Introduction and need help bringing some pdp11's back

[allison]

On 10/29/19 2:13 PM, Pete Turnbull via cctalk wrote:
> 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!
> 

I assume your building up a Qbus PDP-11.

To go from RQDX3 to any drive you need a distrbution panel as used in
BA23 or M9058 distribution board usually used in BA123.

The M9058 can plug in to any general slot in Qbus for power and does not
past interrupt or DMA grant.  Bottom/end of the bus is fine.

Then you need a 50 wide cable from RQDX3 to the distribution board and
the cable to match floppy from the distribution board (usually 34 wide).

FYI that combo works with RX50, RX33 (teac FD55GFR) , and RX23 (3.5"
floppy).

The most desirable drive is the RX33 as it stores more and faster
plus makes it easier to write a disk from a PC.

Jumper details are up to  you to slug out but I have two systems using
the RQDX3 and M9058.  I also have the Micro PDP-11 using the ba23
distribution.   Don't ask right now I can not get to them for the next
month.  Drive jumpers have to be correct.

If the cables are upside down you break nothing but noting works.
Hint flip only one end!

All of this is in the various manuals but no single one!

Allisonn