OS/2 Warp Compatible Hardware List Web site: The Complete OS/2 USB Story
USB and OS/2 (Part 1: Basic USB support: controllers)
Jonas Buys, 2003/06/07F, 2004/06/01M
OS/2 and hardware... For more than a decade, OS/2 has been misjudged to have
very limited hardware support. But in fact, if you dig some further, you'll
notice that OS/2 Warp and eComStation offer extreme large and powerful hardware
support. Recently, a whole lot has changed ever since USB support became available
for OS/2. Over the last two or three years, IBM has provided us with some great
device drivers, which enable the use of several hundreds of older and modern
USB devices with the OS/2 Warp family of operating systems. The upcoming series
of articles will discuss all IBM USB drivers thoroughly, and list a lot more
OS/2 compatible devices and chipsets than the very limited number IBM tested
with the drivers.
This article was intended both for novice and advanced OS/2 users. Also, this
article should be considered to be an introduction offering basic knowledge
for the upcoming articles.
- USB Inner Workings
- USB Design
- Wiring details
- USB Topology
- PC - USB Device Communication
- USB: the bad, the ugly, the beauty
- Some common USB Terminology...
- Base USB Device Driver Installation
- Regular IBM OS/2 Warp
- eComStation 1.1
- USB Device Driver options
- What you should think of when choosing a USB controller
- OS/2 CHL Tested USB Controllers
- And what about Linux?
USB (Universal Serial Bus) is a plug-and-play interface between a computer
and a whole variety of add-on devices, such as keyboards, mice, Ethernet cards,
scanners, printers, et cetera. With USB, a new device can be added to your computer
without having to add an adapter card or even having to turn the computer off.
The USB peripheral bus standard was originally developed by Compaq, IBM, DEC,
Intel, Microsoft, NEC and Northern Telecom and the technology is available for
all computer and device vendors.
Today, a PC user expects to be able to connect a wide range of external devices
to his or her system; not just printers and modems, but scanners, cameras, mass
storage devices, PDAs and a very diverse set of other peripherals. But for a
long time, anyone attempting to do so was hampered by a lack of suitable input/output
ports. Before USB were even invented, the only universal interface for the PC
had been SCSI, an expensive and superb option only justified for high-bandwidth
devices, especially suited for server needs. Lower speed peripherals generally
required either a serial or a parallel port, or used a proprietary interface.
Designed originally for printers and low speed modems, the PC's serial and parallel
ports leave a lot to be desired as general purpose interfaces. Their data transfer
rate is awfully low (maximum 115Kbps for the COM port, up to 400KBps for an
LPT port) and each device requires its own hardware interrupt (IRQ) which limited
the amount of expansion possible. Plug-and-play? Never heard of that with those
The need for a medium-speed, inexpensive plug-and-play interface that could
be used to branch a virtually unlimited number of devices was eventually recognized,
and the solution would be the Universal Serial Bus.
1.1. USB inner workings
1.1.1. USB Design*
The USB was designed to allow large numbers (up to 127) of low- and medium-speed
peripherals to be attached to a PC. With an initial maximum transfer rate of
12Mbps, USB was never intended to be an alternative to SCSI. Even today, Hi-Speed
USB still can't compete with the newest SCSI standards. Nevertheless, the technology
is still much faster than the serial or parallel ports.
USB was designed to be plug-and-play. Devices can be added and removed even
while the system is running, avoiding the need to reboot the system to reconfigure
it. Technical issues like bus termination and the assignment of device identifiers
are taken care of by the hardware and software architecture so these common
sources of configuration error will not be a problem. Concerns for power conservation
have been catered for by allowing devices to be suspended and resumed.
Typical USB devices are those requiring low and medium bandwidths. At the bottom
end of the bandwidth range, USB could be used to connect a keyboard and mouse
to a PC. At the top end, scanners, backup devices or cameras for video-conferencing
applications could use USB, eliminating the need for proprietary interface boards
with their associated installation and configuration problems.
The bus architecture, in which data for different devices travels across the
same cable, also has the potential for simplifying connection requirements.
For example, a mouse could plug into a keyboard, and a single cable would then
link these with the PC.
1.1.2. Wiring details...*
USB devices are connected together using an inexpensive white or black jacketed
four-wire cable with a characteristic impedance of 90 ohms. USB devices can
be either self-powered (with their own independent power supply) or bus powered.
One of the pair of wires in the USB cable is used to carry a 5V power: pin 1
carries the supply voltage of +5V, pin 4 is the ground. There are two classes
of bus-powered devices. Low power devices may draw no more than 100mA of current,
whilst high power devices can draw up to 500mA once configured.
The second pair of wires, D+ and D- on pins two and three, is a twisted pair
used to carry data. A high voltage on D+ but not on D- is a 1 bit. A high voltage
on D- but not on D+ is a 0 bit.
The USB operates at two distinct speeds. Full speed gives a bandwidth of 12Mbps.
