There are five types of CD-ROM drive, each connecting with a different 
interface (the interface is what controls the flow of data as well as 
electrical signals going to and from the drive).  Having a CD-ROM drive 
hooked up to the wrong interface is bad (very, very bad).  It insures that 
your drive will not work, and may actually damage it as well. 

The most common interfaces are: 
IDE - 40 pins
SCSI (pronounced "scuzzy") - 50 pins

Other types of CD-ROM drive interfaces are: 
Sony - 34 pins
Mitsumi - 40 pins
Panasonic / Creative - 40 pins

These types do NOT indicate who makes the drive - they simply indicate the 
interface format being used.  Mitsumi used to make 2x drives using the 
Mitsumi interface, but now make drives using the IDE interface.  Virtually 
ALL drives being manufactured today are either IDE or SCSI (the exception 
is the Teac CD55-A which uses the Panasonic interface).  

If you purchased a 4x, 6x, or 8x drive from Turtle Beach, then it is an 
IDE drive.  Turtle Beach only has two SCSI drives - the TBS7400 (which is 
a 7-disc changer) and the TBS2040/2050 (which is a recordable CD drive).  

The guidelines in this tech sheet will cover IDE. 

What Is IDE? 
------------
IDE stands for "Integrated Device Electronics" (or "Integrated Drive 
Electronics", depending who you ask).  It is also referred to as ATAPI and 
it is a standard in today's IBM-compatable computer industry.  All the 
CD-ROM drives that Turtle Beach sells are ATAPI 1.2-compliant, which is a 
necessity for using the drive in OS/2 or Windows NT operating systems. 

Different types of IDE devices exist.  In addition to CD-ROM drives, there 
are IDE hard drives, and the SyQuest EZ-Drive 135 (which is a cross between 
a floppy drive and a hard drive).  The IDE specification ensures that all 
ATAPI 1.2-compliant devices will operate in similar fashion. 

The industry has set up defaults for the IDE interface.  Up to four can be 
installed in the system, they are called primary, secondary, tertiary and 
quaternary.  Additionally, two IDE devices can be installed on each 
interface, which means up to eight IDE devices can operate simultaneously 
in the system (two on each of the four interfaces). 

To install two devices on one interface (using one cable) one must be set 
up as a "master", and the other as a "slave".  This allows them to coexist 
using one set of pins.  If both were set up as "master", they would 
continuously fight over who was going to be in charge and nothing would 
work. 

For compatibility reasons, the IDE ports have the following default 
settings: 

INTERFACE              PORT      IRQ
primary                1F0       14
secondary              170       15
tertiary               1E8       12
quaternary             168       10

IRQs, also referred to as "interrupt requests", are channels through which 
devices communicate with the CPU.  If two devices use the same IRQ, they 
will not function correctly.  The computer might lock up or reboot itself 
at odd times.  

The IDE ports' default settings normally cannot be modified, which can be a 
problem on some systems.  There are four defaults for the IDE interfaces. 
Most Pentium computers include two built on to the motherboard.  These would
be the primary and secondary ports, and they are hardwired at port 1F0 / IRQ
14 and port 170 / IRQ 15, respectively.  THESE SETTINGS CANNOT BE CHANGED. 

Turtle Beach CD-ROM drive interface cards and Turtle Beach sound card IDE 
interfaces default to the secondary port.  If system includes both a built-
in secondary IDE interface and Turtle Beach interface card (set up for the 
secondary port), neither one will work because they will be in conflict.  
If the secondary port is built in to the motherboard (or on another card),
it should be used instead of the Turtle Beach interface card.  Plugging an 
IDE CD-ROM drive in to the secondary port of the motherboard is preferable 
to using a seperate card, as it interacts directly with the CPU and may 
provide slightly better performance. 

To tell if a secondary port is built in to the computer: 

1) Consult the computer or motherboard manual. 
2) Inside the computer, locate the hard drive, and note where the data 
   cable (the large grey flat ribbon cable) leads.  Check for a second 
   connector (a second set of 40 pins, in two rows of 20) near where it 
   is connected. 

If no second connector is present, use the IDE port on the Turtle Beach 
Sound Card.  The only conflict possible is if another device in the system 
uses the settings of the IDE interface.  Some SCSI cards and network cards 
may have the ability to use these settings, which will cause a conflict. 
Changing the settings so the card uses different resources should fix this 
problem. 

Note to IBM PS/1 owners: 

The majority of IBM PS/1 computers have motherboards that use IRQ 15 for 
some motherboard function.  What this means is that a secondary IDE card 
will not work in the system.  (Not all of the IBM computers will experience 
this situation.  If you do have a PS/1, contact IBM and inquire as to the 
possibility of installing an IDE CD-ROM drive into your particular system.)

Note to 486 SX owners: 

Many early 486 SX computers will not allow an IDE CD-ROM drive in the 
system.  The drivers may load, but the machine will experience strange 
slow downs, or a wide variety of errors and General Protection Faults in 
Windows.  This is most evident on certain Packard Bell machines, though 
any SX motherboard could be affected.

Connecting a CD-ROM to the hard drive: 

The possiblility of this working depends on the IDE interface card being 
used.  Many of the older (pre-1995) IDE cards will be horribly confused by 
a CD-ROM drive attached to them.  Unless absolutely necessary, it is not 
recommended to slave a CD-ROM drive off a hard drive - it may not work, and 
it may affect system performance.  

In the case of IDE ports with Ultra DMA support, you cannot use the CD-ROM
on the same IDE channel as the hard drive.  Other options are available, 
including installing an external card with tertiary and quaternary (third 
and fourth) ports.  Such a card can be purchased at a computer store or 
through mail order.  Both DTC and Promise Technology manufacture such cards. 

Note to Sound Blaster owners: 

The Sound Blaster 16, 32, and AWE32 sound cards utilize either the tertiary
or quaternary ports for their built-in IDE interface.  However, the 
manufacturer (Creative Labs) has chosen a non-standard tertiary port for 
their cards.  It is possible to change the IRQ of the tertiary port (it can 
be either 12 or 11) and the quaternary port (it can be either 10 or 9).  
The default setting for the tertiary port is 12, but Creative Labs uses 11, 
which can pose some problems if the CD-ROM driver needs to have specific 
command line parameters.  (For further assistance, contact Creative Labs.)