21 Dec
2018
21 Dec
'18
9:08 a.m.
On 12/21/2018 07:19 AM, Noel Chiappa via cctalk wrote:
Yes, PDP-5 and DEC LINC were made with "System Building
Blocks", similar in technology to the board pictured, but
single-width and wrapped in an aluminum frame, with a blue
connector hand-wired to one end. Single-sided,
paper-phenolic PCBs.
Kind of similar to half of the board in the picture. I
think this same technology was used in a number of other
machines. Discrete transistors, diode-steered
capacitor-coupled FFs, really ANCIENT technology.
The "classic" PDP-8 was built with basically the same
circuit technology, but on smaller, unframed glass-epoxy
PCBs with etched and gold-plated card-edge fingers, with
color-coded handles indicating what technology was on it.
So, basic logic was R with red handles, memory boards
(select, read amp, etc.) were G with green handles, etc.
Jon
From: Mattis
Lind
I cannot figure out which early machine it comes
from.
They're called 'System Modules':
http://gunkies.org/wiki/System_Module
and they were used from the PDP-1 through (I think) the PDP-7; at least, this
PDP-7 internals image:
https://www.soemtron.org/images/jpgs/decimages/sn113robertjohnson85680004.j…
seems to show System Modules at the top, and FLIP CHIPs at the bottom. (I'm
pretty sure even the first PDP-8 - the 'straight 8' - uses only early FLIP
CHIPs - transistorized ones.)
The DEC brochure for it (P5141) is a little puzzling; it says (p. 2) that
"INTEGRATED CIRCUITS are basic elements of the low cost, newly designed
silicon FLIP CHIP modules used throughout PDP-7", but AFAIK, the first FLIP
CHIPs (R-series, B-series, etc) were all transistors; the later M-series were
the first ones to have ICs. Maybe this is some old meaning of "integrated
circuits"?
