Simple Step-by-Step Tips for Installing Your Adaptec PCI Card

Congratulations on your Adaptec purchase! On this page we're going to help you get your new Adaptec PCI card installed. In just a few easy steps you'll be up and running. The process is rather straight forward and should be no trouble for you even if you've never opened your computer.

Find a clean dry place and let's get started. You may want to view the demonstration video a few times before trying it yourself as it will get you acquainted with the process and what to expect

First, turn off your computer power, unplug it from the wall and refer to your user's manual for instructions on how to open the back of your computer.
Remove the card from its protective sleeve, being careful to hold the card by brackets only, and not to touch the gold connectors on the bottom edge of the card.
Make sure to touch a bare metal surface on the back of the computer, ensuring that you are static free and
Next, locate the PCI expansion card bracket. This is where you will install the card.
Remove the screw that attaches the expansion card bracket to the case, then remove the bracket.
Take the card and line up the gold connectors with the PCI slot, ensuring that the ports and the bracket are facing the back of the computer.
Now, press the card into the slot, making sure that you push evenly on both edges until the card is firmly seated. You can slightly see-saw the card end-to-end as you work it into the slot, but do not bend the card sideways. When the card is correctly installed, it will “click” into place.
Secure the card to the computer case with the screw you removed earlier. The bracket should now fit snugly to the outside of the case.

That's it! You have successfully installed your Adaptec PCI card. Once you've closed up the computer case, please refer to your software instructions manual on how to install your software. Enjoy, and thank you for your Adaptec purchase

Differential SCSI

SCSI devices use Single-Ended (SE), Low Voltage Differential (LVD or Ultra2), or High Voltage Differential (HVD) electrical interfaces between the device and host adapter. A single-ended interface uses one wire for each data or command/status line, with a corresponding ground wire for that signal. Voltage is carried only on the signal line.

A differential interface uses signal transmitters and receivers to drive the signal over longer distances and for noise rejection. The signal is split into positive and negative components and transmitted over cable pairs. Voltage is carried on both wires. The signal is re-combined at the receiving device. If a single-ended device such as a CD-ROM is connected to a differential host adapter (e.g., AHA-2944UW), or a differential device (e.g., a hard drive with a D suffix or differential tape drive) is connected to a single-ended host adapter such as the AHA-2940UW, irreparable damage can be done to either or both devices. Adapters are available from third-party suppliers which adapt differential devices to single-ended uses. These third party adapter configurations are not supported by Adaptec.

Low Voltage Differential (LVD) devices are also known as ULTRA2 and should be used only on multi mode adapters which support ULTRA2 and/or SE devices.(The AHA-2930U2, AHA-2940U2W, and AHA-3950U2 support both LVD and SE devices).

Accessing your SCSI CDROM under DOS

This utility will assist you creating a bootable diskette which will include drivers for your SCSI Host Adapter and SCSI CD-ROM drive.

Please select your SCSI Adapter model AVA-290x AIC-78xx AHA-291x / 2930C / 2930CU AHA-294x / 2940UW / 2940UW Pro AHA-2940U2W / 2930U2 / 3950U2B AIC-7890 AHA-2920C-(Only) AHA-2920 / 2920A AHA-154x / 164x AHA-174x-(Standard Mode) AVA-150x / 2825 AIC-6260 / 6360 / 6370 AHA-151x / 152x / 153x AHA-274x / 284x AIC-7770 AHA-174x-(Enhanced Mode) APA-358 / 358A T358
  1. Create a bootable diskette. In DOS use the format a: /s command. In Windows 95/98 right click on the drive letter displayed under My Computer and choose "Format". Verify that the "Copy System Files" checkbox is selected.
  2. Download DOSDRVR.EXE and save it in the floppy disk just formatted.
  3. After downloading, execute the DOSDRVR.EXE file. As a result, several files will be decompressed.
  4. Copy the file named MSCDEX.EXE to the diskette. This file is part of the Operating System. In Windows 95/98 it can be found in the \windows\command directory. Under MS-DOS it can be found in the \dos directory.
  5. Create a blank text file using Notepad or Edit and paste the lines listed below in it. Save the file as A:\CONFIG.SYS.

Please select an Adapter above

  1. Create a blank text file using Notepad and paste the lines listed below in it. Save the file as A:\AUTOEXEC.BAT

Please select an Adapter above

  1. Leave the diskette inserted in the floppy drive and restart the computer. The CD-ROM drive will get assigned the next drive letter available. If the computer does not boot from the diskette, check your CMOS Setup to verify that the computer is set to boot from the diskette first before booting from the hard drive. For additional information please refer the README.TXT file that is part of DOSDRVR.EXE. Regarding MSCDEX.EXE type MSCDEX /? at the command line.

