discrete transistors

From: Eric Smith <eric_at_brouhaha.com>
Date: Mon Oct 19 00:58:56 1998

Allison J Parent
> Your unaware of many systems of the 60s that were large on performance
> and transistors. Your one transistor per cubic inch is far to low.
> I've worked with cordwood modules that were more in the 6 per cubic
> inch. Even flat boards were fairly dense.

No, one transistor per cubic inch is on the high side (as I describe
in a previous posting). Sure, you can make cards that have a dozen
discrete transistors per cubic inch (without even going to SOT-23
packages).

But you can't build a *system* with that overall density.

IBM didn't achieve densities better than one transistor per cubic
inch until they switched from SMS cards (discrete components on small
printed circuit board modules, similar to DEC R and B series modules)
used in the 7000-series computers to SLT (hybrid integrated circuits on
ceramic substrates, first used in System/360 in 1964).

References:

        _IBM's Early Computers_
        Charles J. Bashe, Lyle R. Hohnson, John H. Palmer, Emerson W. Pugh
        MIT Press, 1986 (out of print) ** This book is a must-have **

        _IBM's 360 and Early 370 Systems_
        Emerson W. Pugh, Lyle R. Johnson, John H. Palmer
        MIT Press, 1991

        _Memories That Shaped an Industry_
        Emerson W. Pugh
        MIT Press, 1984

        _Building IBM: Shaping an Industry and Its Technology_
        Emerson W. Pugh
        MIT Press, 1995

        _Planning a Computer System: Project Stretch_
        Werner Buchholz, editor
        McGraw-Hill, 1962 (out of print)

        _Computer Architecture: Concepts and Evolution_
        Gerrit A. Blaauw and Frederick P. Brooks Jr.
        Addison-Wesley, 1997
Received on Mon Oct 19 1998 - 00:58:56 BST