I highly recommend the classic:

http://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/hardware/third-party-disks.txt

Doug


On Tue, 30 Jan 2001, NetBSD Bob wrote:

> Can someone explain how to use AT 1.2MB floppy drives on an RQDX3.
> I have this wilde hair that I want to try to load NetBSD or Ultrix
> from floppy as an aside on one of my MVII crates.  IFF the hardware
> is compatible, and I think it is, even though the floppy formats
> are incompatible with the old RX50 things, all I need to do is mate
> up a 34 pin dip header cable off the back of the backplane firewall?
> 
> What ID and jumpering is required?
> 
> Thanks
> 
> Bob
>