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1981-06-29
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216 lines
Welcome to a4000_atapi.device by Elaborate Bytes!
Copyright © 1994, 1995 Elaborate Bytes, Oliver Kastl
GENERAL
This device allows you to use an ATAPI CD-ROM drive
with the A4000 or A4000T embedded IDE controller.
A4000 users can use the very popular and cheap CD-Roms for PCs
without any major disadvantages against SCSI CD-Rom drives.
The major advantage for A4000 users without a SCSI controller
is, that they don't have to buy one.
The major advantage for A4000 users with a SCSI controller
is, that they have an unused IDE port in their machine anyway
and SCSI CD-Roms are usually more expensive.
The device maps SCSI-II commands to ATAPI packets using the
standard Commodore HD_SCSICMD interface, so any "CD-Rom
specific" programs (Multisession Filsystems, Audio Players and
Photo-CD readers) designed for SCSI-II CD-Roms should work.
This has been tested with CacheCDFS, PlayCD, CD32-Emulator
(all written by me) and PhotoWorX (an excellent PhotoCD Reader
by Corporate Media).
However, I cannot guarantee that every SCSI-II specific program will
work, but I do not expect any major problems.
The device is fully interrupt driven and will use only a small
amount of CPU time for the transfer (exceptions are listed below).
COMPATIBILITY WITH EXISTING IDE HARDDISK
Every (and I mean it!) IDE drive that works with the original
Commodore scsi.device WILL continue to work if the a4000_atapi.device
is installed. The reason is simple: My device will use the code of the
Commodore scsi.device (if present) to access the IDE harddisk.
If you connect an ATAPI CD-Rom and you harddisk stops to work, this
usually is a hardware, not a software problem.
Check cables & jumpers.
Some harddisks must be rejumpered, if a slave drive is connected.
Consult the manual that came with your harddrive before doing so
or ask your dealer for assistance.
Make sure, the CD-ROM is configured as a slave device.
Some CD-Roms (e.g. the Wearnes CDA-120) have an option to enable or
disable interrupts. As the a4000_atapi.device is interrupt driven to
reduce CPU use, it will NOT work if you disable interrupt generation
on the CD-Rom drive.
Please consult the CD-Rom installation manual.
USING MORE THAN TWO UNITS
Starting with version 6.x, a4000_atapi.device is able to support up to
4 units. This may be up to two harddisks or any number of CD-Roms.
For this feature to work, you need a special cable which has one connector
for the Amiga IDE port and four connectors for different IDE units.
This cable will be shortly available from official Elaborate Bytes
distributers.
This cable will in fact add a "second" full operational and independend
IDE port to the system. (WOW! How is this possible? I would really love
to share this secret, but I am not allowed to tell :-)
Connecting the CD-Rom to the "second" IDE port will effectively hide
the CD-Rom from Commodore's scsi.device during boot.
As a side effect this eliminates any problems which could be caused
by the scsi.device which may be confused by the presence of a CD-Rom.
Connecting the CD-Rom to the "second" port will eliminate any possible
master/slave problems with existing harddisks.
A600 & A1200
Support for A600 and A1200 has been added. The device is called
"a1200_atapi.device" and will work with both machines.
You should use the SetAtapiSpeed command to maximize the CD-Rom performance.
Using more than two units is not possible with the A600.
TESTED DRIVES
A couple of drives have been tested with the a4000_atapi.device.
The test configuration was an A4000/40 with and without Oktagon 2008
SCSI controller, with and without an IDE Harddisk (Quantum Maverick 540
or Seagate ST328A). The drives were selected always as the slave device,
even if no IDE Harddisk was installed.
Recommended drives (work 100%):
Mitsumi FX-001DE (2x speed)
(Don't mix this up with the FX-001D! The FX-001, FX-001D and LU005
are NO atapi devices and will NOT work! Connecting a non IDE/ATAPI
device to the Amiga IDE port may damage both your Amiga and your CD-Rom!)
Mitsumi FX-300 (3x speed)
Mitsumi FX 400 (4x speed)
Chinon CDS-545 (4x speed) <-- very good drive!!!!!
Wearnes CDD-220A (4x speed)
Sony CDU-55E (2x speed) <-- Audio play requires CacheCDFS 2.5 or better
NOTE: The CD32-Emulator will only work with the Sony CDU-55E, if no volume
control is enabled in the emulator's preference window.
Acer 6825-P (2x speed)
Wearnes CDD-120A (2x speed)
Chinon CDS-525I (2x speed)
The following drive cannot play Audio with Amiga CDDA Audio players,
but data read operation is ok. The CD32-Emulator will not work correctly
due to the problems with CDDA-Audio.
Unfortunately the SCSI-II Inquire command does not work with this drive,
if no CD is inserted.
Even if it may be used to read data, I can not really recommend this
drive:
Elitegroup Vertos 300SSD (2x speed)
These drives use a bit more CPU as they have problems with the
implementation of interrupts with the Amiga IDE port, but they work
quite well (Audio & Data) and can still be recommended:
NONE (All drives use interrupts with Release 5.9)
TESTED FILESYSTEMS
The device has been tested with the CacheCDFS (yes, this is written
by me, too) and my PlayCD Audio player.
It works very well with my CD32-Emulator.
However, I don't expect any problems with other filesystems.
INSTALLATION
Installation is simple.
Connect an IDE-ATAPI drive to your IDE port.
You should jumper the drive as a SLAVE device, even if you do
not have an IDE harddrive connected, as the A4000 may not boot
if it encounters an ATAPI CD-Rom as the Master device.
However, IF your Amiga does boot with a CD-Rom as the master
device, you could use two CD-Roms at the same time.
The unit numbers will be 0 (for the master) and 1 (for the slave).
If you have an IDE harddrive, you should buy a standard PC-IDE
harddisk cable, as the original A4000 cable is too short for both an
IDE harddisk and a CD-Rom drive.
The harddisk should be jumpered as the Master device and the
CD-Rom as the slave, otherwise the Amiga will not recognize
the harddrive.
Copy the a4000_atapi.device to your devs: directory.
The supplied installer script will do this for you.
Now you must tell your CD-Rom FileSystem about the device.
This differs from product to product, please consult the manual
of the Filesystem you wish to use.
With CacheCDFS, simply run the CacheCDFS installation program.
It will automatically detect your CD-Rom.
A CD-Rom connected as the slave device will have unit number 1, which
will be the common case.
A CD-Rom connected as the master device will have unit number 0.
The name of the device driver is a4000_atapi.device.
KNOWN PROBLEMS
It is possible, that some drive models cannot be mounted after a reboot,
because they need some time to wake up after a hardware reset.
(On a PC it takes often a long time until the CD-Rom is accessed)
This depends on how "fast" your startup-sequence reaches the mount
command.
If you have this problem, add a delay (e.g. Wait 3) before the mount
command in your startup-sequence.
That's it!
Please send comments, bug reports, etc to:
Elaborate Bytes
Oliver Kastl
Am Westpark 5
81373 Munich
Germany
Compuserve: 100447,3361
Internet: 100447.3361@compuserve.com
To order the CacheCDFS, the CD32 Emulator, the a4000_atapi.device
or all of the above, please contact:
Hirsch & Wolf OHG
Mittelstr. 33
56564 Neuwied
Germany
Tel.: ++49-2631-83990
Fax.: ++49-2631-839931
or
NBG-USA, Inc.
482 Holly Ave.
St. Paul MN55102
USA
Tel.: ++1-612-2909447
Fax.: ++1-612-2909449