At this speed, shielded cables must be used to obtain adequate noise immunity
and prevent electromagnetic interference (EMI). Shielded cables are about 5
mm in diameter, and cable segments can have a maximum length of 5 meters.
For applications that require a low bandwidth a lower speed operating mode is
available. This allows slightly thinner, cheaper unshielded cable to be used.
Cable length is reduced for the unshielded cable to a maximum 3 meters. To prevent
the high speed signal being transmitted over unshielded cable (which would cause
EMI) and to avoid the risk of low speed devices misinterpreting full speed data
as commands to which they should respond, communication with low speed devices
is disabled whilst full speed signaling is being used.
Two types of plugs and sockets, known as series A and series B, are specified
for USB. Series A plugs and sockets are for use with devices to which the external
cable is permanently attached, for example keyboards, mice and hubs. Series
B connectors are used when the USB cabling is detachable, as in the case of
printers, scanners and modems. The two types are not interchangeable.
The series B connectors are about 11 mm x 12 mm with the contacts recessed.
The mating plug provides a fully shielded connection.
1.1.3. USB Topology*
USB uses a multi-level star topology which looks like a tree. Places where
the bus divides into two or more branches, a hub is present. At the end of each
branch is a peripheral function. The word function in this context is a specific
Each physical USB device consists of a bus interface, a logical device and one
or more functions. The bus interface is standard for all USB devices. The logical
device is the user view of the device. In physical terms it might contain a
single function, or it could consist of several functions with an embedded hub.
An example of a multi-function device with embedded hub is a keyboard with built-in
Hubs have ports or attachment points that allow other USB devices to be connected
to them. Each length of cable starts at a hub and ends at another device. Each
connector is terminated, so cable termination is automatic and not something
users will need to worry about. At the host there is just a single hub, known
as the root hub, attached internally to one or more USB ports. There can be
only one root hub per USB interface.
In PC hardware terms the root hub, or rather the USB controller through which
the PC software controls it, is a single device with its own IRQ and I/O requirements.
Once set up, the USB will not require any hardware reconfiguration no matter
what devices you plug in to it. All you will need to do is install the driver
software for the new device.
The USB technology is designed to allow "dynamic" attachment and removal
of devices, while the system is running (the so-called hot-plugging). This is
achieved using an ongoing process of bus enumeration, which constantly checks
what devices are on the bus.
When no device is connected to an attachment point, pulldown resistors ensure
that both data lines are at ground potential. When a device is attached, a pullup
resistor within the device raises one line to above the 2.8V threshold, so the
hub knows that a device is attached. The hub can also tell whether a device
is low or high speed: low speed devices pull up the D- line, while high speed
devices pull D+ high. Having established the presence of a device and its communication
speed, the system software can interrogate it to find out what its requirements
are, and load the relevant drivers for it.
There are similarities between the USB software and the PC Card Socket Services
driver software. There are three software levels. At the lowest level is the
host controller driver (HCD) software that interfaces directly to the USB controller.
Above this is the USB driver (USBD) software that provides USB support for the
operating system the PC is running. Above these two layers is the client software
required for each USB function.
Neither applications nor the operating system can talk directly to USB devices.
Applications may make I/O requests to the client software, or they may access
a USB device indirectly using operating system functions which themselves call
the client software. Client software may either make calls directly to the USBD
layer, or through an operating system defined interface.
The USBD converts client software requests to the bus transaction level, for
example, breaking a request to transfer a large block of data into the requisite
number of packet-sized transfers. These are passed to the HCD layer. The HCD
interacts directly with the USB controller, turning the transaction requests
into a low level implementation dependent form which the controller then responds
to by creating bus activity.
1.1.4. PC - USB Device Communication*
Although a physical map of a USB may look like a tree, logically the bus appears
as a star with up to 127 devices connected to a single hub. Client software
communicates directly with its device. Each device has a unique address, which
is assigned to it by the USB system software during configuration to avoid conflicts.
Communication between devices and client software is conceptualized as using
pipes. Each pipe is a communication channel between software on the host and
an endpoint on a device. Each endpoint represents a part of a device that fulfils
one specific purpose for that device, such as to receive commands or transmit
data. A full speed device can have up to 16 endpoints, though low speed devices
can have only three.
All USB devices support endpoint 0 when powered up. This endpoint is the target
of the default pipe. After the attachment of a device has been detected, the
USBD software uses endpoint 0 to initialize the device, perform generic (i.e.
non device-specific) configuration, and obtain information about the other endpoints
provided by the device. Endpoints are characterized by their endpoint number
(set at design time) and bus bandwidth, access frequency, latency and error
handling behavior requirements.
Once the endpoints of a device have been identified and configured, pipes come
into existence allowing the client software to communicate with the device.
A pipe has associated with it characteristics such as a claim on bus access
and bandwidth, the type of transfer, the direction of transfer and the maximum
data payload size. These terms, however, lie beyond the scope of this article.
At the bottom of this page, you will find links to several complete PDF files
explaining every details about USB.
