VAX-VMS DSSI Notes:

Menu: Basic DSSI 3500 | Basic DSSI 4300 | DSSI based VAXcluster | KFMSA | KFQSA

Basic DSSI Storage Example (uVAX-3500)

+-----------------+
| uVAX-3500       |
| CPU             |
+-----------------+
| Q-Bus Adapters  |       +---------------------+
| KFQSA   +-------x-------x DSSI Bus #0 Devices x- DT/e
| DSSI#0--+--DT/i |       +---------------------+
|                 |
| KZQSA   +--A----x-ST/e  +---------------------+
| SCSI#0--+--B----x-------x SCSI Bus #0 Devices x- ST/e
|                 |       +---------------------+
+-----------------+
 
Legend:
DSSI#0 = Optional Q-Bus/DSSI Controller (KFQSA)
SCSI#0 = Optional Q-Bus/SCSI Controller (KZQSA)
DT/i   = DSSI Bus Terminator Internal
DT/e   = DSSI Bus Terminator External
ST/e   = SCSI Bus Terminator External
 
Notes:
1. every DSSI port must be connected to either a DSSI terminator or a DSSI cable
   which is connected to one or more DSSI devices with a termination at the end
   of the chain.
2. to the best of my knowledge, the internal DSSI terminators cannot be
   removed.
3. whether physically visible or not, there is always a terminator at each end of
   both DSSI and SCSI busses.

Basic DSSI Storage Example (uVAX-4300)

+-----------------+
| uVAX-4300       |       +---------------------+
| CPU     +-------x-------x DSSI Bus #0 Devices x- DT/e
| DSSI#0--+--DT/i |       +---------------------+
|                 |
| DSSI#1--+--A----x-DT/e  +---------------------+
|         +--B----x-------x DSSI Bus #1 Devices x- DT/e
| Internal Bus    |       +---------------------+
+-----------------+
| Q-Bus Adapters  |       +---------------------+
| KFQSA   +-------x-------x DSSI Bus #2 Devices x- DT/e
| DSSI#2--+--DT/i |       +---------------------+
|                 |
| KZQSA   +--A----x-ST/e  +---------------------+
| SCSI#0--+--B----x-------x SCSI Bus #0 Devices x- ST/e
|                 |       +---------------------+
+-----------------+
 
Legend:
DSSI#0 = Embedded DSSI (SHAC) controller #0
DSSI#1 = Embedded DSSI (SHAC) controller #1
DSSI#2 = Optional Q-Bus/DSSI Controller (KFQSA)
SCSI#0 = Optional Q-Bus/SCSI Controller (KZQSA)
DT/i   = DSSI Bus Terminator Internal
DT/e   = DSSI Bus Terminator External
ST/e   = SCSI Bus Terminator External
 
Notes:
1. DSSI#1-A may connect to more DSSI Bus #1 devices, or to the DSSI bus of
   another CPU (if both CPUs are part of a VAXcluster)
2. every DSSI port must be connected to either a DSSI terminator or a DSSI cable
   which is coonected to one or more DSSI devices with a termination at the end
   of the chain.
3. to the best of my knowledge, the internal DSSI terminators cannot be
   removed.
4. Wether physically visible or not, there is always a terminator at each end of
   both DSSI and SCSI busses.

DSSI Based VAXcluster Example

+----------+ +------+------+------+------+------+------+ +----------+
| CPU 0    | | RF72 | RF72 | RF71 | RF71 | RF71 | TF70 | | CPU 1    |
| DSSI-0---+-+ A0   | A1   | A2   | A3   | A4   | A5   +-+---DSSI-0 |
|          | +------+------+------+------+------+------+ |          |
|          |   DS0    DS1    DS2    DS3    DS4           |          |
|          | +------+------+------+------+------+        |          |
| DSSI-1---+-+ RF72 | RF72 | RF71 | RF71 | RF71 +--------+---DSSI-1 |
| Internal | | B0   | B1   | B2   | B3   | B4   |        | Internal |
+----------+ +------+------+------+------+------+        +----------+
| Q-Bus    | +------+------+------+------+------+------+ | Q-Bus    |
|          | | RF71 | RF71 | RF71 | RF71 | RF71 | RF71 | |          |
| DSSI-2---+-+ C0   | C1   | C2   | C3   | C4   | C5   +-+---DSSI-2 |
|          | +------+------+------+------+------+------+ |          |
|          |   DS6    DS7    DS8    DS9    DS10          |          |
|          | +------+------+------+------+------+------+ |          |
| DSSI-3---+-+ RF71 | RF71 | RF71 | RF71 | RF71 | RF71 +-+---DSSI-3 |
|          | | D0   | D1   | D2   | D3   | D4   | D5   | |          |
+----------+ +------+------+------+------+------+------+ +----------+
Legend:
RF72  = 1 Gigabyte Hard Drive
RF71  = 350 Megabyte Hard Drive
TF70  = Cartridge Tape
DS    = Disk Shadow (example: DS0 is a shadow set volume composed of mirror
        disks A0 and B0. If one of the drives crash, the mate drive can carry on
        independently). This requires an optional "Shadow License".
Notes:
1. A "Cluster License" must be installed in order for the CPUs to cooperate
   with each other in this configuration.
2. CPU-CPU communication can take place on either a shared ethernet or one of
   the DSSI busses.

