacking hardware for any of various reasons, VAX emulators are a good choice. VAX emulators can also have higher performance than many of the physical VAX systems, depending on the speed of the underlying processor and the efficiency of the emulation.
If you do choose VAX emulation, ensure that the emulation is sufficiently complete for your needs -- OpenVMS VAX itself uses comparatively little of the VAX instruction set and of the VAX architecture as compared with many applications. In other words, just because OpenVMS VAX bootstraps on the emulator does not mean that the emulation is anywhere near complete, nor that any particular VAX application code might operate correctly. Additionally, you will want to ensure the that emulator you choose operates on your target platform, and presents and emulates the I/O devices you expect to have access to on OpenVMS; if you need CD-R recording, for instance, the emulator must present that capability.
Information on hardware emulation is available.
VAX Consoles and Installation
Media
When you acquire a VAX system, you will want to plan for your OpenVMS software installation, and for your particular VAX console.
All OpenVMS hardware systems require a console of some sort, this is the equivalent of the BIOS that loads an operating system on an Intel IA-32 platform. Some older hardware systems require console-specific storage. One of the first tasks you will likely perform with the You'll also want to consider a SCSI CD device for installations and upgrades, or a SCSI CD-R/RW for installation and for interchange. console is a new OpenVMS software installation from distribution media, as this establishes a fresh, new software configuration, and (if any OpenVMS software exists on the box) this installation removes any site-specific or stale configurations.
VAX configuration with an integrated console, SCSI and a SCSI CD device are usually the easiest choice for software installation and software upgrades, while older VAX systems — particularly those lacking SCSI support — can be comparatively difficult to initially load OpenVMS VAX onto. The older VAX systems were typically installed from 9-track magnetic or TK50 tape media, from TU58 DECtape II sequential disk (random-access tape) devices, or even from 5.25 or 8 inch floppy disks, and such installation media is comparatively difficult to locate, and cannot be directly created from CD installation media. (Accordingly, new OpenVMS Hobbyists are encouraged to consider and acquire VAX systems with SCSI CD devices.)
As for the console itself, VAX systems in the VAX 8000 series and in (most of) the VAX-11/700 series configurations have a dedicated hardware console (eg: the LSI-11, or the Pro-based VAX Console processor), and dedicated console media. With these older VAX systems, you will need the console RL02 disk, the 5.25 or 8 inch floppy, the console TU58, or similar. (The VAX-11/750 and VAX-11/751 series could boot from console ROM for certain devices, but required a TU58 for bootstraps from other devices. These systems were the exception among the older VAX systems.)
More recent VAX, and all MicroVAX and VAXstation series systems have a built-in console program, and do not require console-specific console media.
VAX Rule of Thumb
The two major choices for hobbyists seeking to use OpenVMS VAX are VAX emulation, and the VAXstation 4000 series. The former for obvious reasons. The latter platform provides good speed, X Windows (DECwindows) graphics, networking, and for native SCSI support.
Failing that, members of the VAX 4000 model 10x series and of the MicroVAX 3100 series (model 30 and up) can be a good choice, but these systems lacks graphics support.
All members of the older VAXstation 3100 series and the older members of the MicroVAX 3100 series (models 10, 20 and older 10e and 20e) have a one gigabyte (1.06GB) limit on maximum SCSI boot device size; see the OpenVMS FAQ for additional details.
You'll also want to consider a SCSI configuration and a SCSI CD device for installations and upgrades, or a SCSI CD-R/RW for installation and for interchange.
No VAX hardware systems offer PCI or other buses now common in the current computing hardware enviroment, so expect to have to scrounge for I/O expansion hardware for whatever VAX system you choose. Some VAX systems have little or no bus-based expansion, other than SCSI or network. While some members of the VAXstation 4000 series do provide optional I/O expansion slots using TURBOchannel bus, you'll need to locate the TURBOchannel widgets. Other VAX systems offer Q-bus expansion. Larger VAX systems feature Unibus, MASSBUS, BI or XMI buses and adapters. Larger VAX systems also generally do not offer integrated SCSI.