USB defines four types of transfer: control transfers which are typically used
for command or status operations, interrupt transfers which are initiated by
a device to request some action from the host, isochronous transfers which are
used to carry data the delivery of which is time critical (such as for video
and speech), and bulk transfers which can use all available bandwidth but are
not time critical. All transfers take the form of packets, which contain control
information, data and error checking fields.
There are also two types of pipe: message pipes and stream pipes. Control transfers
are made using message pipes. In a message pipe, the data portion of each packet
has some meaning to the USB system software.
Stream pipes are used for interrupt, isochronous and bulk transfers. In a stream
pipe, the data portion of the packet has no defined meaning to the USB: the
data is merely conveyed between client software and device.
1.1.5. USB: the bad, the ugly, the beauty
In this section, we'll briefly have a look at USB's advantages and disadvantages.
USB is a very flexible, versatile solution. That's what makes it so user friendly.
Just plug your device in an available USB port, install one driver, and that's
it: ready to go! The technique will work in any situation and configuration.
USB is cheap. Prices for a lot of USB devices have dropped significantly the
past few years.
Also, USB can serve your mobility needs. USB Ethernet cards, USB Memory Sticks,
floppy disk drives... It's all available, and since every non-iron age computer
has two or more USB ports, you can use those devices anytime, anywhere.
USB is hot pluggable. This means you can attach and remove devices on the fly
without the need to reconfigure (if you've already installed the device drivers),
nor reboot. More information about hot plugging will be provided later on.
One of the main disadvantages is that USB is a serial technology, what causes
the bandwidth to be distributed between all devices in a linear way. No way
to prevent this issue, unfortunately.
USB allows wires only to be as long as 5 meters. You can extend this length
by using USB hubs to 30 meters, but that really is the maximum.
Another thing is that the technique has not been managed strictly. I mean: take
a look at modems. Only very few work according to the USB Communications Protocol
1.1, since manufacturers tend to use mixtures of chipsets that either don't
support this at all, or only partial, thus limiting these devices only for winusers.
Happily, a lot of manufacturers begin to keep these standards in mind. Most
recent USB Memory Keys, for example, support the USB Mass Storage Device (MSD)
Standard, thus extending their market to users of other, and better, OS'es.
1.2. Some common USB Terminology...
There are many reasons why USB is inferior to other technologies like e.g.
SCSI, but that will not be discussed in this article. Fact remains that, despite
of its limited performance (and this performance limit doesn't matter with today's
modern Hi-Speed USB 2.0) USB is a great technology, since it combines ease of
use, compatibility with all major operating systems, and especially mobility
(USB memory keys, USB Ethernet NICs).
Unfortunately, there often seems to be some misunderstanding related to USB
terminology when discussing the Universal Serial Bus technology. That’s
why a brief and clear overview is given here:
|Port for attaching USB printers, scanners, mice and digital
cameras. Maximal transfer rates of 1 ½ Mbps. This variant of USB
is also referred to as “low speed USB”; maximum of some 700KBps.
USB 1.0 is practically non-existing, and USB 1.1 is present everywhere.
1.1 is called “full-speed” USB and has rates of 12Mbps, that
is a little lit less than 1 ½ MBps.
|New port for attaching USB printers, scanners, mice and digital cameras
(planned to be replacement of USB 1.1).
Maximal transfer speed of 480Mbps or 60MBps (40 times faster as USB 1.1).
If you attach a USB 1.1 device on a USB 2.0 controller, then that device
will function correctly, but at USB 1.1 transfer rates. IF YOU PURCHASE
A DEVICE WITH USB 2.0, THAT DOESN’T ALWAYS MEAN YOU GET HI-SPEED
(480Mbps)! USB 2.0 contains all existing speeds: low (1 ½ Mbps),
full (12Mbps) and high (480Mbps).
|Addition to USB 2.0: USB On-The-Go. Peer to peer USB; using this technology,
USB devices can communicate with one each other without intervention of
|New standard for USB devices. Increases the data transfer rates from
12Mbps to 480Mbps (60MBps) on Hi-Speed USB controllers.
Backwards compatible with the original USB; uses the same wires!
|New port for branching devices, in particular video devices. At present,
hardware manufacturers tend to release other devices for this bus. Sony
accepts this technology under the name iLink. 12 ½ to 50 MBps.
This technology is very similar to that of USB, but it is something quite
So far for a brief overview of technologies. Now, in the "USB technology
family", there are some variants, types of Host Controller Interfaces:
First, for USB 1.1 (or for USB 2.0 cards that can also use USB 1.1 devices),
we have UHCI and OHCI.
UHCI is short for Universal Host Controller Interface. It is one particular
direction in the USB controller interfaces. It is used by Intel and VIA chipsets.
Other brands also can be compatible with UHCI. This is the real standard for
USB 1.1. nVidia nForce is also UHCI. UHCI, Intel’s proprietary interface,
defines how the USB controller talks to the host computer and its operating
system. UHCI is optimized to minimize host computer design complexity and uses
the host CPU to control the USB bus.