XMI-DSSI Adapter (KFMSA)

  +-+-- unused DSSI termination (parking) sockets
  | |
  V V
+--------------------------------+
| x x                            |
| x x                            |
| x x                            |
|                                |
| x x                            |
| x x                Bus     +-+---- DSSI termination sockets
| x x                Driver  | | |
|                    Chips   V V |
|                   +------+     |
|                   |      | x x |
|                   |      | x x | DSSI #0 (jack 1) connects here
|                   |      | x x |
|                   +------+     |
|                   +------+     |
|                   |      | x x |
|                   |      | x x | DSSI #1 (jack 2) connects here
|                   |      | x x |
|                   +------+     |
+--------------------------------+
Notes:
1. Make sure that the terminations are in the lower right position (some people
   are convinced that they are not required, this is false)
2. Diagnostic + Configuration programs (must boot VAX/DS)
   - EXSBA diagnostic supervisor
   - EVRAE online DSSI disk exerciser
   - EVMDA online DSSI tape exerciser
   - EVCXD repair level diagnostic
   - EVCXE ISE drive configuration (VAX-6000 series only)
   - EVCXF DSSI configuration and DUP diagnostic

Q-Bus/DSSI Adapter (KFQSA)

+--------------------------------+
| xx                             |
| xx                             |
| xx                             |
| xx                             |
| xx                             |
| xx                             |
| xx                             |
|                                |
|                                |
| +----+                         |
| |1234| Switch Pack             |
| +----+                         |
|                                |
|                                |
|                                |
|                                |
|                                |
|                                |
+--------------------------------+
Switches:
1 2 3 4
- - - -
1 x x x CSR addresses are read from EEPROM 
 
0 1 0 0 CSR = 17774420 (a.k.a. service #0)
0 1 0 1 CSR = 17774424 (a.k.a. service #1)
0 1 1 0 CSR = 17774430 (a.k.a. service #2)
0 1 1 1 CSR = 17774434 (a.k.a. service #3)
| | | +------ LSB
| | +-------- MSB
| |
0 0 0 0 CSR = 17760444 tape (secondary)
0 0 0 1 CSR = 17774500 tape (primary)
0 0 1 0 CSR = 17760334 disk (secondary)
0 0 1 1 CSR = 17772150 disk (primary)
| | | +------ 1=primary 0=secondary
| | +-------- 1=disk    0=tape
| +---------- 1=fixed   0=floating
+------------ 0=service 1=normal
 
Notes:
This adapter is programmable from the console as follows:
1. Set the adapter DIP switches to force the module into service mode and the
   CSR (Control + Status Register) base address into the fixed area.
2. Make sure the system console can see the module in service mode
   <sr> >>>
   <ur> sho qbus
   <sr> 772150 KDA50            (this MSCP adapter is the primary disk)
        772140 TQK70            (this is a TK70 cartridge tape controller)
        774420 KFQSA Service #0 (this DSSI adapter is in service mode #0)
   <sr> >>>
3. <ur> set host/uqssp/maintenance/service 0
   <sr> UQSSP Controller (774420)
        Enter SET, CLEAR, SHOW, HELP, EXIT, or QUIT
        Node     CSR Address     Model
        7        -------- KFQSA ------
   <sr> ?
   <ur> set 0 760334 21         (DSSI id #0, secondary device, 21=disk)
   <sr> ?
   <ur> set 1 760340 21         (DSSI id #1, tertiary device, 21=disk)
   <sr> ?
   <ur> show
   <sr> UQSSP Controller (774420)
        Enter SET, CLEAR, SHOW, HELP, EXIT, or QUIT
        Node     CSR Address     Model
        0        760334          21
        1        760340          21
        7        -------- KFQSA ------
   <sr> ?
   <ur> exit
   <sr> Programming the KFQSA ...   <sr> >>>
4. Now throw DIP switch #1 to put the adapter into normal mode
5. <sr> >>>   <ur> sho qbus   <sr> 772150 KDA50            (this MSCP adapter is the primary disk)
772140 TQK70            (this is a TK70 cartridge tape controller)
774420 KFQSA Service #0 (this DSSI adapter is in service mode #0)
   <sr> >>>   
   Notes: in this example,
   1. when the card is moved back to the non service position it will respond as
      if 3 KDA-50 disk adapters have been installed on the Q-Bus
   2. the card is using DSSI id #7

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Neil Rieck
Kitchener - Waterloo - Cambridge, Ontario, Canada.