4361 Processor

Model Group 5

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:

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:

• 16K bytes of high-speed buffer storage
• A separate ten megabyte per second channel processor
• Up to six channels
• A hardware accelerator for floating point multiply instructions
• A High Accuracy Arithmetic Facility
• A separate service processor that features a problem finder facility
• An Integrated Work Station Adapter to attach up to 32 terminals and intelligent workstations
• A Serial OEM Interface for attachment of OEM Subsystems and Devices
• Auto Start for automatic system start-up

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.

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

• Processor main storage -- starts from a minimum of 2,097,152 bytes. This storage is expandable up to a maximum of 12,582,912 bytes.
• High-speed buffer storage of 16K bytes -- provides a performance improvement by pre-fetching instructions and data from main processor storage into a high-speed cache buffer.
• Extended Control Program Support (ECPS) -- offers VSE mode, VM/370 mode, and MVS/370 mode. These modes provide microcode assists that make the system control programs operate more efficiently.
• A byte multiplexer channel -- supports the attachment of low-speed I/O devices. The channel operates at a maximum speed of 36K bytes per second in single-byte mode and up to 500K bytes per second in burst mode.
• Two block multiplexer channels -- support the attachment of higher-speed I/O devices such as tapes, printers, and terminal control units. Each channel is capable of supporting a data rate of up to 1,250K bytes per second.
• Display/printer adapter capability -- allows the local direct attachment of up to sixteen keyboard/display units, printers, and other work station devices.
• Serial OEM Interface (SEOMI) -- provides a Serial OEM Interface for attaching OEM subsystems and I/O devices via the display printer adapter and/or work station adapter using OEM standards e.g. IEEE 796.
• Dual drive diskette reader/recorder -- one drive supports the system and diagnostic microcode storage. The other is available for customer data recorded on an IBM type 1 diskette.
• High Accuracy Arithmetic Facility -- consists of twenty additional instructions. These are used by IBM software to provide verified maximum accuracy for floating point results.
• Remote support facility -- allows IBM Customer Engineers to remotely monitor system hardware and software They can then do problem diagnosis on the 4361 Processor.
• A problem finder facility -- provides the customer with detailed information on machine failures without IBM Customer Engineer involvement.
• Remote Operator Console Facility (ROCF) -- provides the capability to initially load and operate the 4361 from a remote location.

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:

• DASD/tape: up to four adapters are available on the 4361 Model Group 5 for the direct attachment of DASD and tape devices. Up to four strings of 3310, 3370 or 3340/3344 Direct Access Storage Devices may be attached on each of these adapters. Up to six 8809 Magnetic Tape Units may also be attached to each adapter. Attachment of DASD and 8809 units on any one adapter is mutually exclusive.
• Communications: the 4361 Communications Adapter can attach up to eight communications lines. SDLC, BSC and Start/Stop Line protocols are supported. One of the lines can operate at a maximum of 56,000 bits per second (bps). Each of the other lines can operate at a maximum speed of 9,600 bps. Maximum total data rate through the 4361 Communications Adapter is 64K bps. From one to eight lines may be configured from the optional communications adapter base. Other options such as modem type and line interface methods can also be selected.
• Loop adapters: the 4361 allows several terminal devices to be attached to the processor by a loop cable. These devices include 3640 Plant Data Control terminals plus a variety of display terminals, printers and terminal control units. (RPQ feature).
• Work Station Adapter (WSA): extends the local attachment of up to 40 advanced displays, printers and intelligent workstations (when the WSA is installed the number of ports on the Display/Printer Adapter (DPA) is reduced from 16 to 8 The number of ports available with the WSA is 32, using one 3299-1 Terminal multiplexer for each group of 8 ports. This provides a total of 40 parts on the DPA and WSA combined.) Support of 3270 extended data stream, 7 colors and programmed symbols, bigger screen size and APL keyboard are included.
• Auto Start: Auto Start loads the microcode, sets the TOD clocks and does initial program load at a predetermined time or after a power outage. An additional capability exists to start-up the system remotely by telephone using the Remote Operator Control Facility (ROCF).

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.

• The 4361 Model Group 5 can use the newest IBM I/O devices, as well as most established products that attach to the System/370 architecture processors. DASD support includes high-performance, large capacity devices such as the 3375 and 3380 that attach through the 3880 Storage Controller Magnetic tapes such as the 8809, 3410, 3420, and 3430 families attach to the 4361 Processor.
• Terminal devices that attach to the System/370 are also supported by the 4361. These include the 3270 family of terminals plus intelligent work stations such as the IBM Displaywriter and IBM Personal Computer.
• Industry terminals, such as the 3650 and 3660 families of store terminals, 3600 and 4700 Finance Industry terminals, 3630 and 3640 Plant Communications systems may all be attached to the 4361. ASCII terminals may be attached to the 4361 via direct communications lines or through the 4994 Communications Controller. The 4994 allows up to 48 ASCII terminals to be emulated to the 4361 as 3270 terminals.
• Printing capability is provided by a range of printers that include the 3800, 4245, and 4250.
• Other types of devices such as graphics units, image processing systems, plotters, sensors, laboratory instruments and microcomputers may be attached to the 4361 through the Device Attachment Control Unit which offers the choice of two industry standard electrical interfaces.
• Virtually all devices that attach to System/370 processors can also attach to the 4361 Model Group 5.

• SSX/VSE, VSE, OS/VS1, VM/System Product, and MVS/370 provide operating system support for the 4361 Model Group 5. The latest operating system releases capitalize on the maximum performance capacity and enhanced recovery of the 4361.
• ECPS features standard in the 4361 Model Group 5 provide microcode instruction assists for VSE, VM, and MVS modes.

• SSX/VSE is a pregenerated operating system that typically requires less than two hours installation time. SSX/VSE is the recommended operating system for 4300 batch/transaction processing installations where the system will be installed in a remote location or where customers are new to the 4300.
• System Installation Productivity Option/Extended (System IPO/E) offerings help provide easier installation and maintenance of VSE, VM/370 and OS/VS1.
• VSE/System Package further reduces system installation time for the VSE customer through a pregenerated offering. Easy to install and use, combined with the new capabilities, VSE will improve productivity of existing users as well as for new 4300 users.
• VM-based packages for business professional support and engineering/scientific support are available for the 4361. These special packages combine multiple IBM program offerings required in a specific environment into a single, integrated system, thus reducing overall installation time.
• MVS installation services are available from IBM. They provide initial MVS system generation services as well as VSE to MVS migration aids. This procedure greatly reduces the time required for IBM customers to begin and complete MVS migrations.