On Jun 22, 2014, at 1:26 AM, Mark J. Blair <nf6x at nf6x.net> wrote:
On Jun 21, 2014, at 19:31 , Steven M Jones <classiccmp at crash.com> wrote:
Not sure if this is exactly what you meant, but
SPICE (Simulation
Program with Integrated Circuit Emphasis) springs to mind.
Not exactly what I meant, but very much on-topic. I should see if I can get SPICE 2G.6
running on my VAX.
There?s an open source SPICE (?ngspice?).
I wonder what sort of software DEC used in their
hardware design and production back in the early to mid 1980s?
I remember PDP-15 systems being used for PCB CAD around 1978. And in late 1980 my boss,
lead DECnet/E designer, left that group a few months after hiring me as his junior
developer, to join a new IC CAD group being put together at DEC Hudson. I also remember
hearing of a thing called DECsim which sounded like a system (as opposed to IC) simulation
tool.
In the late 1980s, the Western Research Lab did some very interesting CAD work in a
project to build a single chip processor (MIPS-like, or Alpha-like?) in ECL technology.
That was unheard of ? no one was doing VLSI ECL. They developed their own tools that made
this possible, including being able to define a design in a process-independent fashion so
that they could switch from one fab to another ? changing layout constraint rules ?
easily. In the end, I don?t think the chip was built, but it produced some interesting
offshoots such as early designs for heat sinks and chip test fixtures that would work with
chips running at well over 100 watts.
One thing I remember about that CAD suite is that it let you define subsystems in a number
of ways ? geometry, transistor level, logic gate level, and C code. For example, you
could wrap a flip-flop in ?for (i = 0; i < 64; i++)? to define a 64-bit register. And
they could do behavioral models, power requirement analysis, and chip layout from a single
set of definitions.
I assume at some point there must have been a move to industry tools as opposed to
internally developed ones, but I don?t know when, or to what extent, that happened.
paul