Model Groups 4 & 5 announced 09/15/83, withdrawn 02/17/87. ModelGroup 3 announced 09/12/84The following is the text of an IBM Information Systems Group press fact sheet distributed on September 10, 1984.
Commercial performance equivalent to the 4331 model 2.
Factory installed option increases engineering/scientific performance up to 1.4 times the model 2 for short precision and 2.2 times for long precision.
High-Accuracy Arithmetic Facility:
Allows computational procedures with algorithmic verification of results.
New floating-point instructions are implemented for computation of basic arithmetic operations and the scalar product with maximum accuracy.
Provides direct rounding for the short and long floating-point hexadecimal formats.
Microcode-assisted support for improved performance of frequently used mathematical functions.
2 or 4MB of processor storage.
Integrated I/O attachments and standard I/O interface channels for maximum system configuration flexibility.
Integrated DASD Adapter support.
Up to three data channels.
Field upgradable to models 4 and 5.
Extensive programming support, including VM/SP, SSX/VSE, VSE/SP and OS/VS1.
New 4361 standard features
Serial OEM Interface -- for attaching a variety of non-IBM subsystems, workstations and devices. Board-level microcomputer devices attach to the interface with adapters that provide conversions and control functions.
Programmable Power-Off -- enables the user to turn off the processor under program control.
Problem Determination -- three software tools for user-initiated problem determination: Problem Finder Facility, System Event Trace and System Status Display.
New 4361 optional features
Workstation Adapter -- supports the following features/functions beyond the Display/Printer Adapter:
3270 extended datastream for extended highlighting.
Seven colors and programmed symbols.
Screen sizes up to 3,564 characters.
Combination of both adapters provides 40 ports for attachment of workstations including IBM Displaywriters and Personal Computers.
Auto-Start -- automatically turns on the processor by telephone via the Remote Operator Control Facility or at a predetermined time and day of the week. The processor powers on and proceeds with initial microcode load, sets the clock and loads the system.
Floating point multiply accelerator
Standard feature for models 4 and 5.
Factory installed option for model 3.
Improves multiplication execution times by a factor of 3 to 8 over microcode implementations.