Installing IDE Devices

This document will guide you through the procedures for the installation and







use of IDE devices, including hard drives and CD-ROMs.

Installing IDE/EIDE Hard Drives

I. Check to make sure that your system has the proper hardware and support for your ide devices. A. Check for an IDE controller. This is either a card that fills a slot, or more commonly these days, it is integrated into the motherboard itself. In either event, the controller must be present. 1. Your controller will have one or two channels. Each channel will support two devices. If you wish to use the second channel, you must make sure your motherboard supports it in the CMOS. 2. If in your STANDARD CMOS SETUP you have only two lines for hard drives (or possibly one line), you will not be able to use the second channel for a hard drive, even if the controller card does support it. B. Check to ensure that your motherboard supports LBA (Logical Block Addressing) Mode. 1. Without LBA Mode support, you will need a software driver to access any capacity over 528MB. Some "Smart Card" controllers have a built-in BIOS for LBA mode. An example is the Promise 2300+ Vesa Local Bus controller. You may use this card to access the full capacity of the drive if your motherboard does not support LBA mode. 2. If you are not able to find a card or motherboard that supports LBA mode, you can still use a software driver to maximize your space. These drivers generally are adequate, but they take up memory and run a bit slower than full hardware support does. OnTrack software makes the most common EIDE driver, called Disk Manager. See their contact information at the end of this document. C. Ensure that your IDE cable has three connectors on it. 1. One connector plugs into the controller, leaving two connectors for devices. It makes no difference which connector you use to attach your IDE device; either will work. 2. If you are using two device on a single channel, one must be designated master and the other designated slave. a. These settings are almost always changed by jumpers or switches on the devices themselves, and not on the controller. If you are using two hard drives, one must be a master and the other a slave. b. Hard drives usually have jumpers on them to set the mode as either master or slave. You will boot off of the master drive, but after booting you will be able to access the storage on both the master and slave. II. Mount the drive in the case. A. You should use 1/8" screws. These will come with the hard drive or with the case. If you use screws that are too long, you will damage your drive. B. Insert the drive with the IDE socket exposed to the inside of the case. C. Line up the screw sockets on the sides of the drives with the gaps in the subchassis of the case. D. Secure the drive with two screws per side. III. Install the power and IDE cables. A. The power connector is keyed, so it will not go in unless it is aligned properly. The IDE cable, however, can go either way. If it is put on backwards, your drive will not work. **Make sure that the braided red side of the cable is installed on pin 1 on both the controller and the drive. Both should be indicated.** IV. Setup your drive in the CMOS. Assuming you have a motherboard that does auto-detect and support LBA mode, all you need to do is set up your CMOS values and run the utility. A. Power up the system and enter the CMOS. This is usually accomplished by pressing the DEL key during boot-up. B. Initialize your hard drive by autodetecting it. If you have a newer motherboard, you should have an auto-detect feature. 1. Select the autodetect feature. If your CMOS does not have an Autodetect feature, you will need to enter the parameters manually. 2. Choose the setting that features the appropriate mode. a.LARGE: This is very similar to normal mode, but you can exceed 1024 cylinders. This is faster than LBA mode, but it will not always format to the full capacity. You may also run into compatibility problems. This is a good way to set your drive if you have only one operating system. You may expect to see better performance with large than with LBA, but it is not as versatile. b.LBA: Logical Block Addressing, as mentioned earlier. This mode allows you full access of all the space on the hard drive. It is also very stable. We usually set up LBA Mode as the default, since it is a bit more reliable than Large Mode. c.NORMAL: For use with older or pre-existing hard drives that have already been formatted, or drives that do not exceed 1024 cylinders. This is the old standard that works just fine, but does not add any of the newer features. d. Save your changes and exit. After you select a mode, the utility will automatically update your standard CMOS section. C. Setup your remaining EIDE values. 1. In the CMOS, you should have BIOS FEATURES and CHIPSET sections. Go to these sections. 2. Depending on the motherboard, the following values should be present in one or the other of those sections. Here is a checklist of values to set (if available):
LBA Mode: Enabled
32-bit Access: Enabled
HDD Block: Enabled
IDE Second Channel: Enabled (only if you need it)
IDE Timing: Try the fastest first; adjust if needed
These values should be explained in detail in your motherboard manual. V. Now, install you OS using a system boot disk. The following are directions for MS-DOS A. Insert the disk labeled DISK 1 into the floppy drive. 1. The system will boot off the floppy and bring you to an installation screen. 2. If you plan on using just DOS on only one partition (which most people will do), just hit Enter and DOS will allocate your partition automatically. 3. Just follow the directions on the screen and you will install the software without any problems. If you wish to install multiple operating systems or partitons, you will need to run an FDISK program. Each operating system has its own variation, but they all seem to be fairly straight-forward and well documented.

An important note about MS-DOS partitions

DOS has a pre-configured file allocation unit depending on the size of the partition. A small partition will have an allocation unit of 1024 bytes, or 1K. That means the smallest "chunk" of usable space is 1K. A file that was 256 bytes would still take up 1024 bytes of hard drive space, since that is the smallest allocation unit available, just as a file that was 1200 bytes would take up 2048 bytes of hard disk space. This is a feature of the FAT (File Allocation Table) that is unavoidable. The problem arises when large partitions are created.

DOS Partitions over 1GB have an allocation size of 32K! That means the 256 byte file mentioned above would actually take up 32,768 bytes of hard disk space! A 32K allocation unit will eat up you hard drive very quickly. We have transferred the contents if a 250MB hard drive onto a 1.2GB hard drive, and the files that took up about 240MB before took up over 400MB after! The way to avoid this problem is to split up your DOS partitions into chunks no larger than 850MB or so. Most other operating systems (Linux for example) allow you to define what your allocation unit is. You do not want it too small (or else your performance will suffer), and you do not want it too big (for above mentioned reasons). If possible, set your alloaction size to 2048 or 4096 bytes.


Installing an IDE CD-ROM

Installing an IDE CD-ROM is similar to installing a hard drive. You still need to consult a jumper on the CD-ROM to set the device as a master or slave, you need to mount it with short screws, and attach the power and IDE cables properly. You do not need to define any parameters in CMOS. Your only decision becomes whether to use the first or second channel.

The first channel is nice because it is easy to set up. Simply set the jumper to slave, and connect thr CD-ROM to the same IDE cable used by the hard drive. The CD-ROM sotware should set up your drivers automatically, and you will have nothing else to worry about. If you chose this, disable the second IDE channel.

The disadvantage of using the first channel for both is the fact that a CD-ROM is only 16-bit, and it will force the whole channel to act in 16-bit mode. Even if you have a 32-bit hard drive, you will not be able to access it in 32-bit mode if it is sharing with a 16-bit device. To not hinder the hard drive, it is best to put the CD-ROM on its own channel. Set the jumper to master, install it on the second channel, and run the software as before.

If your motherboard only supports one channel, you should be able to provide a second channel for a CD-ROM though an ISA IDE controller, such as the one built into an IDE sound card. This may be a bit-tricky, and you will need to consult the harware manuals to configure things properly.