"VAX" was originally an acronym for Virtual Address eXtension, both because the VAX was seen as a 32-bit extension of the older 16-bit PDP-11 and because it was (after Prime Computer) an early adopter of virtual memory to manage this larger address space. Early versions of the VAX processor implemented a "compatibility mode" that emulated many of the PDP-11's instructions, and were in fact called VAX-11 to highlight this compatibility and the fact that VAX-11 was an outgrowth of the PDP-11 family. Later versions offloaded the compatibility mode and some of the less used CISC instructions to emulation in the operating system software. The plural form of VAX is usually VAXes, but VAXen is also hear.
Operating systems
The "native" VAX operating system is DEC's VAX/VMS (renamed to OpenVMS in 1991 or 1992 when it was ported to DEC Alpha, "branded" by the X/Open consortium, and modified to comply with POSIX standards[1][citation needed]). The VAX architecture and VMS operating system were "engineered concurrently" to take maximum advantage of each other, as was the initial implementation of the VAXcluster facility. Other VAX operating systems have included various releases of BSD UNIX up to 4.3BSD, Ultrix-32 and VAXeln. More recently, NetBSD and OpenBSD support various VAX models and some work has been done on porting Linux to the VAX architecture.
The "native" VAX operating system is DEC's VAX/VMS (renamed to OpenVMS in 1991 or 1992 when it was ported to DEC Alpha, "branded" by the X/Open consortium, and modified to comply with POSIX standards[1][citation needed]). The VAX architecture and VMS operating system were "engineered concurrently" to take maximum advantage of each other, as was the initial implementation of the VAXcluster facility. Other VAX operating systems have included various releases of BSD UNIX up to 4.3BSD, Ultrix-32 and VAXeln. More recently, NetBSD and OpenBSD support various VAX models and some work has been done on porting Linux to the VAX architecture.
History
The first VAX model sold was the VAX-11/780, which was introduced on October 25, 1977 at the Digital Equipment Corporation's Annual Meeting of Shareholders[1]. The architect of this model was Bill Strecker. Many different models with different prices, performance levels, and capacities were subsequently created. VAX superminis were very popular in the early 1980s.
For a while the VAX-11/780 was used as a baseline in CPU benchmarks because its speed was about one MIPS. Ironically enough, though, the actual number of instructions executed in 1 second was about 500,000. One VAX MIPS was the speed of a VAX-11/780; a computer performing at 27 VAX MIPS would run the same program roughly 27 times as fast as the VAX-11/780. Within the Digital community the term VUP (VAX Unit of Performance) was the more common term, because MIPS do not compare well across different architectures. The related term cluster VUPs was informally used to describe the aggregate performance of a VAXcluster. The performance of the VAX-11/780 still serves as the baseline metric in the BRL-CAD Benchmark, a performance analysis suite included in the BRL-CAD solid modeling software distribution.
VAX 8350 front view with cover removed.
The VAX went through many different implementations. The original VAX was implemented in TTL and filled more than one rack for a single CPU. CPU implementations that consisted of multiple ECL gate array or macrocell array chips included the 8600, 8800 superminis and finally the 9000 mainframe class machines. CPU implementations that consisted of multiple MOSFET custom chips included the 8100 and 8200 class machines.
The MicroVAX I represented a major transition within the VAX family. At the time of its design, it was not yet possible to implement the full VAX architecture as a single VLSI chip (or even a few VLSI chips as was later done with the V-11 CPU of the VAX 8200/8300). Instead, the MicroVAX I was the first VAX implementation to move most of the complexity of the VAX instruction set into emulation software, preserving just the core instructions in hardware. This new partitioning substantially reduced the amount of microcode required and was referred to as the "MicroVAX" architecture. In the MicroVAX I, the ALU and registers were implemented as a single gate-array chip while the rest of the machine control was conventional logic.
A full VLSI (microprocessor) implementation of the MicroVAX architecture then arrived with the MicroVAX II's 78032 CPU and 78132 FPU. This was followed by the V-11, CVAX, SOC ("System On Chip", a single-chip CVAX), Rigel, Mariah and NVAX implementations. The VAX microprocessors extended the architecture to inexpensive workstations and later also supplanted the high-end VAX models. This wide range of platforms (mainframe to workstation) using one architecture was unique in the computer industry at that time.
The VAX architecture was eventually superseded by RISC technology. In 1989 DEC introduced a range of workstations based on processors from MIPS Technologies and running Ultri
x. In 1992 DEC introduced their own RISC processor, the Alpha (originally named Alpha AXP), a high performance 64-bit architecture capable of running OpenVMS.
In August 2000, Compaq announced that the remaining VAX models would be discontinued by the end of the year[2]. By 2005 all manufacturing of VAX computers had ceased, but old systems remain in widespread use.
The SRI CHARON-VAX and SIMH software-based VAX emulators remain available.
The first VAX model sold was the VAX-11/780, which was introduced on October 25, 1977 at the Digital Equipment Corporation's Annual Meeting of Shareholders[1]. The architect of this model was Bill Strecker. Many different models with different prices, performance levels, and capacities were subsequently created. VAX superminis were very popular in the early 1980s.
For a while the VAX-11/780 was used as a baseline in CPU benchmarks because its speed was about one MIPS. Ironically enough, though, the actual number of instructions executed in 1 second was about 500,000. One VAX MIPS was the speed of a VAX-11/780; a computer performing at 27 VAX MIPS would run the same program roughly 27 times as fast as the VAX-11/780. Within the Digital community the term VUP (VAX Unit of Performance) was the more common term, because MIPS do not compare well across different architectures. The related term cluster VUPs was informally used to describe the aggregate performance of a VAXcluster. The performance of the VAX-11/780 still serves as the baseline metric in the BRL-CAD Benchmark, a performance analysis suite included in the BRL-CAD solid modeling software distribution.
