Back in March of 2025 a branch named "dual-state" was created in the DtCyber GitHub repository. Steady progress in implementing support for the CYBER 180 series of CDC supercomputers has been made on that branch since then. The work has finally reached the point where the code is mature enough to be merged back into the main DtCyber branch, and that merge occurred today.

The dual-state feature represents a very significant enhancement to DtCyber. Thus, DtCyber's major version number has been incremented. As of today, the latest version is DtCyber 6.0.30.

All models of CDC CYBER machines previously supported by DtCyber continue to be supported, and they continue to run all of the operating systems they've been running until now. That includes COS, KRONOS, HUSTLER, NOS 1, NOS 2, NOS/BE, etc. In addition, DtCyber now also supports a new machine model: CYBER 180 Model 860.

The CYBER 180 Model 860 was a dual-state machine. It implemented both the CYBER 170 instruction set and the CYBER 180 instruction set, and it could run NOS or NOS/BE concurrently with the NOS/VE operating system. The CYBER 180 series machines and NOS/VE were state-of-the-art in their time, but in retrospect, they came to market too late to be very successful, and they missed the paradigm shifts represented by minicomputers and personal computers.

The CYBER 180 and NOS/VE are historically significant in that CDC placed an enormous bet on them. CDC invested many millions of dollars and at least a decade of development in these technologies. Instead of designing technology to succeed the CYBER 170 that represented an incremental improvement, CDC designed the CYBER 180 as a radically more advanced machine. For example, the CYBER 180 was a byte-addressable, 64-bit machine with a 44-bit segmented address space and virtual memory. Each process could have as many as 4096 segments of memory, each up to 2 gigabytes. The highest end models of the 180 series also had vector instructions. The CYBER 180 had 16-bit PP's too.

NOS/VE was also radically different from its NOS and NOS/BE predecessors. It was strongly influenced by MULTICS and contemporary academic thinking about state-of-the art operating system design and user-friendliness. To facilitate migration from NOS or NOS/BE to NOS/VE, most of the CYBER 180 models supported the CYBER 170 instruction set in addition to the CYBER 180 instruction set, and NOS or NOS/BE could run concurrently on the same hardware as NOS/VE. NOS/VE had a kind of "hypervisor" called the Environment Interface (EI) that enabled the machine to run the two very different operating systems concurrently.

The EI also enabled communication between NOS (or NOS/BE) and NOS/VE. Prior to general availability of the CDCNet product, the EI enabled NOS (or NOS/BE) to serve as a frontend to NOS/VE. For example, a NOS application named VEIAF was provided to enable users to log into NOS/VE interactively via NOS. NOS could also submit batch jobs to NOS/VE and receive output from NOS/VE to be printed on its printers.

A preconfigured dual-state system can be installed using the install.js script in the NOS2.8.7 directory of the updated GitHub repo. For example, to create an up-to-date repo, build DtCyber 6.0.30, and install a dual-state NOS and NOS/VE system, execute the following commands on macOS or Linux:

git clone https://github.com/kej715/DtCyber.git

(or git pull to update an existing repo)

cd DtCyber

make -f Makefile.macos all

(or for Raspberry Pi 4 or 5: make -f Makefile.linux64-armv4-a all)

(or for other 64-bit Linux systems: make -f Makefile.linux64 all)

cd NOS2.8.7

sudo node install rtr dual-state-860

On Windows, use VisualStudio to build the DtCyber solution, and then execute the following commands to install the ready-to-run dual-state system:

cd NOS2.8.7

node install rtr dual-state-860

Note that node.js must be installed on macOS/Linux/Windows to run the install.js script that installs the ready-to-run dual-state system.

The install.js script installs a CYBER 180 Model 860 running NOS 2.8.7 and NOS/VE 1.8.3AA. Both NOS and NOS/VE will have logins INSTALL and GUEST (with passwords same as usernames). As soon as the NOS/VE console window (the window titled TPM 0) displays the prompt

sou/

NOS/VE has finished its deadstart process, and you can log into it. This can be done by logging into NOS as usual and then entering the command:

HELLO,VEIAF

To shutdown NOS/VE gracefully, enter the following command in the NOS/VE console window:

terminate_system

cheers,
Kevin