Long gone, DEC is still powering the world of computing

 

Even though very few of the early players in technology still exist, we use their creations to this day. Bell Labs created the transistor, and Fairchild Semiconductor created the integrated circuit, but neither company is still around. So is the case with Digital Equipment Corporation (DEC). It no longer exists, but unless you're using a handheld device to read this article, you're using a descendant of DEC technology.

 

DEC was founded in 1957 by Ken Olsen, Harlan Anderson, and H. Edward Roberts to build small digital modules, but the team soon discovered that they could use those modules to build minicomputers—computers that were smaller and less powerful (but cheaper) than mainframes, which were the business standard at the time.

 

In 1977, DEC introduced the VAX, a new line of minicomputers that featured a 32-bit instruction set architecture and virtual memory. Its operating system, VMS, was a multi-user, multitasking OS that provided features we now take for granted, including virtual memory, file sharing, and networking. It amassed a wide variety of third-party software packages that made it the most popular system in its class.

 

In the late 1980s and early '90s, Andy Green ran a bulletin board system (BBS) and later an Internet service provider called Intelecom Data Systems (IDS) on a VAX 11/730 (later a VAXstation 4000) server in the basement of his parents’ house in Rhode Island. IDS had seven lines—unheard of at the time—and users could talk in a real-time chat room. All of this was written by Green in VAX BASIC. Today, Green is the owner and CEO of Acme Atronomatic, developer of the MyRadar mobile app.

 

Green was exposed to the VAX through work and had picked up an old VAX 11/730 and started tinkering. He had previously run a BBS on a TRS-80, but the VAX, with its multitenancy, allowed for multiple concurrent users.

 

“Prior to [IDS], the PC or TRS-80 were only engineered originally to be single-user, and they weren't set up to be multi-user,” Green told Ars. “The fact that VAX and VMS in general were designed for [multiple users] from the scratch is what facilitated the multi-user aspect.”

 

The VAX served DEC well throughout the '80s and into the '90s, but as the latter decade went on, DEC began to face stiff competition from UNIX vendors, particularly Sun Microsystems. DEC struggled to change with the times, and the company ultimately failed. In 1998, DEC was acquired by Compaq, and in 2001, Compaq was acquired by Hewlett-Packard. The DEC line, including the VAX/VMS system, was discontinued and faded from the market.

 

And yet it lives on today. Here’s how.

VMS=WNT

VMS was popular because DEC supported it so thoroughly. It had a user-friendly interface and powerful command-line tools, and it was one of the first operating systems to support networking protocols, including TCP/IP, DECnet, and SNA. It had a powerful file system that supported hierarchical directories and file permissions, and it was highly customizable.

 

In 1988, a senior VMS engineer named David Cutler joined Microsoft to lead the development of the Windows NT operating system. Windows NT was a major departure from previous Microsoft operating systems, as it was a 32-bit, multi-user, multitasking OS. Windows client, still finding its way to usability, was a 16-bit layer that ran over MS-DOS. It wasn’t really an operating system; it was more like a program launcher.

 

Windows NT launched in 1993 with version 3.1, matching the desktop version of Windows, which had also just been released. But while Windows 3.1 finally got it right, NT 3.1 was a bit too heavy for the PCs of the day, and it was recast as a server operating system.

 

Both operating systems continued on separate but iterative tracks, with Windows for desktop becoming Windows 95/97 and NT becoming version 3.5, version 4.0, and eventually Windows 2000. It wasn’t until the release of Windows XP in 2001 that the consumer and business products were merged into one line based on NT.

 

XP begat Windows Vista (a bad memory best left for the past), the vastly improved Windows 7, and the disastrous Windows 8, then Windows 10 and finally Windows 11.

 

Cutler and his team didn’t copy VMS, per se, but a lot of the structural elements and functions, such as the network file system, networking protocols, security, and memory management, were duplicated in NT.

 

Green saw the resemblance right away. “There definitely were some similarities between NT and VMS,” he said. “The permissions systems, file protection mechanisms, privileges and roles—those were some security concepts integrated into VMS that were unique at the time but incredibly useful and configurable. NT implemented very similar paradigms, and it definitely makes sense, now, knowing the heritage.”

