The following is the text of an undated IBM product brochure probably published in 1984.

The IBM 4361 Processor combines leading-edge technology, efficient packaging and design, general System/370 compatibility and outstanding price/performance in its three model groups: 3, 4 and 5.

The 4361 Processor Model Group 5 offers a powerful computing system that can do a variety of tasks: commercial online and batch work, interactive problem solving, and engineering/ scientific jobs. In addition, the 4361 Model Group 5 offers an attractive growth option from other IBM systems.

Up to 12 megabytes of monolithic processor storage are available in the following models:

Model Processor storage (Bytes)
K5 2,097,152
L5 4,194,304
LK5 6,291,456
M5 8,388,608
ML5 12,582,912

Any installed 4331 Model Groups 1, 11, or 2, or 4361 Model Groups 3 and 4 may be field upgraded to a 4361 Model Group 5, which gives significant growth option to users of these systems without processor replacement. Under normal circumstances, field upgrades from 4331 models require about 18 hours of system time.

Field upgrades from 4361 Model Groups 3 and 4 require about 6 hours. (Upgrade time and throughput performance is highly dependent on factors within the control of the user. References in this brochure should be used for example purposes only, and are not meant to be accurate representations for any particular customer's application.)

The throughput of a 4361 Model Group 5 is approximately equal to a 4341 Model Group 2 for commercial and engineering/scientific workloads. Commercial throughput for the 4361 Model Group 5 is about three times that of a 4331 Model Group 2 and about 1.4 times greater than the 4361 Model Group 4.

The 4361 is a virtual storage system with System/370 compatibility. It features Very Large Scale Integration (VLSI) technology in the processing units. It is designed for minimum physical space requirements. It offers integrated attachment options, plus low power and cooling requirements. The 4361 is an ideal system for installation in a department or remote location where data center facilities may not be practical. The 4361 Model Group 5 also offers large system capabilities through a wide range of standard and optional features:

Extended Control Program Support (ECPS) facilities help improve processor performance for VSE, VM/370, and MVS/370. ECPS provides additional microcode in the 4361 for the execution of commonly used control program functions, thus aiding in overall system performance.

Standard features

The 4361 Model Group 5 has a full complement of processor functions to control the operating environment:

Optional features

The 4361 Processor is designed to serve both as a less complex, department level system and as a powerful mainframe computer. Thus, a choice of two device attachment methods is provided:

Integrated I/O adapters provide a less expensive means of attaching devices, primarily because no external device control unit is required. In addition to the standard display/printer adapter, the following optional integrated adapters are available on the 4361 Model Group 5:

The 4361 also offers the option of attaching direct access storage through an external control unit attached to a high-speed channel if that better fits the system requirement.

Up to three high-speed block multiplexer channels are available on the 4361 Model Group 5. Two of the channels can support a data rate of up to 3 million bytes per second. The high-speed channels can attach direct access storage devices such as the 23XX, 3330/3333, 3340/3344, 3350, 3370, 3375 and 3380.

Wide range of I/O

Programming support

Installation aids

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