1

Danny Cohen Festschrift - 2 March 2013 - Chuck Seitz

Adventures with Danny

2

Danny Cohen Festschrift - 2 March 2013 - Chuck Seitz

Shared Experiences (Epochs)• Computer Graphics on Steroids

– Harvard 3D Display, Evans & Sutherland

• The VLSI Revolution– Caltech, USC/ISI, ARPA, …– MOSIS: The ARPA Silicon Broker– ATOMIC Network @ ISI ; Mosaic multicomputer @ Caltech

• SDI (Star Wars) Adventures– Eastport Study Group, chaired by Danny

• The early years of Myricom– Chuck & Danny were the senior founders

3

Danny Cohen Festschrift - 2 March 2013 - Chuck Seitz

MOSIS (MOS Implementation Service)

A wafer with 18 different die types A die with 4 different projects

4

Danny Cohen Festschrift - 2 March 2013 - Chuck Seitz

MOSIS in its early days

Putting many projects on one die started with Carver Mead at Caltech, who got student projects fabricated this way as a favor. Lynn Conway extended this idea with MultiProject Chip 1979 (MPC79) done by Xerox PARC for multiple universities.

ARPA asked ISI to take over this service for the ARPA VLSI program because ISI had the necessary people, computer resources, and infrastructure.

Technical challenges: faster turn, new technologies, …

Why did Danny agree to lead the MOSIS project initially?

MOSIS Express service between Southern California and Silicon Valley

5

Danny Cohen Festschrift - 2 March 2013 - Chuck Seitz

Strategic Defense Initiative

Eastport Study Group -- Our main conclusion:

Software technology is developing against inflexible limits in the complexity and reliability that can be achieved. The tradeoffs necessary to make the software task tractable are in the system architecture. As indicated in the Fletcher Report, the “applique approach” of designing the system first and then writing the software to control it is the wrong approach for SDI. System architecture and battle management must be developed together.

One promising class of system architectures for a strategic defense system are those that are less dependent on tight coordination than what is implied by the Fletcher Report. The advantages of this type of architecture include robustness, simplicity, and the ability to infer the performance of a full-scale deployment by evaluating the performance of small parts of the system.

Did our efforts make any difference?

6

Danny Cohen Festschrift - 2 March 2013 - Chuck Seitz

My children also wish to honor Danny

Danny giving my son Russell a flying lesson

7

Danny Cohen Festschrift - 2 March 2013 - Chuck Seitz

One thing Danny taught me about flying

1. Try to stay in the middle of the air.

2. Do not go near the edges of it.

3. The edges of the air can be recognized by the appearance of ground, buildings, sea, trees, and interplanetary space. It is much more difficult to fly in the edges.