Reminiscing About the Cubix ERS, My First Bladed Server System

In January, I made one of my semi annual pilgrimages to WeirdStuff, the amazing computer salvage store in Sunnyvale California. While prowling the back halls, between a smoke testing apparatus and a broken plotter, I spotted a Cubix ERS chassis. This brought back a flood of memories, since I purchased just such a device early in my career. This proto-blade server system was a decade ahead of its time, and I thought I might take a few minutes to describe it.

This is the Cubix ERS as I found it on the shelves at WeirdStuff

My cc:Mail Responsibility

The year was 1995, and I was a systems administrator responsible for e-mail messaging at a high-tech company in Massachusetts. This was my first full-time job, and was a result of my systems administration experience at college (WPI class of ’94) and as part of the GweepCo network cooperative/apartment. In short, I was as green as green could be but was learning the ropes of systems administration on a daily basis.

Some of my tasks included transitioning from SunOS to Solaris, configuring corporate SMTP with Sendmail, and maintaining and improving a Lotus cc:Mail environment. It was this last task that brought me face-to-face with the Cubix ERS/FT.

cc:Mail was a terrible system to manage, with frequent system interruptions due to database corruption and overloaded servers. The cc:Mail system relied on DOS servers to store messages and manage directory services. My company was fairly large, with locations in multiple countries around the world and the number of remote dial-up users.

The entire cc:Mail system was set up on a strange assortment of tower servers and scavenged desktop PCs. I wish I had a photo of the remote access stack, which featured half a dozen of Compaq 386 desktop PCs connected to US Robotics, Hayes, and Zoom modems. These computers were constantly locking up, so my first effort to improve availability was implementing a remote access power cycling solution: Rather than driving into work on a Sunday night, I could call in from my home and restart the computers.

Introducing the Cubix ERS

We also had a number of systems serving as gateways and mail servers. In all, the cc:Mail stack took up the better part of a wire rack and required almost constant care and feeding. We needed something better, with active management, a smaller footprint, and more reliable hardware. I spotted just such a device in a trade magazine: The Cubix ERS/FT.

I remember spending hours creating a document justifying the considerable expense of purchasing this amazing device, which cost more than the new car I had recently purchased. But I did justify it, and then spent months transitioning everything from the junky PC stack to this integrated rackmount solution. I left the company shortly thereafter, but always remembered the Cubix with fondness.

The Cubix Enhanced Resource Subsystem (ERS) was a high density PC compatible server solution from the mid-1990’s. I purchased mine in late 1995, loaded with a combination of 386 and 486 processor cards. The system allowed me to eliminate a stack of PC servers, but the ability to monitor and reset devices on command was far more useful.

The Cubix chassis featured dual power supplies and fans and could host up to 8 processor cards

The ERS chassis featured dual power supplies, a multiplexed floppy drive and shared keyboard/video/mouse (KVM) solution along with a supervisor card and software to manage everything. These chassis could be stacked and daisychained, allowing a single manager to control a multitude of servers. Although not exactly hot-swappable, the power supplies, fans, and just about everything else was easily accessible and removable. The entire chassis was mounted on slide out rails, a novelty at the time, at least to me. Access was through the top panel, with a hinged fan tray that can be lifted out of the way.

A Proto-Blade System, Not a True Blade Server

Although the Cubix system was certainly designed with the same goals as modern blade servers, it did not yet include some of the key technologies that would lead to the blade revolution. Processor boards and hard disk drives could be pulled and inserted while the rest of the system was running, but it was not truly hot-swap in the modern sense. The supervisor was ahead of its time, though I/O sharing was limited to KVM and each processor included its own I/O controller and ports.

The Cubix ERS used a segmented EISA backplane for processor card expansion. Each pair could be joined using a bridge board.

Inside the chassis was a 16 slot backplane divided, by default, into 8 segments. Each slot could hold a processor board or expansion card, and multiple segments could be joined together with a tiny bridging board if more expansion was required. Each processor board featured CPU, memory, controller circuitry, and basic I/O chips. Hard drives were connected via a ribbon cable that ran to the front of the chassis rather than being mounted on the processor boards themselves.

