4.3 UDA50 problem with RA80

[Chris Torek]

In article <383 at hsi.UUCP> stevens at hsi.UUCP (Richard Stevens) writes:
>We just brought up 4.3 BSD on an 11-785 with a UDA50 with
>one RA80 (drive 0) ... newfs tries to mkfs with a size of
>111,202 sectors.  Mkfs very quickly bombs with the message
>
>	endcd=200, stat=16001
>
>Comments in the driver indicate that this is probably a response
>to an invalid command, with some mention of invalid block numbers.

Code 0200 is M_OP_END.  According to the MSCP documentation that
I have never seen, this is given only in response to an invalid
command.  According to much more reliable legend, this is also
given in response to an attempt to write too far past the end of
the disk.  According to established fact, an attempt to write a
little past the end of an RA81 will write on the bad sector
replacement information; the UDA50 driver is supposed to avert
this kind of disaster, and I can only guess that the distributed
4.3 partition tables are wrong.

>Anyone know whats going on ??  By the way, I looked at the driver's
>udamicro variable and it contained 0x4063 which indicates a microcode
>level of Version 3, model 6, if thats of any use.

DEC is up to version 5 model 6, at least (we have two such).
Version 3 still has the Get Unit Status microcode hang bug, I
believe.  Of course, it is practically impossible to get any reliable
information on UDA50s and MSCP out of DEC.  Rumour has it that this
is because DEC `accidentally' sold such to various competitors,
and decided this was a bad idea.  If so, I cannot see why they do
not simply require a nondisclosure/noncompetition agreement before
selling the documentation.

Until DEC starts selling MSCP documentation---under whatever
strictures---I will continue to recommend against buying any of
their products that use it.  (I would recommend against RA81s
anyway.  Eagles are reliable, almost as large, less expensive, and
faster; and DEC will service them.)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 1516)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at mimsy.umd.edu