VAX 8350 front view with cover removed.
The VAX went through many different implementations. The original VAX was implemented in TTL and filled more than one rack for a single CPU. CPU implementations that consisted of multiple ECL gate array or macrocell array chips included the 8600, 8800 superminis and finally the 9000 mainframe class machines. CPU implementations that consisted of multiple MOSFET custom chips included the 8100 and 8200 class machines.
The MicroVAX I represented a major transition within the VAX family. At the time of its design, it was not yet possible to implement the full VAX architecture as a single VLSI chip (or even a few VLSI chips as was later done with the V-11 CPU of the VAX 8200/8300). Instead, the MicroVAX I was the first VAX implementation to move most of the complexity of the VAX instruction set into emulation software, preserving just the core instructions in hardware. This new partitioning substantially reduced the amount of microcode required and was referred to as the "MicroVAX" architecture. In the MicroVAX I, the ALU and registers were implemented as a single gate-array chip while the rest of the machine control was conventional logic.
A full VLSI (microprocessor) implementation of the MicroVAX architecture then arrived with the MicroVAX II's 78032 CPU and 78132 FPU. This was followed by the V-11, CVAX, SOC ("System On Chip", a single-chip CVAX), Rigel, Mariah and NVAX implementations. The VAX microprocessors extended the architecture to inexpensive workstations and later also supplanted the high-end VAX models. This wide range of platforms (mainframe to workstation) using one architecture was unique in the computer industry at that time.
The VAX architecture was eventually superseded by RISC technology. In 1989 DEC introduced a range of workstations based on processors from MIPS Technologies and running Ultri
x. In 1992 DEC introduced their own RISC processor, the Alpha (originally named Alpha AXP), a high performance 64-bit architecture capable of running OpenVMS.In August 2000, Compaq announced that the remaining VAX models would be discontinued by the end of the year[2]. By 2005 all manufacturing of VAX computers had ceased, but old systems remain in widespread use.
The SRI CHARON-VAX and SIMH software-based VAX emulators remain available.
A port of Linux to the VAX Architecture.
Welcome to the Linux/VAX porting project. This is a port of the Linux Kernel to the Digital Equipment Corporation (DEC) (now owned by Compaq/Hewlett Packard) VAX and MicroVAX mini computer systems. VAX (Virtual Address eXtension) computers were designed and built from the mid-1970s through to retirement of the line in 1999/2000.
Here you will find all you need to get the Linux Kernel up and running on a VAX computer. We don't support many of the models yet, and it is very early days - we don't (at the time of writing) have dynamic libraries yet! But if you have one of the systems listed in the FAQ you can run a limited version of Linux on it. See the Documentation link for details on the installation process. However, its very rough at the moment, and you need to be very comfortable with the command line and root prompt to be successful.
If you don't like the idea of that, then we suggest that you visit our friends over at the NetBSD project at http://www.netbsd.org/ who make a free UNIX that runs on a wide variety of VAX hardware. NetBSD has a much easier installation, not to mention fewer bugs (at the moment...).
Still here?
You might like to join the Mailing list if you are serious about this...
The mailing list is somewhat imaginatively titled linux-vax. To subscribe, please visit http://www.pergamentum.com/mailman/listinfo/linux-vax. This is the Mailman interface for our list. Because the list used to life on a different machine, there are currently two archives, the old one at http://solar.physics.montana.edu/hypermail/linux-vax/ and the new one, which belongs to the mailing list mentioned above at http://www.pergamentum.com/pipermail/linux-vax/. They'll be merged soon, though.
Additionally, you could subscribe to the CVS checkin mailing list for Kernel (archive), toolchain (archive) and userland tools (archive).
This project would like to acknowledge the support of the following companies or organisations:
Welcome to the Linux/VAX porting project. This is a port of the Linux Kernel to the Digital Equipment Corporation (DEC) (now owned by Compaq/Hewlett Packard) VAX and MicroVAX mini computer systems. VAX (Virtual Address eXtension) computers were designed and built from the mid-1970s through to retirement of the line in 1999/2000.
Here you will find all you need to get the Linux Kernel up and running on a VAX computer. We don't support many of the models yet, and it is very early days - we don't (at the time of writing) have dynamic libraries yet! But if you have one of the systems listed in the FAQ you can run a limited version of Linux on it. See the Documentation link for details on the installation process. However, its very rough at the moment, and you need to be very comfortable with the command line and root prompt to be successful.
If you don't like the idea of that, then we suggest that you visit our friends over at the NetBSD project at http://www.netbsd.org/ who make a free UNIX that runs on a wide variety of VAX hardware. NetBSD has a much easier installation, not to mention fewer bugs (at the moment...).
Still here?
You might like to join the Mailing list if you are serious about this...
The mailing list is somewhat imaginatively titled linux-vax. To subscribe, please visit http://www.pergamentum.com/mailman/listinfo/linux-vax. This is the Mailman interface for our list. Because the list used to life on a different machine, there are currently two archives, the old one at http://solar.physics.montana.edu/hypermail/linux-vax/ and the new one, which belongs to the mailing list mentioned above at http://www.pergamentum.com/pipermail/linux-vax/. They'll be merged soon, though.
Additionally, you could subscribe to the CVS checkin mailing list for Kernel (archive), toolchain (archive) and userland tools (archive).
This project would like to acknowledge the support of the following companies or organisations:
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