 

“There is an undeniable shared heritage between the two,” said Wes Miller, analyst with Directions on Microsoft. He noted that multiple features in NT look “strikingly similar” to VMS. “It's just fascinating when you go back and look at it the way the process scheduler works, the way task prioritization works. There's a lot in common between the two.”

 

“I would say [NT] bears a lot of similarities [to VMS],” said Nathan Brookwood, a research fellow with Insight 64 who worked for DEC before becoming an analyst. “The command structures and user interfaces were very similar.”

 

And in fact, the innovation went both ways, Miller noted. The Registry, a hierarchical database of a system’s hardware and software configuration, was first designed for NT, and DEC then introduced its own Registry in VMS 7.3.

 

How much of the original Windows NT 3.1 code written by Cutler and his team more than 30 years ago remains in Windows 11 is unknown. Recent versions of Windows for both client and server have shed 16 bit application compatibility, and this was definitely a function found in Windows NT 3.1 to version Windows 2000. Back in the early to mid-'90s, most applications were 16-bit, and 32-bit only began to creep into the market later in the decade.

 

Even the 32-bit support in current versions is only through a compatibility mode called “Windows on Windows” and not native. As Windows inevitably marches to 64-bit-only, “you've got to jettison some of the old stuff,” said Miller. Which means more of the old code disappears from the operating system.

 

“[16-bit] sort of died out when AMD64 came along, and the team that was working on it decided not to port 16-bit software support. When they went full 64-bit, you had a 32-bit subsystem but no 16-bit support. So there's never been a 64-bit version of Windows that supports 16-bit applications,” said Miller.

Alpha and Omega

The second piece of the puzzle is the CPU. Unless you use a Mac, your computer's CPU has its roots in a DEC processor that failed in the market.

 

In the late 1980s early '90s, DEC was looking to change with the times and evolve its VAX line. In 1992, it introduced the Alpha AXP, later shortened to just Alpha, a RISC-based processor designed to compete with the other RISC chips on the market such as Sun Microsystems SPARC and Hewlett-Packard’s PA-RISC.

 

“DEC was getting its lunch eaten by the RISC guys, particularly Sun, but also, to a certain extent, Silicon Graphics with their MIPS products, both of which were based on this newfangled RISC environment,” said John Culver, a CPU historian and operator of The CPU Shack.

 

“They knew that they had to improve or get competitive with performance. So they looked at all the alternatives, which were basically to try to make the VAX faster or to come up with an architecture that they thought would be very competitive in the market. And that turned out to be Alpha.”

 

Alpha one-upped them all by being 64 bits at a time when everything else was 32-bit. Bits don’t change the processing power; they just change the amount of addressable memory, and back in 1992, no one was worried about the 4GB theoretical memory limits of 32-bit computers. In that regard, the Alpha was way ahead of its time.

 

“Everyone was like, 'Why would I need more than four gigabytes of RAM?' It was the right thing to do, but it was too early. You see that in a lot of things where they're ahead of their time, and [people] don't know what to do with it,” said Culver.

 

Alpha had more going for it than just 64 bits. It was faster than an Intel processor and had a more efficient instruction clock. The one thing it didn’t have going for it was software. DEC provided multiple operating systems: OpenVMS, Tru64 UNIX (previously named DEC OSF/1 AXP and Digital UNIX), and, for a very short period, Windows NT.

 

But the UNIX market in the 1990s was severely fragmented. There was Sun Microsystems with two operating systems, the BSD-based SunOS and Unix System V-based Solaris. HP had HP-UX, Silicon Graphics had IRIX, and IBM had AIX. Software developers hate market fragmentation, so they eventually coalesced around the winners and leaders, and DEC wasn’t one of them. It was a company in trouble, with slowing sales of limited resources. And because it did its own chip manufacturing, it struggled to make enough processors.

 

“They didn't have the money to invest in ramping up, accelerating the architecture, getting clock speeds up, shrinking processes. And this is in the '90s, when Intel is manufacturing king,” said Culver.

 

So DEC did what every company in trouble does: It slashed spending and eliminated product lines. That included the Alpha.

 

Around this time, Sun also got into a bit of trouble and began reducing headcount in its SPARC division. It just so happened that those developers were in the Boston, Massachusetts, area, and DEC was in nearby New Hampshire. Sensing an opportunity, AMD opened up an office outside Boston and populated it with ex-chip engineers from DEC and Sun. That included Dirk Meyer, a co-architect of the Alpha.

