Model Groups 1 & 2 announced Sep 15, 1983 and withdrawn Feb 11, 1986.
Model Group 3 announced Oct 25, 1984 and withdrawn Feb 11, 1986.
Model Groups 11, 12, 13 & 14 announced Feb 11, 1986.
Model Groups 21, 22, 23 & 24 announced May 19, 1987 and withdrawn Aug 19, 1992.
The following is the text of an undated IBM product brochure.
The IBM 4381 Processor is one of the most powerful and versatile intermediate system processors ever produced by IBM. Its system capabilities enable the 4381 to address an expanded range of user requirements in addition to providing growth for users of smaller, intermediate system processors.
|Processor Storage (MB)||4,8,16||4,8,16||8,16|
|High-Speed Buffer (KB)||24,32*||24,32|
|With 2K pages||4||16||-|
|With 4K pages||8||32||32|
|No. of 3MB channels||4||4||8|
* Processor storage sizes of 24MB and 32MB run in 4K page mode only.
4381 Areas of use
The performance range of the 4381 Processor and its features enable the 4381 to satisfy a variety of computing needs.
4381 Central site options
Twelve models of the 4381 Processor are available, offering three computing power options and various sizes of processor storage.
Processor storage upgrades can be made in the field.
Channel-to-channel adapter (#1850): One channel-to-channel feature is optionally available to interconnect two channels (4381 Processor, 4300 Processor, S/360, S/370, 30XX). One of processors requires this feature and three control unit positions on each of the connected channels. Maximum: one. Field Installation: yes. Prerequisite: one #4631 must be specified on the primary 3278 Display Console Model 2A or 3279 Color Display Console Model 2C. The 3205 does not require this feature.
Block multiplexer channels, additional (#1870) (Model Groups 1 and 2 only): An optional group of six block multiplexer channels. Enables simultaneous operation of high-speed devices a data rate of 2.0MB per second for two channels and 1.0MB per second for four channels. Maximum: one. Field Installation: yes.
Block multiplexer channels, additional (#1871) (Model Group 3 only): Two optional groups of three block multiplexer channels (six total channels). Permits simultaneous operation of high-speed devices at a data rate of 2.0MB per second for two channels and 1.0MB per second for one channel for each group. Maximum: one Field Installation: yes.
Each 4381 Processor requires one IBM 3278 Display Console Model 2A, 3279 Color Display Console Model 2C or 3205 Display Console which is equipped with an operator console keyboard and an operator control panel. A second 3278, 3279 or 3205 display console, although not required, will enhance system operations for most customers. For the Model Group 3, it is recommended that the second console be channel attached to the second processor. 3205s cannot be mixed with 3278s or 3279s.