A kind of equivalent of UHCI is OHCI, Open Systems Host Controller Interface.
It's another particular direction in USB 1.1, and is mainly used in chipsets
branded by SiS, ALi, Opti and Cyrix (Gnode), Agere Systems, Silicon Core. OHCI,
jointly developed by Compaq, Microsoft, and National Semiconductor Corporation
and backed by more than 25 companies, defines the register level interface that
enables the USB controller to "talk" to the host computer and its
operating system. OHCI defines an industry standard hardware interface for operating
systems, device drivers, and the basic input output system (BIOS) to manage
the USB. OHCI optimizes performance of the USB bus while minimizing central
processing unit (CPU) overhead to control the USB. USB devices don't care whether
you're using an OHCI or UHCI controller; you can use all devices on any kind
Then, there is EHCI: Enhanced Host Controller Interface. This is a direction
that enables USB 2.0, more to say USB Hi-Speed. The two-direction market as
exists for USB 1.1 is not present here; all controllers use the same specific
One thing you should very well be aware of is that USB is a serial technology.
That means that the maximum bandwidth (12Mbps for USB 1.1, 480Mbps for USB 2.0
Hi-Speed) is divided between all USB ports. This also applies to USB Hubs, where
this issue should be accounted for more seriously. This problem will be discussed
thoroughly in the article about USB hubs; for regular PCI USB controllers, with
only a limited number of ports, there should not be any real problems, unless
you are using several fast devices, like USB 2.0 harddisks, USB 2.0 Memory Keys,
USB Audio, and USB Ethernet cards simultaneously. The problem is even more present
on USB 1.x controllers. But remember that if you use a lot of USB devices at
the same moment, this unavoidably leads to a performance degradation.
All of these variants are supported using OS/2 Base USB Device Drivers (EHCI.EXE).
Perhaps your (onboard) USB controller is supported, but you thought OS/2 didn't
support it, because some years ago, only UHCI controllers were supported. Recently,
that changed: any recent USB controller, whether it is USB 1.1 or 2.0 Hi-Speed
should be compatible.
Over the years especially Intel and VIA solutions became very wide-spread, and
recently, NEC's µ7201 chip is the standard for PCI USB 2.0 cards. Next,
we'll give a brief overview of the most popular chipsets used on USB controllers.
Controllers that are, of course, compatible with OS/2.
For OHCI, there are the CMD chipsets: USB0670 and USB0673 chipsets, USS-302
from Lucent Technologies and OPTi 82C861. Most SiS, ALi, and Cyrix (Gnode) chips
are also supported.
For UHCI, all Via and Intel chipsets are compatible. Intel has two very popular
and wide-spread chips, the 440BX an 440LX. Also nVidia's nForce is UHCI and
works smoothly with OS/2.
For EHCI, the main chipsets available today are the NEC µ7201 and the
VIA VT6202. These chipsets have also a USB 1.1 aspect for the backwards compatibility,
described above: the NEC also supports OHCI, and the VIA UHCI. Without this
feature, the USB controllers wouldn't be able to use USB 1.1 devices.
Of course, a lot more chipsets exist, but this section's goal was to list the
most popular compatible chipsets. Special mixtures of several unknown chipsets
will most probably not work. The table* below lists all chipsets tested by OS/2
||USB 1.1 OHCI
||USB 1.1 UHCI
|Intel 82865PE (MCH)
|Intel i82801DB ICH4
|Intel i82801DBM ICH4-M
|Intel Springdale-G 865G ICH5
||Intel i82371AB southbridge (PIIX4)
|NEC µ7201 family
||Intel i82371EB southbridge (PIIX4E)
||Intel i82801AA ICH
||SiS SiS630S southbridge
||Intel i82801CA ICH3-S
||Intel i82801CAM ICH3-M
||VIA VT82C596B southbridge
||VIA VT82C686A southbridge
||VIA VT82C686B southbridge
* Note that the chipsets listed in the USB 2.0 column also support USB 1.1;
no entries for the USB 1.1 compatibilities are added to the table.
2. Base USB Device Driver Installation
The IBM USB Basic Device Driver, also called USB Stack, comes in a self-extracting
file. The official driver is available via IBM SoftWare Choice or IBM PassPort
Advantage subscriptions, and can be downloaded from the IBM OS/2 Device Driver
Pack Online. eComStation 1.0 and 1.1 also include these drivers. An older version
that only supports UHCI can be downloaded from the OS/2 Warp USB web site.
In order to use this driver, your computing system must meet the following requirements:
- OS/2 Warp 3, OS/2 Warp 4 Merlin, OS/2 Warp Server for e-business Aurora,
MCP1 or ACP1, MCP2 or MCP2, eComStation 1.0 or higher;
- Any PCI to USB Host Controller compatible with USB 1.1 or USB 2.0 specification
and using UHCI, OHCI or EHCI interface. Only PCI-to-USB controllers are
supported, it is not worth the effort to try PCMCIA USB controllers; they
will not work.
