Subject: KFQSA Resolution - at last
To: Classic Computers <>
From: Chuck McManis <>
List: port-vax
Date: 07/29/1999 17:29:51
Hello everyone, 

The KFQSA has got to be one of the _weirdest_ boards DEC ever made to
control disks.

Some data points:

KFQSA Switch Table (Normal Operation)

    1   2   3   4  CSR Address in Octal
   --- --- --- --- -------------------------
   ON  ON  ON  ON  0760444 (Secondary TMSCP) < tape controller
   ON  ON  ON  OFF 0774500 (Primary TMSCP)   < tape controller
   ON  ON  OFF ON  0760334 (Secondary MSCP)  < Disk controller
*  ON  ON  OFF OFF 0772150 (Primary MSCP)    < Disk Controller

KFQSA Switch Table (When being programmed)
    1   2   3   4  CSR Address in Octal
   --- --- --- --- -------------------------
*  ON  OFF ON  ON  0774420 	(service 0)
   ON  OFF ON  OFF 0774424 	(service 1)
   ON  OFF OFF ON  0774430	(service 2)
   ON  OFF OFF OFF 0774434	(service 3)

To configure the board to support two DSSI drives as I have, you first put
the KFQSA into "service mode" (ON-OFF-ON-ON) then power cycle and at the
uVAX chevron type:

>>> set host/maintenance/uqssp/service 0

If you have correctly set the switches on the KFQSA it will respond with a
program :

UQSSP Controller (774420)


Node   CSR Address   Model
 0       760444       22
 1       760354       21
 2       760360       21
 6     ------ KFQSA ------
? help
    SET <node> /KFQSA                   set KFQSA DSSI node number
    SET <node> <CSR_address> <model>    enable a DSSI device
    CLEAR <node>                        disable a DSSI device
    SHOW                                show current configuration
    HELP                                print this text
    EXIT                                program the KFQSA
    QUIT                                don't program the KFQSA

    <node>                              0 to 7
    <CSR_address>                       760010 to 777774
    <model>                             21 (disk) or 22 (tape)

I enable two disk drives telling it that unit 1 is on the first controller
and unit 2 is on the second.

? set 0 772150 21
? set 1 760334 21

Now type 'EXIT' (and this saves that config) change the switches to select
primary MSCP (on-on-off-off) and restart.

Now the system powers up and shows two MSCP controllers (even though there
is just the one) and DUA0: is on one, and DUB1: is on the other. I don't
know if I can make both drives show up on one controller. That will require
a bit more experimentation.