Hardware Reference
In-Depth Information
all Windows NT, 2000, and newer discs are directly bootable on those systems, thus greatly
easing installation.
I normally recommend keeping ATA devices you are accessing simultaneously on separ-
ate channels. Because ATAdoesnottypically supportoverlapping access, whenonedrive
is being accessed on a given channel, the other drive on the same channel can't be ac-
cessed. By keeping the CD-ROM and hard disk on separate channels, you can more ef-
fectively overlap accessing between them. Another caveat is that a PATA device such as
a hard drive might be incapable of functioning if another Parallel ATAPI device (CD or
DVD drive) is master. Therefore, in most cases, you should try to set PATA hard drives as
master (device 0) and Parallel ATAPI drives as slave (device 1) on a given cable.
ATA Drive Capacity Limitations
ATA interface versions up through ATA-5 suffered from a drive capacity limitation of
about 137GB (billion bytes). Depending on the BIOS used, you can further reduce this
limitation to 8.4GB, or even as low as 528MB (million bytes). This is due to limitations
inboththeBIOSandtheATAinterface,whichwhencombinedcreateevenfurtherlimita-
tions. Tounderstand these limits, youhave to look at the BIOS (software) and ATA(hard-
ware) interfaces together.
Note
In addition to the BIOS/ATA limitations discussed in this section, various operating system
limitations exist. These are described later in this chapter.
The limitations when dealing with ATA drives are those of the ATA interface as well as
the BIOS interface used to talk to the drive. A summary of the limitations is shown in
Table 7.12 ATA/IDE Capacity Limitations for Various Sector Addressing Methods
