On 29/10/2019 16:28, Chris Zach via cctalk wrote:
The real problem is I'm trying to put an RQDX3 in there instead of the
ESDI controller so I can boot off RX50's. And I have no idea which way
all the various ribbon cables are supposed to go. Will any 50 pin cable
work between the RQDX3 and the BA23 distribution bulkhead? Anything
special about the 34ish pin cable that goes between the bulkhead and the
RX50? So far when I try to boot all devices DU0-3 give me not yet ready.
Welcome back!
No, there's nothing special about either the 50-way ribbon cable or the
34-way ribbon cable. Just don't use a PC-style floppy cable with a
twist in it. DEC did it the way God (and Alan Shugart) intended. But
which distribution bulkhead have you got? I assume not an M9058,
because that's a card with lots of options that goes in a Q-bus
backplane and wants jumpers setting.
Either way, you might find this file helpful if you want to work out
what's going where:
http://www.dunnington.info/public/RQDX/RQDXn_pinout.pdf
and maybe even a glance at this one:
http://www.dunnington.info/public/RQDX/M9058_schematic.pdf
because it shows the relationship between the connectors and the signals
a bit better.
--
Pete
Pete Turnbull