In fact, this self-extracting file contains three separate drivers; one for
EHCI (USBEHCI.SYS), another for OHCI (USBOHCI.SYS), and again another for UHCI
(USBUHCI.SYS). The USBBASIC.EXE file, once executed, will extract seven files:
the three drivers just mentioned, an underlying driver (USBD.SYS),
the USB Human Interface driver (USBHID.SYS), the Host Controller adapter(s)
monitor utility (HCIMONIT.EXE), an installation utility (USBINST.EXE) and USBBASIC.TXT,
a limited readme.
2.1. Regular IBM OS/2 Warp
2.2.1. USB-Basic Installation Instructions
To install the USB device drivers manually, proceed as follows:
- To obtain the required USB driver files, you must expand the USBBASIC.EXE
file into its 7 component files by downloading the USBBASIC.EXE file from
the DDP OnLine web site (or elsewhere), and do one of the following possible
- Via WarpCenter or XCenter, browse to the directory where you downloaded
the driver, and right-click the directory to open it in a window.
Double-click on the USBBASIC.EXE icon. Now the files will be extracted.
- Open an OS/2 Command Prompt, change the active directory to the
directory where you stored the self-extracting file, and type usbbasic.
- Before you continue with USB driver installation, you should examine
if the drivers support your controller. This can be accomplished using
a very straight-forward utility, HCIMONIT.EXE, the Host Controller adapter(s)
monitor utility. It reports the number of UHCI, OHCI and the number of
EHCI controllers on your system. If no UHCI, OHCI or EHCI controllers
are reported, do not install USB drivers, since either the USB controller(s)
are not supported, or there are IRQ conflicts or other hardware problems.
The hardware monitor tells you how many controllers it has found with
for each type of Host Controller Interface a line of the form: "You
have x USB yHCI PCI host controller(s)", where x is the number of
yHCI controllers found, and y is the appropriate letter for EHCI, OHCI
or UHCI. If HCIMONIT.EXE fails to find controllers, it reports: "No
controllers found!" If controllers have been reported, then you can
continue with installation. Otherwise, contact OS/2 CHL Technical Hardware
To run the monitor, from an OS/2 Command Line, where the active directory
is the directory where you extracted USBBASIC.EXE, type hcimonit,
and press ENTER.
- From the OS/2 command prompt, type usbinst. If no support
for USB had been installed, USBINST will automatically configure the system
to add basic USB support; on the other
hand, if you have already installed USB on your PC, the program will refresh
USB support on your PC. By running this command, installation is finished
and a reboot is required before you can start using USB. Note that you
can install other USB drivers before rebooting
Unlike the powerful USB support in eCS 1.1, eCS 1.0 and the IBM Convenience
Packages do install and configure the USB device drivers, but by default, they
are REMmed out in config.sys. The USB stack must first be added to the OS/2
Installation diskette labeled "Diskette 1" if you want to use USB
peripherals like floppy disk drives, mice and keyboards during installation
or when booting from diskette.
If you haven't got boot diskettes, first make them by running cdinst.cmd from
the OS/2 Warp installation
cd-rom (or the second cd for the Convenience Packages). You will then be prompted
to insert floppies and the program will guide you through the process. Then,
refer to the README with the basic USB device driver package for instructions
on updating the diskette for the devices.
2.2. eComStation 1.1
Even though eComStation 1.1 uses the very same IBM drivers as MCP, and these
drivers offer the same potential of functionality, the eCS crew working on the
installer have performed a great job. During this installer, a lot of options
can be chosen in that you will have less work later with configuring the individual
drivers. This section will only discuss basic USB support installation using
the eCS 1.1 installer. If you need to change your USB configuration once eCS
has already been installed, you should act as described in the previous section.
Right from the very first phases of the installation, the installer reflects
that extreme powerful USB support is present. This is a great improvement compared
to IBM's CP2 (Convenience Pack 2) strategy, where USB drivers are copied to
disk, but are by default REMmed out of config.sys.
The image above shows the third page of the boot options menu. You can get
to it by booting from the eCS cd-rom, and selecting boot with menu for own
values. Then, you will be guided towards the eComstation BOOT OPTIONS:
Keys Help menu. Press ENTER. The eComstation BOOT OPTIONS:
Miscellaneous menu appears. Here you can set the codepages, choose which
installer you want to use, and set some drive letters. By pressing ENTER,
you will get to the screen eComStation BOOT OPTIONS: Storage, where
driver options for your controllers, which should be auto-detected, can be set,
and drivers can be selected for other controllers that were not detected. By
again pressing ENTER, you will get to the screen eComStation BOOT
OPTIONS: USB, as showed in the image above. Navigate to the appropriate
fields by using the tab button and change the options if necessary. Normally,
you shouldn't need to change anything, since USB devices are detected automatically.
