[comp.periphs] CDC PA5N1B

rbrode@nmsu.edu (Rick Brode) (04/16/91)

Several weeks ago I posted:

>We recently ripped a CDC PA5N1B disk drive out of a dead symbolics and 
>are attempting to install it on a Sun 3/160 running Sunos 4.1.  The PA5N1B 
>is a 515 MB SMD drive.   We are attaching it to a Xylogics 450 controller 
>in the Sun.    There are twelve dip switches on the control board inside
>the disk drive which need to be set according to the "number of sectors".
>However, I can't find anywhere in the 450's documentation what the value
>for "number of sectors" should be.
>
>Does anybody have this configuration and would be able to supply this little
>tidbit of information?   Any other gotchas that people know about would 
>be appreciated.

Well, we finally got it formatted.  A techie from Xylogics was able to
supply the appropriate switch settings which equated to 48 sectors,
assuming a .8 MHz clock and the round-down method for computing sectors.
Our format.dat entry looks like:

disk_type = "CDC PA5N1B" \
        : ctlr = XY450 : fmt_time = 4 \
        : ncyl = 709 : acyl = 2 : pcyl = 711 : nhead = 24 : nsect = 47 \
        : rpm = 3600 : bpt = 30240 : bps = 600 : drive_type = 1

I should note that we ended up installing it on a 451 because the Sun was
giving an "unsupported controller type" error message during bootup with
the 450 (although Sun says that the 450 is still supported under 4.1.  Does
anybody out there have a Xylogics 450 installed in a Sun running 4.1?).

Also, the PA5N1B is equivalent to the Seagate 9715-515.  Only the names
were changed to protect the innocent.

Special thanks to the people who responded via e-mail and the phone
with helpful suggestions and to the tech support people at Seagate, Sun,
and Xylogics who spent a lot of time helping me out.

Rick Brode
Computing Research Lab
New Mexico State University
rbrode@nmsu.edu