 

The company would develop what would become known as the K7 generation, better known as Athlon. It was home to many firsts: Athlon was the first CPU to hit 1 GHz, the first to use multiple cores on one die, the first to incorporate the memory controller in the CPU, and, with the next generation K8, the first to feature 64-bit x86 extensions.

 

K7/K8 borrowed more than a few ideas from the failed Alpha processor, most notably the CPU bus and the 64 bit extensions and similar cache structures. This was at a time when Intel’s 64 bit strategy relied on the ill-fated Itanium. Like the Alpha, it suffered from a severe lack of software. It offered x86 simulation, but packaged x86 software ran unacceptably slow.

 

Intel began to realize that Itanium was not the way forward. Culver said the company had two options: develop its own x86-64 extensions or license them from AMD, which was offering them to anyone who wanted them. Realizing that it would take years of development and potentially lost ground to AMD, Intel CEO Craig Barrett made the hard decision to license the extensions from AMD, thus forever joining Intel and AMD at the hip. It was a severely bitter pill to swallow.

 

“I remember when he announced it at the Intel Developer Forum in 2004. He looked like he would rather have been having a tooth pulled without any anesthesia,” said Brookwood.

 

“Prior to that announcement, there was considerable doubt as to whether Intel would offer its own, incompatible version of 64-bit extensions and split the industry,” said Brookwood. “It was a great relief when they didn't. It later emerged that it was pressure from Microsoft, who told Intel that they were going with the AMD64 extensions, and no other. I suspect that Dave Cutler drove that decision on Microsoft’s part.”

 

Thanks to its lead over Intel, AMD benefited handsomely and was in the server business for the first time in a big way. It then stumbled in 2006 with the Barcelona generation of processors, which were very late and buggy. AMD lost all of its momentum, and Intel, under the new leadership of Paul Otellini, regained its momentum. AMD would go through a string of CEOs, including Meyer, before the hiring of Lisa Su in 2014.

 

Su has transformed AMD from a $4-billion-per-year company into a $25-billion-per-year company—and a major thorn in Intel’s side (Nvidia, not so much), but she had some help, again, from DEC. In 2017, AMD introduced the Zen microarchitecture, a completely redesigned processor with vastly better performance than the previous generation and very competitive with Intel’s best. A key member of the development team was Jim Keller, who is legendary for two things: outstanding CPU designs and not staying put. In his career, he has worked for DEC, Intel, Apple, AMD (twice), Tesla, and a number of smaller companies.

 

He originally came to AMD from DEC and was part of the K7 team. He left to join SiBite, which was later acquired, then joined PA Semi, which Apple acquired. Keller worked on the A4 and A5 chips before rejoining AMD to work on Zen.

 

DEC also experimented with the Arm processor with a team based out of Hudson, Massachusetts, and developed the StrongARM line of processors. Intel took over this group in 1997, which was rebranded XScale. In 2006, Intel sold the line to Marvell, feeling there was no future in mobile markets. It was proven very wrong on that one.

The Mac Connection

And as it turns out, there's a connection between Apple and DEC as well. Dan Dobberpuhl was one of the original Alpha designers before he left DEC to start a chip design firm called P.A. Semi, which Apple bought in 1998 for its talent to work on their Arm processors. They developed the chips used in the iPad and iPhone and eventually the M1 and M2 processors used in the Mac line. Other members of P.A. Semi would go to AMD to work on the 64-bit Opteron server line.

 

So if you are reading this on a computer or iPad, you are doing so thanks to DEC.

 

Digital Equipment Corporation has long since ceased to exist. Its VAX hardware has been consigned to computer museums and replaced with commodity x86 servers that its engineers had a hand in creating. The major players are largely gone; many ex-DEC people are retired, including Cutler, who is in his 80s (Microsoft declined to offer him for an interview).

 

Meyer has disappeared. He has no LinkedIn profile and hasn’t been involved in any companies for over a decade. Even AMD couldn’t find him. Keller is one of the last remaining people involved with the Alpha and x86-64 still active in the industry.

 

But DEC's technology—and the companies it helped bring to life—are very much still an active part of our world.