Category : OS/2 Files
Archive   : SPB506.ZIP
Filename : IBM1S506.TXT

IBM1S506 Beta Driver Documentation
----------------------------------


Enclosed is the IBM1S506.ADD. It contains a number
of changes from the previous driver. This note is
intended to help explain those changes.


Summary of Changes
------------------

Multiple Controller support

- 2 independent controllers can be supported per instance
of this driver.

- Multiple instances of the driver may be loaded


Improved Geometry Support and >1024 Cyl support

- The driver will attempt to determine drive geometry
by the following methods:

-- Via command line switches
-- Via an IDENTIFY command issued to the drive
-- Via the Fixed Drive Tables

This driver will support disks >1024 cylinders
if indicated by one of the above geometry sources.

- The driver can display the BIOS (Int 13), IDENTIFY,

Command Line geometries and the geometry selected
by the driver.


Error Handling/Recovery

- The driver no longer issues "Power Management"
commands.

Regardless of what CAM states there appears to
be no industry wide consensus on what these commands
should be. In addition sufficient attention has
not been paid to compatibility issues with older
MFM/RLL and IDE controllers.


- Error recovery is driven by elapsed time

Error recovery in this driver has been restructured.
When an error occurs, retries will be done periodically
over a set time interval. This should allow drives which
have "spun-down" to recover.

- Soft-Reset used to help clear error conditions

The driver will issue a soft reset via 3F6 to recover
from timeouts and from persistent error conditions.


- Compatibility of external IDE adapters with PS/2 chip sets

PS/2 chip sets provide an integrated IDE port. This
driver will detect of an external IDE adapter is
present prior to enabling the internal PS/2 IDE
ports.



Command Line Switches
---------------------

Sample Command Lines:

BASEDEV=IBM1S506.ADD /V /A:0 /U:0 /T:10 /GEO:(1314,7,26,-1) /A:1 /I

BASEDEV=IBM1S506.ADD /V /A:1 /P:120 /IRQ:11 /U:0 /T:10

BASEDEV=IBM1S506.ADD /V /A:1 /U:0 /GEO:20

BASEDEV=IBM1S506.ADD /V /A:0 /U:0 /SMS

BASEDEV=IBM1S506.ADD /V /A:0 /!R


Switch definitions:

/V = Verbose Mode

Displays controller status and drive geometry information
during OS/2 initialization.


/A:0 = Adapter number

Adapter 0 has default parameters for a primary adapter.
Adapter 1 has default parameters for a secondary adapter.


/U:0 = Unit Id

Unit 0 indicates parameters apply to the master unit.
Unit 1 indicates parameters apply to the slave unit.


/T:10 = Error retry time in seconds. (dec)

Indicates the total allowable error recover time for
a request. Error recovery times < 5 seconds will be
ignored. This parameter defaults to 30 seconds. A shorter
interval may be desirable for fault tolerant applications.


/GEO:(1314,7,26,-1) or /GEO:20 = Drive geometry override (dec)

Indicates the Cylinder/Head/Sector geometry for the drive.
The fourth parameter is the Write Precompensation Cylinder
which may be omitted for drives which do not require
precompensation.

As an alternate format standard BIOS drive types may
be used. Types (0-47) are supported. User defined types
48, 49 should be entered directly by in the previous
format.

When specified, this parameter overrides other geometry sources.
If this parameter is absent, other geometry sources discussed
above will be used.


/I = Ignore adapter

The driver automatically attempts to locate and initialize
both the primary and secondary adapters. In some cases other
DASD controllers may appear between the primary and secondary
IDE controllers. In these cases the system should be configured
as follows:

BASEDEV=IBM1S506.ADD /V /A:1 /I
BASEDEV=MOREDASD.ADD
BASEDEV=IBM1S506.ADD /V /A:0 /I


/!R = Disable adapter resets

Disables adapter resets. In most cases resets are beneficial
to assist in recovering from transient hardware problems
such as lost interrupts, timeouts, or commands a particular
adapter may not support.

However, for some ESDI adapters, options set by vendor
unique commands such as 'Sector Sparing' may be lost after
after a reset. Setting this switch is recommended for ESDI
adapters with disks formatted using 'Sector Sparing'.


/P:120 or /PORT:120 = Base Port address (hex)

Overrides the default Base Port address for this adapter.
Ports are still assigned in this case would be (120-127) and
(326). The default port addresses for Adapter 0 is (1F0) and
for Adapter 1 is (170).


/IRQ:11 = IRQ Number (dec)

Overrides the default IRQ Number for this adapter. The default
IRQ address for Adapter 0 is (14) and for Adapter 1 is (15).


/SMS = Enable Set Multiple Mode support

This switch enables Set Multiple Support which the improves
performance of some IDE drives. If the drive does not have
this feature, this switch will be ignored. The /V - (Verbose)
option will indicate whether this feature has been enabled
on a particular drive.