ST-01 SCSI controller jumper settings

[Tatu Yl|nen]

umbc3!tron!beser at uunet.uu.net was asking about the jumpers on the ST-01
controller.  I will post my answer to comp.unix.microport, as this
may be of interest to others as well.

----------

Here is a picture of the card.

  +--------------------------------------------+
  I   ::::::::::::::::::::::::::::::::::::     I +--
  I     (50-pin scsi connector)                I I
  I                                         +----I
  I                                         +----I
  I   +----+                 +--+              I I  (mounting bracket)
  I   I    I    +-----+      I  I              I I
  I   I    I    I     I      I  I              I I
  I   I    I    I     I      I  I              I I
  I   +----+    +-----+      +--+              I I
  I                                            I I
  I      E  F           A  B                   I I
  I       ..             ..    .            +----I
  I        .             ..    . (0ws)      +----I
  I         G           C  D                   I I
  +-+  (intr en. jumpers) (bios addr j.)   +---+ I
    I IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII I     I
    +--------------------------------------+     I
             (edge connector)                    I

Memory address

no jumpers installed       CA000H  (default setting)
pins C-D shorted           C8000H
pins A-B shorted           CE000H
pins A-B & C-D shorted     DE000H

The memory address set on the card must match the value defined in the driver.
Check the driver source for the correct address.  If you want to use a
different address, change the define in the source.


Interrupt selection

No jumper installed       interrupts disabled (default configuration)
E-F shorted               IRQ3
F-G shorted               IRQ5

Interrupts must be enabled to use my driver under unix.  The interrupt
selected must match the value in file "config" in the modules/scsi
directory.  Check the config file for the correct value; change the value
in config file if you wish to use some other value.

NOTE: at least in the card I received, there were no jumper connectors
in E, F and G.  There were just holes in the card.  You have to solder the
connection yourself.  It is not a difficult task if you have ever done
any soldering, and luckily the card does not cost very much if something
goes wrong...  It is better to ground the soldering iron before doing 
anything.

If I recall correctly, I am using IRQ5, and soldered F&G together with a
short wire.  A friend of mine had both of those interrupts in use,
and soldered F to some other interrupt number on the bus and everything
works fine.  However, I can't help with that.  For more info, see
IBM AT technical manual.  (You might get some help by sending mail to
jnopanen at hupu.hut.fi).

It seems like Seagate has been thinking that the controller would never
be used with unix...


I think the 0ws jumper should be connected on most (almost every?)
machines.  On my machine it raised the transfer rate from about 500kB/sec
to about 700kB/sec under msdos.  The transfer rate is really cpu-bound
as the data transfers are done in software (the card does not support
dma), so faster machines might get faster transfer rates (mine is a slow
16 MHz 386).

  Tatu Yl|nen    ylo at hupu.hut.fi