Browse Prior Art Database

Customization of Direct Access Stroage Device Features with a Single Read Only Storage/Random Access Memory Microcode

IP.com Disclosure Number: IPCOM000114324D
Original Publication Date: 1994-Dec-01
Included in the Prior Art Database: 2005-Mar-28
Document File: 2 page(s) / 73K

Publishing Venue

IBM

Related People

Dervin, JM: AUTHOR [+3]

Abstract

Disclosed is a method of providing vendor unique customization of Direct Access Storage Device (DASD) features without the need for multiple Read Only Storage (ROS)/Random Access Memory (RAM) microcode loads. The customization is accomplished with a single load of ROS/RAM microcode.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Customization of Direct Access Stroage Device Features with a Single
Read Only Storage/Random Access Memory Microcode

      Disclosed is a method of providing vendor unique customization
of Direct Access Storage Device (DASD) features without the need for
multiple Read Only Storage (ROS)/Random Access Memory (RAM) microcode
loads.  The customization is accomplished with a single load of
ROS/RAM microcode.

The customization is done in two pieces:
  1.  ROS Customization - This is customization that is done
       immediately when power is applied to the file and before the
       motor is started.
  2.  RAM Customization - This is customization that is done after
the
       motor is spun up and the reserved area data is read.

      The ROS customization is done by using five sets of pins and
jumpers.  Four sets of pins determine customization while the fifth
pin set is used to determine if a file is generic or customized.
This fifth set is referred to as the Customized File Pin (GFP).
  o  GFP not Jumpered - This is a generic file, the four remaining
      pins can be used by the customer to determine certain file
      behavior such as:
     -  Disabling synchronous negotiations.
     -  Disabling Small Computer System Interface (SCSI) parity.
  o  GFP Jumpered - customization pins determine a customer id.
      Additional pins can be added to expand this to five, six of
more
      bits if more customer IDs are needed.  With GFP jumpered, the
      customer id is used as an index into a customization table in
      ROS.  This table is an array consisting of sixteen tables
      identical in structure that contain the customization data for
      various customers.  Examples of the data are:
     -  26 bytes of Inquiry Data corresponding to bytes 8-33 of the
         standard Inquiry Data.
     -  Bit defined functions such as:
        -  Amount of auto start delay in 2 second increments (3
bits).
        -  Disable synchronous/wide negotiations by target (1 bit).
        -  No unit attention on Power-On Reset (POR)/SCSI reset.  (1
            bit).
        -  Disable SCSI parity.  (1 bit).
     -  Additional bytes of spares are reserved for future
      ...