For each kind of controllers (EHCI, OHCI, UHCI), you can select a maximum of
four controllers (mind it; controllers, not ports; a controller has several
ports). Using the tab button, navigate to the appropriate fields, and use the
up/down arrows to specify the number of USB controllers in the first three fields.
Please keep the remark at the end of this section in mind when specifying this
number! You can have EHCI, OHCI and UHCI controller support installed simultaneously,
so in theory you can use up to 12 USB controllers. Only if at least one USB
host controller is selected, you can modify the last fields. By default, these
last three options are deselected. Navigate towards the appropriate fields and
press space bar to enable support for these devices. If enabled, a V-sign appear
between the brackets. The last option, Support USB mass storage devices:
has a submenu where you must use the arrows too to specify the number of those
USB devices attached to your computer. If you haven't got them, set the number
to zero, otherwise select the appropriate number. As was the case for controllers,
you can only specify a maximum of four USB floppy disk drives and CD-R(W) devices.
Please note that the Support USB mass storage devices: does not install
IBM's latest USB MSD driver, so it won't allow you to use USB memory keys; for
that, you should install IBM's driver version 1.3 or higher, which can be downloaded
from the eComstation web site. Now you have finished the first steps of eCS
1.1 installation. To continue, you must confirm the choices you made, by pressing
F10. After some seconds, the graphical installer will appear.
In the image above, you can see the Hardware and peripherals windows
from the eCS 1.1 installer. Here, you can review the choices you already made
in the eComStation BOOT OPTIONS: USB menu, and also install support
for non-USB technologies. Additionally, you can specify any extra USB devices
you want to have support installed for by checking the appropriate checkboxes
for CD, floppy disk drive, or modem. If you had specified USB controllers in
the eComStation BOOT OPTIONS: USB menu, then the current window will
reflect your choices. Also, if you had selected floppy disk drives attached
under the menu Support for USB mass storage devices:, then this option
will already be selected.
From this window, several options can be specified for the USB device drivers.
To do so, just click a subentry in the USB Support entry, click in
the field Additional parameters near the bottom of the screen, and
type the options you wish to add in your config.sys. The options for USB controllers
will be covered in the next section of this article, other options will be covered
in later articles. Once you're finished with this window of the installer, click
Next> to continue with installation.
As usual, OS/2 prefers a unique IRQ for the USB host controller.
Even though the IBM USB device drivers were developed to support shared interrupts,
in practice, it's best to assign it a unique, legacy IRQ. Experience has learned
that it is best to assign your USB controller an IRQ below 6. Of course, other
IRQs can also be used, but for some reason problems can occur with higher ones.
Recommended is to use IRQ4, thus disabling one of your serials ports.
Something very important is that for each pair of USB ports on a controller,
a line specifying the appropriate device driver must be added in your config.sys.
For example: a six-port controller requires you to have three lines in your
config.sys (or even more if it's USB 2.0: two lines for each pair: one for the
driver used for USB 1.1 devices; the other for USB 2.0). If you've got a controller
with an odd number of USB ports, then increment the number of cards by one,
and take that number to decide how many copies of the driver line should be
present in config.sys.
2.3. USB Device Driver Options
There are some config.sys device driver options that come in handy. We'll briefly
take a look at them, and discuss whether or not these settings are useful.
BASEDEV=USBD.SYS [/I13] [/REQ:USBUHCD$,USBOHCD$,USBEHCD$] [/V]
This option allow you to boot from USB devices. Best to add it in config.sys.
This switch is also required if you want to boot from USB hard disk drives,
floppy drives, memory keys, and other USB mass storage devices.
This switch is some kind of "error protection". It makes sure
that the USBD.SYS driver is not loaded when no drivers are loaded for EHCI,
OHCI, and/or UHCI controllers. It does impose a very important limitation:
the config.sys lines for USBEHCI.SYS, USBOHCI.SYS, and USBUHCI.SYS must
be before the USBD.SYS line in your config.sys, otherwise, since OS/2 processes
its config.sys top-down, USBD.SYS won't be loaded because the xHCI.SYS drivers
are only loaded afterwards it. Using this switch, one of the drivers should
be initialized before OS/2 will initialize USBD.SYS. If none were initialized,
USBD.SYS won't be loaded. Caution! Mind it to append the EXACT option described
above to your config.sys; otherwise, you'll see "Invalid config.sys
option" at config.sys. Fortunately, if that's the case, the bad option
is ignored and the drivers are loaded appropriately, though without this
option. Note the $-signs; normally, an OS/2 device is called by the system
and applications by a driver name, followed by a dollar sign. Thus, a UHCI
controller is called with USBUHCD$, a OHCI one by USBOHCD$, and an EHCI
one by USBEHCD$. Nice to be confronted with internal driver details, not?
Recommendation: append this option to the appropriate line(s) in your config.sys.
BASEDEV= EHCD.SYS|OHCD.SYS|UHCD.SYS [/FS] [/V]
In each line of your config.sys, you can only pick one of these. Of course,
when specifying several different lines, you can pick a selection of them.