Hard drives were mounted at the front, under a hinged fan panel. Image courtesy of

I recall being able to power down a segment or group to replace a processor board or hard drive without affecting the rest of the running system. But this was a perilous maneuver, involving pulling out the entire chassis, lifting the lid, and unplugging a multitude of ribbon cables. I honestly never wanted to do that while the system was running.

The Cubix processor boards used ribbon cables for I/O and storage. Image courtesy of

The processors were specially made for communications applications, like my cc:Mail access set up. They monitored the serial ports and could be set to reboot when the modem disconnected or if the modem was no longer responsive. The supervisor also monitored other functions and could reset processors as needed. I believe it could also automate the power up sequence, allowing me to bring up the main cc:Mail database before powering on the access nodes.

The Cubix chassis featured integrated KVM and a multi-chassis supervisor module. Image courtesy of

Stephen’s Stance

In all, the Cubix ERS/FT was a great little system at the time. It really improved availability and performance of my cc:Mail system and cleaned up the data center at the same time. Although not quite as flexible as a modern blade server system, the Cubix ERS should go down in history as a worthy predecessor.

Cubix still exists today, unlike competitors like J&L Information Systems, ChatCom and CommVision. They focused on their bus expansion concept and now sell remote PCI Express chassis mainly used in the graphics world. It’s actually fairly cool stuff – how about a Thunderbolt model, guys?

Special thanks to WeirdStuff for existing, Alberto Rubinelli for permission to use his photos, and jpkiwigeek for being my kind of geek!

For more Cubix ERS joy, see this series of YouTube videos by user jpkiwigeek.

  • DeepStorage

    Cubix and the proto-blade had been around a while by the time you saw them my young friend.  Back in the early ’80s Industrial Micro Systems, Cubix’s original name, and several other vendors were selling Z-80 based systems using proto-blades on the S-100 bus.  

    One processor, the master, controlled access to shared I/O resources, primarily disk drives both floppy and hard, while up to 16 slave cards with processor, memory and serial ports ran applications.  Generally each slave acted as a single user’s PC and the users had dumb, or VT-100 not so dumb, terminals on their desks.  

    The whole thing was managed with either Digital Research’s CP-Net or a better CP/M compatible OS TurboDOS. The master acted as a disk server, like 3Com’s 3Share before they switched to LANmanager, so shared access to data required applications to be written to the system there being no file or record locking semantics.  

    As the PC took over Cubix and J&L (which became Chatcom) moved to x86 DOS architectures and sold most of their systems for remote access as each “blade” could run a modem for PC Anywhere type connections.

    Curious facts: 

    1 – My brother wrote, and my company at the time Pro-Comp Systems published, the definitive (ok only) book on TurboDOS, TurboDOS made Easy.

    2 – Novell Data Systems sold CP-Net based systems using RS-422 to link the master to the slaves before Ray Noorda came around and hired SuperSet to create NetWare.

    3 – I’m really old cause I remember all this.

  • sfoskett

    Best comment ever, Howard! You are old but great!

  • Etherealmind

    I also remember deploying Cubix servers for a “remote desktop” application using PC Anywhere in the early nineties. A 9600 baud phone was miraculous for mining companies at that time. 

  • Bigbird_ny

    I still have a “L/FTechnologies” (the interim name  between IMS and CUBIX) model 5000sx running in my lab.  its a hybrid with 5″ & 8″ floppies, two 85megs maxtors (still make that healthy “ta-da” sound on boot) QIC-02, and four 8-bit and two 16-bit slaves.  It supports a 16-bit master with TurboDOS  1.42+ and LF/net networking to an old PC that i keep running for just that reason.

    I can’t even count how many of these systems I installed over the years that they were built and all of them were retired old and grimey and in working condition.  I was Cubix’s service group in the NY-metro area and even stayed with them through their UNIX days and into the 1200 and 1400 blade series.

    Good times, they were.


  • Mr_New_Castle

    Bigbird_ny, are you still out there? I have some L/F Technologies and IMS hardware I’m trying to resurrect. Just wondering if you are willing to share some TurboDos resources. They made some really cool stuff, new_castle_j at yahoo

  • Mr_New_Castle

    I’ve been looking for a copy of TurboDos made Easy. Do you have one to share?