How to Install a CD-ROM Drive
Last updated: 6/7/02

INTRODUCTION.  The purpose of this article is to show you how to install and configure a CD-ROM drive.  How configuration choices affect performance will also be discussed.  For this article we are going to use the AOpen 948E 48X, UDMA 33 CD-ROM drive as our primary example to establish a context for these instructions.  The information and principles provided are applicable to most ATAPI/UDMA (Advanced AT Packet Interface/ Ultra Direct Memory Access--AT refers to Advanced Technology from the days of the IBM AT computer) CD-ROM drives on the market.  Furthermore, with exception of installing application and decoder software/hardware, these procedures should be useful in understanding how to install many DVD drives.

HOMEWORK.  First, one should visit the manufacture's web site and review the CD-ROM FAQs, etc. and download the latest drivers for the drive.  For example, the diagram in the 948E User's Manual of the rear of the drive is not correct.  The one to the right came from AOpen's web site and matches the drive.

UDMA?  There is a jumper (arrow) on the rear of the 948E to disable or enable UDMA 33 (33 Mhz) operation.  It comes jumpered with UDMA disabled.  The EpoX MVP3G2 motherboard in my test computer detects the drive as PIO Mode 4 with the jumper in place and UDMA 33 with it removed.   You would remove the jumper for most recent motherboards and Windows 98.  You would leave the jumper in place for motherboards which don't support UDMA 33 and Windows 95.  The stock Windows 95 UDMA driver is not designed for CD-ROM drives and Windows may lock-up if used with the 948E set for UDMA 33.  Your motherboard/CD-ROM drive may have come with a UDMA 33 driver for Windows 95 which will work with the drive.  See the readme.txt file on the 948E floppy (and similar files on the floppy which came with your particular CD-ROM drive) and AOpen's CD-ROM FAQs.  My benchmarks  show that the 948E  transfers 104 MBytes to a hard disk in 36 seconds in PIO Mode 4 and does it in 34 seconds in the UDMA 33 Mode--not much difference.  Many CD-ROM drives do not have this jumper, and others have manufacturer/model-specific jumpers which should be reviewed.

MASTER, SLAVE, C/S AND IDE INTERFACE.  The 948E may be jumpered as Master, Slave, or for Chip Select.  The jumper positions are labeled on the back of most drives.  I usually jumper a CD-ROM drive as master and connect it to the Secondary IDE interface on the motherboard.  You would jumper it as a Slave if a faster drive is also connected on the same cable to the Secondary IDE Interface (however, it is usually left as a Master if a Zip drive is on the same cable).  If you are consistent from installation to installation, you will know how a drive is normally jumpered without poking around with a flashlight months after a drive is physically installed.  On my test computer, the 948E moves 104 MBytes in 34 seconds jumpered as a Master and moves the same data in 36 seconds jumpered as a Slave, with no other drives on the Secondary IDE interface.  I have yet to jumper a CD-ROM as chip select, but some motherboards/computers may require it.  UDMA 66 drives use chip select.  If you connect the CD-ROM as a Slave to the same cable as your primary hard disk jumpered as a Master with a slave present), which is certainly possible, but a last resort, it may slow-down your hard disk and will slow down CD-ROM to hard disk transfers very noticeably.  Benchmarks with the 948E show that it takes about seven times longer to move 104 MBytes of data from a CD-ROM on the Primary IDE interface to a hard disk on the same interface as it does to transfer the data from a 948E on the Secondary IDE Interface to a hard disk on the Primary IDE Interface.

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