Contents
View on Plan
Click to see bigger picture
System/360 Model 30
Gift of Frost and Sullivan, X1059.91
Click to see bigger picture
System/360 computer system, 1965
1965
Credit: IBM Archives

System/360 Model 30
1965
IBM Corporation, United States

In April 1964, IBM announced the System/360. A new line of unified, compatible computers, the largest of which was 40 times faster than the smallest. The line was highly successful and the 360 architecture dominated the mainframe computer industry for over three decades.

The entry-level Model 30 shown here was first shipped in June 1965.

Memory Type:CoreSpeed:1,300 Add/s
Memory Size:64KCost:$133,000 +
Memory Width:(8-bit)Click to see technical notes

OS/360
1965
IBM Corporation, United States
Click to see bigger picture

System/360 Principles of Operation Manual

Click to see bigger picture

The Mythical Man Month, Fred Brooks

Click to see bigger picture

Fred Brooks with several System/360 machines, c. 1965
Credit: Fred Brooks

System/360 software included a new programming language (PL/1), revised versions of older languages (such as FORTRAN, COBOL, and RPG), and a very complex new operating system that would run on all machines in the 360 family. OS/360’s complexity was highlighted in project manager Fred Brooks’ 1975 classic book The Mythical Man Month as an example of the “Second System Effect.” This phenomenon, he explained, leads designers of successful systems to overdesign and unnecessarily embellish their second system.

Click to see bigger picture
System/360 Model 91 Console
Gift of Stanford Linear Accelerator Center
Click to see bigger picture
System/360 Model 91 at Goddard Space Flight Center
c. 1968
Credit: IBM Archives

System/360 Model 91 Console
1968
IBM Corporation, United States

The Model 91, was one of the fastest machines in the IBM System/360 family, was primarily used for scientific applications. The first 360/91 began operating in January 1968 at the NASA Goddard Space Flight Center.

The computer used IBM Solid Logic Technology (SLT). This advancement involved encapsulating five or six transistors into a small module and represented a bridge between discrete transistors and the integrated circuit.

Memory Type:CoreSpeed:16,700,000 Add/s
Memory Size:64MCost:$5,500,000 +
Memory Width:(64-bit)Click to see technical notes