SUMMARY: Pioneer CDROM DR-124X

From: Eduardo A. Suarez (esuarez@fcaglp.fcaglp.unlp.edu.ar)
Date: Mon Jan 27 1997 - 14:59:41 CST


Thanks to:

      Debande@smd.ucl.ac.be
      James.E.Coby.Jr@cdc.com (James Coby)
      bismark@alta.Jpl.Nasa.Gov (Bismark Espinoza)
      nadya@bog.ucsd.edu (Nadya Williams)
      kpischke@cadence.com (Karlheinz Pischke)
      Justin Young <justiny@cluster.engr.subr.edu>

============================================================================

From: nadya@bog.ucsd.edu (Nadya Williams)

The FAQ "subject 5.12 Why don't third-party CD-ROMS work on my sun?" says:

  When Sun first decided to add CD-ROM support, there were already a great
  number of systems in the field, all of which contained boot proms that
  expected to boot from disks with 512 byte sectors. Sun had to decide
  between replacing a whole lot of boot proms or finding a way to make a
  CDROM act like a disk with 512 byte sectors in order to support it as a
  boot device. They chose the latter approach.

  Many third party CD-ROM drives use 1024 or 2048-byte sectors, which causes
  the SCSI driver to see a "data overrun". When the driver asks for N
  "blocks" (which it thinks are 512 bytes each ) it gets more data back than
  it expected.

  Some CD-ROM drives can be told to use 512 byte sectors by setting a jumper,
  cutting a trace, or using a software command (mode select). Details vary
  widely, but if you are seeing a data overrun on a third party CD-ROM, then
  it is most likely doing 1K or 2K transfers and will need some work to be a
  boot device for a Sun.

  For more information about third-party CD-ROMS on Suns, consult the
  CD-ROM FAQ, which is posted periodically to comp.sys.sun.hardware.

============================================================================

From: kpischke@cadence.com (Karlheinz Pischke)

Take a look at the PIONEER documentation if sectorsize is selectable
from 2048 (usual at PCs) 512 Byte (usual at UNIX boxes).

If it's not selectable change FROM

/*
 * define for 512 bytes/sector
 */
#define FIVETWELVE

/*
 * set drive to read 2048 bytes per sector (default to 512 bytes/sector)
 * #undef FIVETWELVE
 */

TO

/*
 * define for 512 bytes/sector
 * #define FIVETWELVE
 */
 
/*
 * set drive to read 2048 bytes per sector (default to 512 bytes/sector)
 */
#undef FIVETWELVE

IN /usr/kvm/sys/scsi/targets/srdef.h

Then you have to make a new kernel !!!

============================================================================

  Facultad de Ciencias Astronomicas Eduardo A. Suarez
  y Geofisicas - UNLP
                                             esuarez@fcaglp.fcaglp.unlp.edu.ar
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  (1900) La Plata +54-21-526589 (part)
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                                                    Dave Clark
                                                       1992
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