Note that one line only supports up to a set of two USB ports from a controller.
If you've for, for example, a controller with five UHCI ports, then you
must have three lines "BASEDEV=UHCD.SYS /V" in your config.sys!
Forces driver to stop USB host when shutting OS/2 down. This parameter can
be used to prevent POST (power on system test) failure on some hardware
with legacy keyboard. Recommendation: don't use it! This option can only
cause a lot of problems in modern computer systems.
And then, applicable to all of the drivers above, the /V option forces the
driver to display its initialization information. Doing so, during boot, you
will get to the the IRQ and I/O addresses from the controller(s) detected.
When specifying these option in the Additional Options field using the eCS
1.1 installer, don't type the beginning of these statements. The only options
you may type there are /FS; /REQ:UHCD$,OHCD$,EHCD$; I13 and /V. To avoid problems,
always put the /V option as last switch.
3. What you should think of when choosing
a USB controller card
This is rather straightforward, actually. With today's
extreme low prices for USB controllers, pick one out that is USB Hi-Speed 2.0.
You can keep using your existing USB 1.0 or USB 1.1 devices, and in meantime
make use of devices like external hard disks that can use USB 2.0's 480Mbps
data transfer rate. If you can, go for a controller with the NEC µ7201
(EHCI + OHCI) chipset, which offer much greater performance than the equivalent
VIA6202 (EHCI + UHCI) chipset. Taken a look at the design and principles of
OHCI compared to UHCI, go for OHCI, since this technology uses less CPU time,
thus increasing performance. This is also the reason why I advice you to buy
USB 2.0 controllers with the NEC7201 chipset (EHCI and OHCI) instead of the
VIA VT6202 (EHCI and UHCI). Most new USB controllers are available as add-on
PCI cards. However, should you plan to purchase a brand-new computer, then ask
your local vendor for a PC equipped with a motherboard with USB 2.0 ports. An
on-board controller is a far more elegant solution, and it doesn't waste a PCI
Where USB 1.1 controllers normally came with a default maximum of two ports,
a lot of newer controllers, especially 2.0, come with five to six ports. If
you want to make intense use of OS/2's USB support, then the best thing would
be to purchase a PCI card, since manufacturers tend to impose a limit of a maximum
of four ports with on-board controllers.
Nevertheless, OS/2 should support any USB controller available today. One remark
I'd like to make is not to use PCI boards with both USB and FireWire ports.
I've tried one once, and the card took one IRQ for each technology, and at this
moment you just can't use FireWire with OS/2.
4. OS/2 CHL Tested USB Controllers
The following devices have been tested by OS/2 CHL team and have been found
100% compatible with OS/2 and eCS. For the most up-to-date listing of tested
devices (this is only subset of those in the list), please consult the OS/2
CHL (www.os2warp.be), where you'll also find the appropriate chipsets using
in each device.
All USB 1.1 devices should work perfectly with IBM's Convenience Packages and
eCS. For USB 2.0 devices, if using something else than eCS 1.1, it is recommended
to update the USB device drivers to the most current level of IBM's USB base
|A-Best Ltd. USB-200 PCI adapter
|Adaptec, Incorporated AUA-5100B 6-port USB 2.0 Controller PCI
|Adaptec, Incorporated AUA-5100 USB 2.0 Controller (5-port) PCI
|Adaptec, Incorporated USB 2.0 Upgrade Kit PCI
|Adaptec, Incorporated USB2Connect Adapter Card AUA-3100LP USB 2.0 Controller
|Adaptec, Incorporated USB2connect 4-Port Controller AUA-4000A USB 2.0
|Adaptec, Incorporated USB2connect 4-Port Controller AUA-4000B USB 2.0
|ADS Technologies USBX-500 PCI
|ADS Technologies USBX-501 PCI
|Alchemy Technology Inc. PCI-to-USB Card
|ALi Corporation ALi PCI to USB 2.0 Enhanced Host Controller on-board
|Amedia Microsystems Corp USB Simply Connect PCI
|Asus PCI-USB2 OHCI PCI controller
|BAFO BF-460 5-port USB controller PCI
|Belkin Components BusPort USB F5U005 PCI
|Belkin Components HiSpeed F5U220 PCI USB 2.0
|CamTel USB-PCI Card
|D-Link DSB-500 PCI USB controller
|D-Link Systems DU-A2 PCI USB controller
|Entrega Technologies Inc. PCI4U 4Port USB Upgrade
|Entrega Technologies Inc. USB upgrade PCI card w/ 2 ports #upg-pci-2P
|Gigabyte GC-USB20N PCI Expansion Card 4-port USB controller
|GWC UC-160 5-port (4+1) USB 2.0 high-speed add-on PCI controller
