View source for CDU-710/M disk controller

The '''CDU-710/M''' is a [[UNIBUS]] [[SCSI]] disk controller made by [[CMD Technology Inc.]]. It fits in a [[DEC card form factor|quad]] [[Small Peripheral Controller]] slot. It support's [[DEC]]'s [[Mass Storage Control Protocol]].

==4.3BSD Quasijarus bootstrap bug==

When booting [[4.3 BSD Quasijarus]], there is a bug (although 
[[VMS]], [[NetBSD]] revisions above 1.6 or so, and [[Ultrix-32]] all boot fine); it hangs inside udcmd() in sys/vaxstand/uda.c.

The fix is to change line 155 from:

     if(u->uda_ca.ca_rspint == 0)

to:

     if(u->uda_ca.ca_rspdc & MSCP_OWN)

Re-build the bootstrap, and then run [[disklabel]] to update the copy on the disk.

==External links==

* [http://bitsavers.org/pdf/cmd/CDU-710_Brochure.pdf Brochure]
* [https://github.com/abs0/4.3BSD-Quasijarus 4.3BSD-Quasijarus with fixes on github]
* [http://www.classiccmp.org/pipermail/cctalk/2017-January/030798.html 4.3BSD boot bug]

[[Category: UNIBUS Storage Controllers]]
[[Category: SCSI]]