CP-67
| Company type | Software |
|---|---|
| Industry | Virtualization software |
| Headquarters | Cambridge , United States |
| Products | Hypervisor (Virtual Machine Monitor) |
| Parent | IBM |
CP-67 represents a hypervisor (Virtual Machine Monitor) engineered by IBM specifically for the System/360 Model 67 system.
It functions as the control program element within CP/CMS, a virtual machine operating system developed at IBM's Cambridge Scientific Center located in Cambridge, Massachusetts. CP-67 is essentially a redevelopment of the prior experimental system CP-40, which operated on a customized S/360-40. This innovation later progressed into CP-370, introduced as VM/370 in 1972, coinciding with the implementation of virtual memory in the System/370 line.
While CP and CMS are commonly associated, they operate independently: CP-67 can run without CMS on compatible hardware, and CMS can function as a standalone single-user system on an appropriately configured System/360 without CP-67.
Minimum hardware configuration
The essential hardware requirements for CP-67 consist of:
- 2067 CPU, either model 1 or 2
- 2365 Processor Storage model 1 — providing 262,144 bytes of magnetic core memory with an access time of 750 ns per eight bytes
- IBM 1052 printer/keyboard device
- IBM 1403 printer
- IBM 2540 card reader and punch unit
- Three units of IBM 2311 disk storage, each offering 7.5 MB (totaling 22.5 MB)
- IBM 2400 magnetic tape data storage device
- IBM 270x Transmission Control unit
Installation
Disk formatting for CP is performed using the standalone utility FORMAT, which is loaded from tape or punched cards, handling fixed-length records of 829 bytes. Another tool, DIRECT, divides disk space into permanent sections (for system and user files) and temporary areas (used for paging and spooling). Additionally, DIRECT establishes the user directory by defining virtual machines (users), assigning IDs, passwords, and setting resource permissions. Users generally interact with virtual devices such as spooled card readers, punches, and printers. Disk allocation occurs through one or more virtual disk units known as "minidisks", which mimic physical disks but represent partitions within actual device storage.