|Intel i82801AA USB Universal Host Controller on-board (ICH)
|Intel i82801CA USB Universal Host Controller on-board (ICH3)
|Intel i82801CA USB Universal Host Controller on-board (ICH3-S)
|Intel i82801CA USB Universal Host Controller on-board (ICH3-M)
|Intel i82801CAM USB Universal Host Controller on-board
|Intel i82371AB PCI to USB Universal Host Controller on-board (PIIX4)
|Intel i82801DB ICH4 USB host controller on-board
|Intel i82801DBM ICH4-M USB host controller on-board
|Intel i82371EB PCI to USB Universal Host Controller on-board (PIIX4E)
|Intel 845 based motherboard with built-in USB 2.0 chipset on-board USB
|IOGEAR CIC220U USB 2.0 PCI Card
|IOGEAR GIC250U 5-Port USB 2.0 PCI Card
|IOGEAR G2XC01 USB 2.0 PCI Card
|Jameco PCI USB I/O card part# 155299 PCI
|Keyspan U2PCI-5 5-port PCI USB 2.0 controller
|Manhattan Computer Products 166911 PCI USB 1.1 4 Port Card
|Manhattan Computer Products 167741 PCI USB 2.0 2 port card
|Manhattan Computer Products 169011 PCI USB 2.0 3+1 port card
|Multi-Ports5 Port PCI to USB 2.0 High Speed Card Adapter
|Multi-Ports PCI USB 1.1/2.0 Card SIMT023A MUL-PCI5PORTUSB20
|Mentor USB 2.0 PCI Card 4-Port Adapter
|National Technology Inc. UC-100 PCI
|OPTi Inc 82C861 PCI to USB Open Host Controller on-board
|Orange Micro Inc. OrangeUSB 2.0 PCI 4-port controller
|Orange Micro Inc. Low Cost USB 2.0 PCI 2-port controller
|PPA Inc. 5 Port USB 2.0 480Mbps Interface Card PCI 40X 4 Ports
|SIIG USB DualPort PCI JU-P20012
|Silicon Integrated Systems Corp SiS630S USB host controller on-board
|Silicon Integrated Systems Corp SiS735 USB host controller on-board
|Silicon Integrated Systems Corp SiS745 USB host controller on-board
|Silicon Integrated Systems Corp SiS7001 PCI to USB
|Silicon Integrated Systems Corp SiS7002 USB 2.0 Enhanced Host Controller
|Soltek SL-02USB 4-Port USB 2.0 High Speed Card PCI
|Soyo PCI TO USB 2.0 4-Port Controller
|TekRam DC-602W, 4 External Port, 1 Internal USB 2.0 Port
|TekRam DC-602T, 3 External Port, 1 Internal USB 2.0 Port
|TekRam DC-602B, 2 External Port, 1 Internal USB 2.0 Port
|USB2JET Host Controller PCI USB 2.0 3 Port card
|USBWholesale UP-205 U2PCIBY 5-port PCI USB 2.0 controller
|VIA Technologies Inc. VIA USB Universal Host Controller (VT82C596B)
|VIA Technologies Inc. VIA USB Universal Host Controller(VT82C686A) UHCI
|VIA Technologies Inc. VIA USB Universal Host Controller(VT82C686B) UHCI
|VIA Technologies Inc. VIA VT6202 PCI USB 2.0 4-port Host Controller
|Ratoc PCIU5 2-port USB 2.0 PCI controller
5. And what about Linux?
this moment only USB 1.1 (OHCI and UHCI) support is fairly complete. Almost
every chipset should be able to work. USB support was first introduced in kernel
release 2.2.18. For now, USB 2.0 (EHCI) is still under development, but it should
work fine with most controllers. USB 2.0 EHCI support has been introduced in
kernel release 2.4.18 but will have full support in the new kernel 2.6. The
NEC implementation of EHCI (NEC µ7201) seems to have a hardware bottleneck
at around 28 MByte/sec aggregate transfer rate. While this is clearly enough
for a single device at 20 MByte/sec, putting three such devices onto one bus
does not get you 60 MByte/sec.
You can find a list of tested devices at http://www.qbik.ch/usb/devices/.
All chipsets from chapter 1.3 should be supported, except for the NEC µ7201.
For more information about Linux and USB, visit http://www.linux-usb.org/.
The Universal Serial Bus technology provides a versatile,
flexible method of connecting a wide range of low- and medium-speed peripherals
to a PC at relatively low cost. Its plug-and-play configuration means that the
installation and support of peripherals is much easier compared with devices
using the serial, parallel or proprietary interfaces. Of course, compared to
professional technologies like SCSI, USB is inferior. All these advantages make
the technology well-suited for both home and business use. USB controllers are
the basis of USB technology. They allow you to use USB devices using additional
device drivers. IBM's basic OS/2 USB device drivers offer great support for
a very diverse set of devices; all PCI EHCI, OHCI and UHCI controllers should
be supported, and also on-board controllers should be supported.
(*): This section is a derived version of an article that appeared some years
ago in PC Support Advisor. Although it provides a good general introduction
to USB concepts, some of the details are left out since they are not relevant
for general daily use of OS/2 USB device drivers.