8 Feb
2016
8 Feb
'16
1:18 p.m.
On Feb 8, 2016, at 1:08 PM, Ian S. King <isking at
uw.edu> wrote:
I?m not a particular fan of that because some of the signals I?m running are
pretty fast between the FPGA and some of the other components (~40ns
cycle time for the FRAMs for example). I wouldn?t want to run those signals
very far and certainly not across any sort of cabling.
It?s not clear to me (yet) how I could partition the design across 2 SPC boards.
TTFN - Guy
See above re: gold edge fingers. I was originally thinking that if I do
have to
split the board up, that I?d make them completely independent. But that
has
the issue of requiring 2x the number of UNIBUS transceiver parts (which are
all but unobtainium as of now). One of the things that drives up the
power (and
board area) are said transceivers (and level shifters, etc). If I could
come up
with a reasonable alternative for the SPC version, that may work. But
that?s
all in the future at the moment.
TTFN - Guy
A thought: would a second quad board necessarily need transceivers? I'm
thinking of the top-block connectors used in the PDP-8, and the top-plugged
ribbon cables for e.g., MicroVAX II CPU-to-memory connection. You might
still want to grab power through a few fingers, but that's an
implementation detail. ? Ian