IBM 2361 Large Capacity Storage

The IBM 2361 Large Capacity Storage (LCS) is an optional component of the IBM System/360 models 50, 65 (when not being used as a multiprocessor), and 75 computers.

Up to 8 megabytes of slower (8 microsecond) Large Capacity Storage (LCS) was also available.

The IBM 2361 Large Capacity Storage (LCS) is an optional component of the IBM System/360 models 50, 65 (when not being used as a multiprocessor), and 75 computers.

The system can also attach IBM 2361 Large Capacity Storage (LCS) modules which provide up to 8,388,608 bytes of additional storage, however with a considerably slower memory cycle time of 8 microseconds compared to the 2 microseconds of processor storage.

The IBM 2361 Large Capacity Storage (LCS) is an optional component of the IBM System/360 models 50, 65 (when not being used as a multiprocessor), and 75 computers.

Storage is implemented using magnetic cores; the cycle time is 8 microseconds and the access time is 3.6 microseconds.

Storage is implemented using magnetic cores; the cycle time is 8 microseconds and the access time is 3.6 microseconds.

It provided additional main storage with a slower access time than the standard storage of the machine—for example its 8μsec compares to 750nsec for main storage on the Model 65.

The IBM 2361 was also provided to NASA for use on their IBM 7094 real-time system, where it supplied 524,000 36-bit words of additional memory.

The IBM 2361 was also provided to NASA for use on their IBM 7094 real-time system, where it supplied 524,000 36-bit words of additional memory.

If a system contained an even number of IBM 2361 components and at least one model 65 or model 75 processor, the IBM 2361s could be interleaved to improve sequential access time.

When doing sequential access, one IBM 2361 could complete its cycle while the other IBM 2361 was starting the next cycle.

OS/360 allows the user to request memory in either processor storage ("hierarchy 0") or the slower LCS ("hierarchy 1").

The OS/360 linkage editor also provides a control statement to assign specific control sections to a particular hierarchy, thus a program can be split into sections to run in processor storage and sections to run in LCS.

The OS/360 linkage editor also provides a control statement to assign specific control sections to a particular hierarchy, thus a program can be split into sections to run in processor storage and sections to run in LCS.

The system can also attach IBM 2361 Large Capacity Storage (LCS) modules which provide up to 8MB of additional storage, however with a considerably slower memory cycle time of 8 microseconds compared to the 750 nanoseconds of processor storage.

Note that while Carnegie Tech had a 360/67 with an IBM 2361 LCS, that option was not listed in the price book and may not have worked in a duplex configuration.