README FOR LINUX SONY CDU-535/531 DRIVER
              ========================================

This is the sixth release of the Sony CDU-535 (and 531) driver for
Linux.  There are no new features or bug fixes in this release.
It just brings the patches up to the 1.1.45 Linux kernel.
I do not think I have the documentation to add features
like DMA support so if anyone else wants to pursue it or
help me with it, please do.  (I need to see what was done
for the CDU-31A driver -- perhaps I steal some of that code.)

IMPORTANT: If you are using *any* release of this driver prior to
           0.4, note that the device number has changed to 24 -- you
           will have to recreate your devices!  (see CHANGES)

This package contains a Linux device driver for the Sony CDU-535 CDROM
drive.  This is one of the older Sony drives with its own interface
card (Sony bus).  The DOS driver for this drive is named SONY_CDU.SYS
- when you boot DOS your drive should be identified as a SONY CDU-535.
The driver probably works with a CDU-531 also since that drive's
documentation was used to write the driver -- Sony said they were very
similar. One user reported that the driver worked on drives OEM'ed by
Procomm, drive and interface board were labelled Procomm.

The Linux driver is based on Corey Minyard's sonycd 0.3 driver for the
CDU-31A.  Ron Jeppesen just changed the commands that were sent to the
drive to correspond to the CDU-535 commands and registers.  There were
enough changes to let bugs creep in but it seems to be stable.  Ron
was able to tar an entire CDROM (should read all blocks) and built
ghostview and xfig off Walnut Creek's X11R5/GNU CDROM.  xcdplayer and
workman work with the driver.  Others have used the driver without
problems except those dealing with wait loops (fixed in third
release).  Like Minyard's original driver this one uses a polled
interface (this is also the default setup for the DOS driver).  It has
not been tried with interrupts or DMA enabled on the board.

REQUIREMENTS
============

	- Sony CDU-535 drive, preferably without interrupts and DMA 
	  enabled on the card.

	- Drive must be set up as unit 1.  Only the first unit will be 
	  recognized

	- Linux kernel source and gcc compiler

FILES
=====
	README		- this file
	sony535-0.6.patch - diffs to the kernel necessary for the driver that
			    may soon be part of the stock kernel
	sony535-0.6.files - more diffs to the kernel necessary for the driver
	CHANGES		- list of changes between this version and previous
			  versions of the driver

INSTALLATION
============

1. Untar the distribution someplace.  (Ok, so you've already done that.)
   For the examples below I assume that you untar into the /usr/src/sony535-0.6
   directory.

	cd /usr/src
	gunzip -c sony535-0.6.tar.gz | tar xvf -

2. Apply the patch files in the directory that holds the
   Linux source directory (normally /usr/src).  This is where you
   normally apply patches.  i.e., if Linux is in /usr/src/linux,
   apply the patch in /usr/src.

	cd /usr/src/linux
	make config.in
	cd ..
	patch -p0 <sony535-0.6/sony535-0.6.patch >& patch.log
	patch -p0 <sony535-0.6/sony535-0.6.files

   This will patch cleanly with the Linux 1.1.45 kernel.  If you have
   applied other patches check patch.log to see if any of the patches
   failed.  If they did, you will have to make the changes by hand.

3. If your Sony interface card is not at the default address of 0x340,
   you will have to modify the file linux/drivers/block/sonycd535.c, 
   changing the CDU535_ADDRESS define on line 122 to the address on
   your board.  If you are not sure of your board address, check
   the documentation and jumpers or check your CONFIG.SYS file
   under MSDOS. In CONFIG.SYS, the address is given using the /B parameter
   to the SONY_CDU.SYS driver (except don't put the 'H' at the end).  Enter
   the same number in hex (put 0x in front of the number).

4. Make a device with major number 24, minor number 0.  Use the command:

	mknod /dev/cdu535 b 24 0

   Then create a symbolic link from /dev/cdu535 to /dev/cdrom:

		ln -s cdu535 /dev/cdrom

   This link will allow SCSI and Sony drive to be handled with the same
   drivers.  Minyard wrote the Sony driver to have the same IOCTL interface
   as the SCSI driver, so commands should work fine on both.  If you
   want to run something that expects a SCSI CDROM drive, create a
   symbolic from /dev/cdu535 to /dev/sr0 (useful for workman)

	rm /dev/sr0
	ln -s cdu535 /dev/sr0

5. Reconfigure the kernel (make config) and answer "y" to the Sony CDU-535
   CDROM prompt.  Make sure you also answer "y" when it asks if you want 
   the ISO9660 filesystem.  This is the filesystem used by CD-ROMs.  Do a 
   "make dep", "make clean", then rebuild the kernel ("make").  Make a
   boot floppy using the command "make zdisk" (make sure a new floppy
   is in the A: drive).

6. Reboot and try it out.  If all goes well you will get a message
   during startup saying that the Sony CDROM drive was found.  The command 
   to mount a CDROM is:

	mount -r -t iso9660 /dev/cdrom /cdrom

   (Make the directory /cdrom first if it does not already exist.)

NOTES:
======

1) The drive MUST be turned on when booting or it will not be recognized!

2) when the cdrom device is opened the eject button is disabled to keep the
   user from ejecting a mounted disk and replacing it with another.
   Unfortunately xcdplayer and workman also open the cdrom device so you
   have to use the eject button in the software.  Keep this in mind if your
   cdrom player refuses to give up its disk -- exit workman or xcdplayer, or
   umount the drive if it has been mounted.

THANKS
======

Many thanks to Ron Jeppesen (ronj.an@site007.saic.com) for getting
this project off the ground.  He wrote the initial release and
the first two patches to this driver (0.1, 0.2, and 0.3).

(aknowlegements from Ron Jeppesen in the 0.3 release:)
Thanks to Corey Minyard who wrote the original CDU-31A driver on which
this driver is based.  Thanks to Ken Pizzini and Bob Blair who provided 
patches and feedback on the first release of this driver.

Ken Pizzini
ken@halcyon.com