SC(4)                   COMMAND REFERENCE                   SC(4)



NAME
     sc - raw SCSI interface

SYNOPSIS
     #include <sys/ioctl.h>
     #include <box/scsi.h>

DESCRIPTION
     The files /dev/scxy refer to devices on the SCSI bus, where
     x specifies the interface slot number (1 through 6) and y
     specifies the SCSI device (0 through D).  This provides for
     one or two drives (in SCSI parlance, logical units) on each
     of seven controllers.  (The SCSI interface itself uses
     controller address 7.) For example, sc57 refers to
     enhancement slot 5, controller 3, drive 1.

     There are three ioctls which send commands to the device.
     All three take the address of an sccommand structure
     (defined in scsi.h) as an argument.  The structure provides
     for up to twelve command bytes and a pointer to any data to
     be moved.  SCIOCCMD does not move any data; cmdarg and
     cmdcount are ignored.  SCIOCWCMD writes data to the device.
     SCIOCRCMD reads data from the device.  In each case, the
     driver will send the command to the device.  If the device
     returns BUSY status, the driver will continue trying
     indefinitely.  In such cases, it may be necessary to turn
     the SCSI device off or remove it from the bus to 'unhang'
     the driver.  When the command completes, the driver will
     return 0 (successful completion) or -1 (error).

RETURN VALUE
     If an error occurs, the call returns -1 and one of the
     following values is left in errno:

     [ENODEV]    You have attempted to access an interface or
                 device which doesn't exist.

     [EIO]       The SCSI command returned with a check status.
                 You should do a request sense command to find
                 the reason for the error.

CAVEATS
     There is no way to set the host interface address, share
     peripherals, or communicate between hosts.

     There is no way to access logical units 2 through 7.

     If a SCSI device hangs, it may be necessary to turn it off
     or unplug it from the SCSI bus to abort the command.

SEE ALSO
     ds(4), tc(4).



Printed 10/17/86  Engineering Computing Systems                 1

%%index%%
na:72,59;
sy:131,113;
de:244,1533;
rv:1777,503;
ca:2280,343;
se:2623,78;
%%index%%000000000106