IAS

Institute of Advanced Study, Princeton

John von Neumann with the IAS Machine, which was inaugurated in 1952

In many ways the first "modern" computer in terms of the way memory is seen, and formed the basis for many subsequent designs, the IAS design was possibly the biggest single step in early computer design.

key points:

• stored program (in same memory as data)
• modern idea of an arithmetic unit that executes instructions
• modern idea of memory addresses
• indexed addressing
• instructions assumed to execute in sequence (i.e., idea of a branch instruction)
• total memory size 4000 words of 40 bits
• key performance targets: multiply in 100 microsec, memory access in 50 microsec
• hierarchy of small fast and big slow memories
• introduced the concept of microscopic memory elements (storage tube)

It's interesting that even though Von Neumann either originated or clarified many of the key concepts, British researchers were able to build real systems embodying these principles years earlier.

A Burks, HH Goldstine and J von Neumann. Preliminary Discussion of an Electronic Computing Instrument, part 1 vol. 1, Institute for Advanced Study, Princeton, June 1946 (2nd edition September 1947). Reprinted in B Randell (ed.). The Origins of Digital Computers, Springer, Berlin, 1975.

Memories are Made of This 17:30 Thurs 12 September 1996 SHB5, Senate House, University of the Witwatersrand, Johannesburg, South Africa