CD Changers and OS/2 Warp

By Fernando Cassia

About this FAQ
This document is an attempt to minimize problems for current owners and also potential buyers CD-changers (multi-disc cd-rom readers) that plan to use them with OS/2 Warp.

All the initial information comes from my personal experience with the Nakamichi MBR-7 (7-cds, 4-x) working on OS/2 Warp 4.0. If you have other cd-changer running under os/2 please send me your experiences with it.

- Thanks in advance, Fernando.

Q: Does the Nakamichi MBR-7 changer work with OS/2?
A: Yes!. Not only the MBR-7 but *ANY* SCSI cd-changer should work with OS/2 Warp too. Many ATAPI (IDE) CD-Changers are known to work too!.

Q: Where are the OS/2 Drivers for my SCSI CD-Changer?
A: There are no drivers needed!!, you only need an OS/2-supported SCSI card. The SCSI drivers for your your controller and OS/2 Warp's OS2CDROM.DMD will do the rest. The unit is automatically detected and additional cd-rom objects for each disc in the drive show up in OS/2's "Drives Folder".

Q: Why does OS/2 show it as only ONE cd, and not the total number of discs?
A: SCSI cd-rom changers have a single SCSI ID#, but configure each cd disc in the drive as a separate cd-rom unit, each using a different scsi logical unit number (LUN). By default, most OS/2 scsi drivers do not scan for additional LUNs on each SCSI device. However, LUN detection can be easily turned ON on most scsi drivers.

Q: So, how do I enable additional LUN detection in my SCSI card's OS/2 driver?
A: If you have an Adaptec, Future Domain, IBM or DPT scsi controller:

Add the /ET switch to your SCSI driver loading line in CONFIG.SYS to enable SCSI device searching for logical units (LUNs).


 * Examples:


 * Adaptec: BASEDEV=AHA154x.ADD /ET /V
 * Future Domain:BASEDEV=FD8XX.ADD /ET /V
 * QLogic: BASEDEV=QL10OS2.ADD /ET /V

If you have an AdvanSys scsi controller:

Add the /L switch to enable LUN detection.

BASEDEV=ASC.ADD /L /V
 * Example:

If you have a BusLogic scsi controller:

Add the /LUNS:nn switch. This switch specifies the maximum number of logical units the host adapter will support or try to detect. The valid range is from 1 to 64, but a value of 7 will be enough for most cd changers.

BASEDEV=BTSCSI.ADD /A:0 /LUNS:7
 * Example:

Q: Can I connect a SCSI CD-Changer to a HP CD-Writer and its bundled SCSI controller?
A: Yes. This is the setup I am running, and it works OK. Use the Advansys parameter mentioned above to use a SCSI cd-changer connected to the HP SureStore 4020i's bundled controller.

Q: What about CD Changers with IDE interface?
A: This comes from Clark Tompsett (ctompset@7cities.net), and applies to the Panasonic IDE (Atapi) changers. It SHOULD WORK on all other IDE CD changers, so please let me know.

You can use the Panasonic 5 x 10 cdrom changer under OS/2 provided you make the following changes to your config.sys. You must modify the ibm1s506.add driver or OS/2 will not see the drive. Set you ibm1s506 to the following:

BASEDEV=IBM1S506.ADD /a:1 /u:1 /atapi


 * where /a:x is the adapter
 * where /u:x is the unit (0 for master, 1 for slave)
 * the /atapi is required.

You will hear the system cycle the 5 trays and you will have 4 more cdroms and cd audio icons. Tested with Warp 4.

Q: I am getting really TIRED of the constant TRAY CYCLING on my cd-changer while using OS/2 for other tasks that do not access the CD-Changer. What is the cause?
A: OS/2 device driver guru Sam Detweiler reported that the problem is the WPS testing all reported drives a lot. X-File does the same thing for its buttons if you are using a version older than 1.2. One quick and dirty workaround, (but not elegant at all) is leaving a slot empty and opening that slot. Of course you have to close it to USE the drive : - ).

Q: Is there a solution to eliminate the ANNOYING HABIT of the OS/2 WPS (Workplace Shell) of scanning all drive letters before doing something useful (or not useful :)?
A: YES!, Jens Glathe of Germany has modified the OS/2 CD-ROM device manager (OS2CDROM.DMD) to prevent fast subsequent requests to different slots of a changer. After testing it succesfully for over 6 months with both Warp 3 and Warp 4, he decided to make his code public and asked me to include it into this FAQ.

His program works perfectly here, and makes life a little easier for OS/2 CD-Changer owners.

Download the following file and say goodbye to the annoying tray switching!:


 * CDROMMGR.ZIP (53,060 bytes, released June 18, UPDATED July 7)


 * CDRMUPD3.ZIP (15,442 bytes, released July 9)

Q: I use a CD-Writer with Unite CD Maker for OS/2 so I need to use CTCDROM.DMD instead of the normal OS/2 CD-ROM manager. What can I do??
A: Jens Glathe is going to develop this same support but in the form of a .FLT "filter" so you can achieve the same function no matter what cd-rom manager (CTCDROM.DMD, OS2CDROM.DMD or any other) you use. Feel free to E-Mail him if you want to see this developed.

History

 * V1.3	UPDATE of Jens Glathe's CDCHANGER DEVICE MANAGER for improved cd-changer support wihout annoying disc access and tray switching while doing common WPS operations. (98-7-9)
 * V1.2	Jens Glathe's PATCHED DEVICE MANAGER for improved cd-changer support wihout annoying disc access and tray switching while doing common WPS operations. (98-6-26)
 * V1.01	Minor maintenance (98-1-2)
 * V1.0	Original Version (97-1-1)