70's computers

[Noel Chiappa]

    > From: Ben Bfranchuk

    > I just can't find a clean simple design yet. ...
    > The PDP 11 is nice machine, but I am looking  for simpler designs
    > where 16K words is a valid memory size for a OS and small single user 
    > software.

There was a recent discussion about code density (I forget whether here, or
on TUHS), and someone mentioned this paper:

  http://web.eece.maine.edu/~vweaver/papers/iccd09/iccd09_density.pdf

which shows that for a combo of benchmarks, the PDP-11 had the densest code
out of all the ones they looked at. (They didn't look at the PDP-8, but I
suspect that since it's a single-address design, it's almost ceertainly not
as dense.)

The PDP-11 dates back to the days of core (it went through several generations
before DRAM arrived - e.g. the -11/70 originally shipped with core), and given
core prices, minimizing code size was pretty important - hence the results
above.

So if you want to get the most bang out of 16K buck...

Not the simplest machine to implement, mind - the -8 is a lot simpler. Which
axis is the most important to you?

	Noel