One of the more important innovations in System/390 is Enterprise Systems Connection Architecture or Escon, those long-awaited fibre optic channels, which enables installations to be dispersed over a radius of five and a half miles. The channels, which are optional, run at up to 10Mbytes-per-second using a new proprietary protocol. IBM characterises Esco as the first major advance in channel architecture since the System/360 in 1964, and it is accompanied by an Escon Director, which enables channel-to-control-unit or channel-to-channel connections to be dynamically switched among several paths. The Escon channels are supported on all ES/9000 processors. The other major new facility is multisystem coupling, or sysplex, where the clocks of up to eight machines can be synchronised to a master clock, which means that up to eight six processor machines can be run as a loosely-coupled complex – that’s a lot of MIPS. A companion console consolidation feature enables simplified operation of such a system complex: these features are supported only in MVS/ESA SP Version 4.2, due sometime next year. Within MVS/ESA SP 4 is a new APPC/MVS with SAA CPI Communications support to provide LU6.2 communications with other LU 6.2 devices such as OS/2 machines. The new version also provides for dynamic changes to the processor’s channel-attached input-output configuration definition so that the user can add, delete, or modify a hardware and software input-output configuration definition without shutting the machine down. The ES/9000 water-cooled models implement a new Integrated Cryptographic Feature that enables users to store, transmit, and manipulate data with the knowledge that the content of the data is secure from external access in any form other than encrypted. The new ES/9000 processors support the functions of ESA/390 architecture and System/370 architecture is supported only in a logical partition. New ES/3090-9000T transition models and some 3090 J-Models support ESA/370 architecture and parts of ESA/390 architecture.
