12 Sep
2004
12 Sep
'04
9:31 p.m.
Turn the problem around - the PDP-8/S has a backplane
that is approximately
16" x 30" with over 100 Flip Chips. If you were to attempt to turn that
particular design into a single planar board of the same size, the contents
of each Flip Chip would have to fit into the same square area as one back-
plane slot (about 0.5" x 3.5").
The PDP-8/s seems dense, but it is mostly air! While DEC made some nice
architectures, their mechanical people were a little behind the times. The
integration density of those old Flip Chips is pretty horrible, compared
with most other computer manufacturers. Think of the precentage of those
100+ Flip Chips that is blank board.
I am sure you could get a PDP-8/s come onto a 12 by 12 board, but I bet
that would be one expensive assembly!
William Donzelli
aw288(a)osfn.org