This document discusses the various configuration options for the NeXTSTEP 3.3 EIDE driver, version 3.31.

Overview

The EIDE driver version 3.31 for NeXTSTEP 3.3 supports ATA-1 and ATA-2
(X3T10 documents 791D and 984D respectively) conformant IDE hard disks and
ATAPI compliant (SFF 8020 revision1.2) CD-ROMs.

The EIDE/ATAPI driver can be used in various modes (or personalities). These
are the options available while installing NeXTSTEP or in Configure's Add
Devices Panel.

1. EIDE and ATAPI Device
- full EIDE/ATAPI support
2. EIDE and ATAPI Device Controller for PC Tech RZ1000 PCI
- same as above but is optimized for RZ1000 PCI interface
3. Intel GX/Professional IDE Disk Controller
- only for Intel GX/Professional machines. Supports host-master DMA on
these systems.
4. IDE Disk Controller
- provided for compatibility reasons

The EIDE/ATAPI drivers (1 and 2 in the list above) get the disk geometry
from the drive itself. The IDE Disk drivers (3 and 4 in the list above) get
the geometry from the BIOS instead. If you are installing NeXTSTEP you should
always use the EIDE/ATAPI device drivers.

Features of the driver

+ Supports PIO mode 0 to mode 4 hard disks
+ Disks of size up to 8.4GB is supported by the driver
+ Primary and secondary controllers can be used
+ Supports up to two devices on each controller
+ Support for Logical Block Access (LBA) mode
+ Support for PCI IDE (32-bit data access, faster transfers)
+ Support for ATAPI CD-ROMs.

Configuring Hardware

The primary controller should be configured for port address 0x1f0-0x1f7 and
irq 14. The secondary controller should use port address 0x170-0x177 and irq
15. You must enable primary and secondary (if applicable) controllers in
your system BIOS.


IDE/EIDE Disks

ATA-1 and ATA-2 disks are supported by the driver. The driver uses the disk
at maximum possible data rate. The IDE controller must support IOCHRDY (IO
Channel Ready) line for a disk to be be used in Mode 3 or Mode 4. If your
controller supports this line you should enable it in Configure. The driver
uses the disks in multiple sector mode for better performance but you can
disable this in Configure if desired. The EIDE/ATAPI drivers use LBA mode for
disk access if the disk supports it.


ATAPI CD-ROM

ATAPI devices appear to the system as SCSI devices. Hence it is possible to
install NeXTSTEP using an ATAPI CD-ROM and use it with other applications
like CDPlayer.

If you are installing NeXTSTEP using an ATAPI CD-ROM you must connect the
IDE hard disk and CD-ROM to the primary controller. The hard disk should be
configured as master or as master with slave present (if this option is
available). The ATAPI CD-ROM should be configured as slave. This is usually
accomplished by changing a jumper on the device. After this you can proceed with
NeXTSTEP installation in the usual way.

When prompted to select the SCSI adapter connected to your CD-ROM drive,
select the Adaptec 154x SCSI driver to continue. When prompted for the type
of disk controller the hard drive is connected to, select the EIDE and ATAPI
driver. Once NeXTSTEP is installed you should remove the Adaptec154x driver
with Configure.app. Requiring a SCSI driver to be loaded is a bug and will
be fixed in a later version of NeXTSTEP.


Upgrading from an older IDE driver

The version of the IDE driver that shipped with NeXTSTEP 3.3 is version
3.30. The new EIDE driver is version 3.31.

1. If you are currently using the "IDE Disk Driver " you should upgrade to
"IDE Disk Driver ".
2. If you are using the "IDE Disk Controller for large disks (> 504MB)" you
should upgrade to EIDE/ATAPI driver.
3. If you are running with the special driver designed for Intel
GX/Professional, you should use the new driver of the same name.


Bugs and Warnings

1. Disk drives and ATAPI CD-ROMs attached to the secondary controller are
not available while installing NeXTSTEP due to system software limitations.
However once NeXTSTEP is installed the secondary controller can be
configured. You can do this by running Configure and adding the same driver
again (set port address to 0x170-0x177 and irq to 15).

2. Due to a bug in Configure, primary and secondary ports must have the same
personality of the driver. For example, you can not use IDE driver for the
primary controller and EIDE driver for the secondary controller.

3. It is very important that the system BIOS recognize and be able to use
all of the disk. Some BIOS's automatically do this when you power up the
machine but for some you will have to do it yourself. Make sure that BIOS
reports the actual disk size correctly (though the number of cylinders and
heads may be different).

4. Some old BIOS's do not work with disks larger than 504 MB (1MB = 1 048
576 bytes). You can still use such disks with NeXTSTEP but not as a boot
disk. A workaround is to connect this as a slave to a boot disk or on the
secondary controller (if available). Or you can update your system BIOS.

5. You should attach ATAPI CD-ROMs to the secondary controller in your
system (if available) for better performance.

6. ATAPI is an emerging standard and there are many incompatibilities in
implementations. We recommend that you use ATAPI CD-ROMs as single master
on a controller or as slave to an IDE disk. Many on-board PCI/VL-bus
interfaces do not work very well with ATAPI CD-ROMs.

7. You should not switch between IDE drivers (3 and 4 in the list under
heading Overview) and EIDE drivers. Since they get their drive geometries
differently you may corrupt the data on your disk.

8. Different BIOS's implement LBA decoding differently. If you have DOS
partition on an IDE disk and move it to a different system which also
supports LBA your disk might become unreadable or corrupt.

9. NeXTSTEP does not use BIOS for disk access except for booting. Therefore
the BIOS must see the disk of the same size as the driver. In other words, if
you are using a disk larger than 504 MB you must ensure that the BIOS
recognizes all of the disk. You may need to enable "geometry translation" or
its equivalent in the BIOS to do this.

10. Caching IDE controllers and add-on IDE controllers with BIOS on them are
not supported.

11. Mode sense/select commands do not work for ATAPI devices.