CDC SCOPE
| Industry | Computer software, Computer hardware |
|---|---|
| Founded | 1957 |
| Headquarters | Minneapolis , United States |
| Products | SCOPE operating system, CDC supercomputers |
SCOPE (Supervisory Control of Program Execution) refers to a collection of batch operating systems created by Control Data Corporation during the 1960s.
Variants
- SCOPE designed for the CDC 3000 series
- SCOPE tailored for the CDC 6000 series
- SCOPE and SCOPE-2 implemented on the CDC 7600/Cyber-76
SCOPE for the CDC 6000 series
Originating from the Chippewa Operating System, this OS was rebranded as NOS/BE in the early 1970s for use with CDC Cyber machines. As a file-centered system, SCOPE was optimized for managing mass storage and random access devices, fully exploiting the features of CDC 6000 hardware, including support for multiple operating modes. It oversees job scheduling, memory allocation, and segment loading, incorporating extensive input/output capabilities along with library management. The system maintains a chronological record of all jobs and errors and offers memory dumps and maps to aid in troubleshooting.
Description
SCOPE is a multiprogramming OS enabling simultaneous operation of up to eight jobs ("control points"), with one reserved for system-level tasks; subsequent iterations expanded this capacity to 15.
The OS runs on the 6x00's peripheral processors (PPs), each capable of exercising complete control over the central processor (CP). PP0 executes the Monitor Program (MTR), which supervises all system functions, while PP9 is dedicated to managing the system console. The remaining PPs handle input/output operations under MTR’s supervision.
A portion of central memory, known as the Central Memory Resident (CMR), holds critical system tables accessible by all PPs. Each PP is allocated a communication area within the CMR that includes input/output registers and message buffers.
During a cold boot, all PPs load their respective system code from magnetic tape; PP0 launches the monitor program, while other PPs wait for commands through their input registers.
Software
By version 3.3, SCOPE supported programming languages such as ALGOL, BASIC, FORTRAN, COBOL, and COMPASS (assembler), alongside APT, CSSL 3, JOVIAL, SIMSCRIPT, and SIMULA. Additional software offerings included IGS (Interactive Graphics System), PERT, and SORT/MERGE.
CDC machines were categorized as supercomputers and predominantly served large governmental bodies and research organizations. These users often had unique requirements and frequently developed customized software solutions internally.
Competition
SCOPE was created by a development team based in Sunnyvale, California, distinct from CDC’s hardware engineering group located in Arden Hills, Minnesota. The hardware division viewed SCOPE as unreliable and inefficient, humorously dubbing it Sunnyvale's Collection Of Programming Errors. In response, Arden Hills engineers developed an alternative operating system called MACE (Mansfield And Cahlander Executive), which evolved from an engineering test executive into a modular rewrite of the Chippewa Operating System (COS). Though never officially endorsed by CDC, MACE was distributed freely to customers—particularly those with advanced needs such as universities and research institutions.
When CDC introduced its successor OS, Kronos, it was based on MACE rather than SCOPE. Kronos itself was eventually superseded by the Network Operating System (NOS). Many smaller CDC clients continued to rely on SCOPE for batch processing tasks, prompting CDC to maintain it under the NOS/BE (Batch Environment) name to support marketing claims that all mainframe users operated NOS.
Current status
Enthusiasts within the computer emulation community have made significant efforts to recover and safeguard CDC software, which is currently operable on CDC CYBER and 6000 series emulator environments.