Channel-to-channel adapter

IBM 704 mainframe at NACA in 1957

In IBM mainframe technology, a channel-to-channel adapter (CTCA)

- Channel-to-channel adapter

9 related topics


Channel I/O

High-performance input/output architecture that is implemented in various forms on a number of computer architectures, especially on mainframe computers.

Computer simulation, one of the main cross-computing methodologies.

Built-in channel-to-channel adapters were also offered, called CCAs in Amdahl-speak, but called CTCs or CTCAs in IBM-speak.

Virtual Machine Communication Facility

Feature of the VM/370 operating system introduced in Release 3 in 1976.

Teddy bear – VM's mascot since 1983.

It provides a simpler interface and greater performance than the prior use of virtual channel-to-channel adapters for the same purpose.


Component of z/OS that manages communications between applications in a sysplex.

IBM 704 mainframe at NACA in 1957

Dedicated channel-to-channel links (CTC links).

Remote job entry

Procedure for sending requests for non-interactive data processing tasks to mainframe computers from remote workstations, and by extension the process of receiving the output from such jobs at a remote workstation.

Example of data collection in the biological sciences: Adélie penguins are identified and weighed each time they cross the automated weighbridge on their way to or from the sea.

The initial versions of NJE for JES2, JES3 and VM RSCS used BSC multileaving, but IBM quickly added support for Channel-to-channel adapters.

IBM System/360 Model 50

Member of the IBM System/360 family of computers.

IBM System/360 Model 50 console and CPU with front panel
IBM System/360 Model 50 console and CPU with front panel
B&W closeup of 360/50 console

The I/O options include one channel-to-channel adapter (CTCA) and up to three selector channels.

IBM 303X

Discontinued line of mainframe computers, the first model of which, the IBM 3033 Processor, nicknamed "The Big One", was introduced March 25, 1977.

IBM 3033 frame, 3036 console (table) and 3277 terminals
IBM 3033 frame, 3036 console (table) and 3277 terminals
IBM 3033 and peripherals

An optional channel-to-channel adapter (CTCA) is available.

Attached Support Processor

Implementation of loosely coupled multiprocessing for IBM's OS/360 operating system.

EDVAC, one of the first stored-program computers

ASP was introduced in March 1967, and initially allowed connection of two System/360 computers via a channel-to-channel adapter (CTCA).

Global Resource Serialization

Component within the IBM z/OS operating system responsible for enabling fair access to serially reusable computing resources, such as datasets and tape drives or virtual resources, such as lists, queues, and control blocks.

GRS Ring - each of the systems (LPARs) are connected with channel-to-channel adapters (CTCAs) in a ring configuration. The GRS software sends messages around the ring to ensure the integrity of the complex and to arbitrate correct succession of ownership.

Job Entry Subsystem 2/3

Component of IBM's MVS mainframe operating systems that is responsible for managing batch workloads.

The computers were connected through selector channels on each host attached to channel-to-channel adapters in an early form of short distance, point-to-point computer networking.