IBM System/370 Manual page 159

IBM programming systems support of these trends in data processing
has been growing and continues to be extended. The System/310 Model
165 offers the hardware, I/O devices, and performance capability
required
by
the expanding computing environment.
30:10 OS SUPPORT
It is expected that the majority of the users who upgrade to the
Model 165 will use OS as their operating system. The design of OS
and the facilities it currently provides make it a particularly suitable
base upon which to build additional support of the data processing
trends discussed. Some of the major OS features currently available
or announced are the following:
• Priority and job class scheduling for increased resource utilization
• Multiprogramming support of up to 15 user jobs and multitasking
facilities
• Automatic data transcription performed by the control program
(reader interpreters and output writers) concurrently with user
job execution
• Dynamic resource allocation by the control program
• Multiple console support (MCS) and device-independent display
operator console support (DIDOCS)
• Extensive teleprocessing and graphics support
• Remote job entry and conversational remote job entry
• Support of a wide range of interactive (time-sharing) environments
OS will be modified and extended in future releases so that it
supports Model 165 hardware. Appropriate alteration of the resident
portion of a control program (nucleus) generated for a Model 165 will
accommodate the fixed storage area of lower storage in the Model 165.
OS for the Model 165 includes currently announced OS facilities and
contains additional support to handle new Model 165 hardware features
and I/O devices. Emphasis has also been placed on extending error
recovery, recording, diagnostic, and repair procedures.
OS support of Model 165 features will be provided as follows
(Programming systems support of RAS features is discussed in Section
50).
New instructions. The Assembler F (Type I) and Assembler H (program
product) language translators will include mnemonics for the general
purpose and other new instructions for the Model 165 so that these
instructions can be used in user-written Assembler Language programs.
The currently available OS high-level language translators will not
generate the six new general purpose instructions.
Extended precision floating point. Assemblers F and H will include
support of the extended precision floating-point data format and
instructions. In addition, extended precision will be supported by
the FORTRAN H program product.
The implementation of extended precision support by FORTRAN
B
is
such that the language translator and the processing programs generated
to include extended precision operations can operate on a System/310
or System/360 with or without extended precision hardware. The language
translator contains extended precision instructions and generates them
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