Windows 98 issues

Known Issues

  • In some cases, each channel of a MultiChannel adapter must be updated/installed manually with the aic78xx.mpd driver on a freshly installed Windows 98 system. Please follow the instructions listed under Updating the Driver for Windows 98 for each channel.
  • Real mode ASPI drivers from EZ-SCSI are not needed, because Windows 98 miniport drivers support most SCSI host adapters and SCSI devices. However, you will need to load the ASPI drivers (including MSCDEX.EXE, if you have CD-ROM drive) if any of the following are true:
    • You are running in MS-DOS mode and need to access your CD-ROM drive.
    • You are using a scanner or another SCSI device with CONFIG.SYS or AUTOEXEC.BAT based drivers, such as HP's SJIIX.SYS.
    • You have an older model SCSI-1 CD-ROM driver that Windows 98 does not support.
    • You are using a CD-Recorder drive (however, some newer models of CD-Recorder drives can use the embedded Windows drivers).
  • Some older models of SCSI CD-ROM drives are not compatible with the embedded Windows 98 CD-ROM driver. You can add support for the CD-ROM drive by doing the following:
    1. Make sure your ASPI real mode drivers (including ASPI8DOS.SYS, ASPICD.SYS and MSCDEX.EXE) are loaded and running from your CONFIG.SYS and AUTOEXEC.BAT files. Consult your EZ-SCSI installation guide for more details.
    2. If step 1 did not work, find the file named CDTSD.VXD in the \windows\system\iosubsys directory and rename it to CDTSD.SAV.
  • The mapping between MSCDEX.EXE, which runs in real mode, and the Windows 98 CD-ROM driver does not match. You can correct this in one of two ways:
    1. Comment out the line that loads mscdex.exe in the autoexec.bat file.
    2. Change the /L switch on the line that loads mscdex.exe in the AUTOEXEC.BAT file so it assigns the CD-ROM drive the next highest logical drive letter after the hard disk drives.
  • Windows 98 does not support sharing of system interrupts (also known as IRQs) between two or more I/O subsystem devices (i.e. network interface cards or hard disk adapters such as SCSI host adapters). When IRQs are shared between I/O devices, lockups can occur while booting. If lockups occur, try moving or removing one or more PCI cards from one slot to another and bootup your computer again. If problems continue, refer to your system documentation and/or your system technical support for information on adding your system configuration.
  • When updating/installing the driver for a host adapter, the Family Manager Set will not automatically install both Ultra2 and Ultra/Fast drivers. If you require both drivers, you will have to install them seperately, as per individual host adapter. For example, after installing the driver for the AHA-2940U2W, there may be a conflict in the Device Manager with an existing or newly-installed Adaptec UltraSCSI or earlier host adapter. To resolve this problem, simply update the driver for the conflicting host adapter with the Family Manager Set v3.02.2 driver from the Device Manager.



All information below can be obtained from the Users Guide of the host adapter.

Note: All default settings are listed with an asterisk "*".

Host Adapter Interrupt (IRQ) Channel

This option determines the host adapters IRQ channel for non Plug and Play adapters. The default is 11.

Host Adapter DMA Channel

This option determine the DMA (Direct Memory Channel) for non Plug and Play adapters. The default is 5.

Host Adapter SCSI ID

This option sets the host adapter's SCSI ID. The default setting is SCSI ID 7, which gives the host adapter the highest priority on the SCSI bus. It is recommended that you leave the host adapter set to SCSI ID 7.

SCSI Parity Checking

This option determines whether the host adapter verifies the accuracy of data transfer on the SCSI bus. The default is Enabled. You should disable SCSI Parity Checking if any SCSI device, connected to the host adapter, does not support SCSI parity.

DMA Transfer Rate

This option determines the DMA transfer rate for ISA bus mastering host adapters. The default is 5.0 MBytes/sec. [Note: Leave this option set to default unless the computer documentation clearly states that it supports higher DMA transfer rates. Running the host adapter faster than the computer can cause intermittent errors. Always backup your data before increasing the transfer rate.]

Host Adapter SCSI Termination

This option sets termination on the host adapter. The default, on most host adapters is Automatic. Other host adapters will list Host Adapter SCSI Termination as Enabled.

Other possibilities for Automatic settings:

Enabled - Internal devices only.
Enabled - External devices only.
Disabled - Internal and external devices.

On   On      68-pin internal connector only 
On   On      68-pin external connector only 
Off  Off     68-pin internal and 68-pin 
                external connectors 
On   On      50-pin internal connector only 
Off  On      50-pin and 68-pin internal 
Off  On      50-pin internal and 68-pin 
                external connectors 

Boot Device Settings

The Boot device Settings allows the user to specify the device they wish to boot the system from.

Boot target ID: This option specifies the SCSI ID of the device to boot from. The default setting is SCSI ID 0. The SCSI ID selected here must correspond to the ID configured on the boot device.
Boot LUN Number: If the boot device has multiple LUNs ( Logical Unit Numbers) and Multiple LUN support is enabled, this option allows the user to specify which LUN to boot from your boot device. The default is 0.

SCSI Device Configuration

This area define configuration settings that are specific only to the SCSI ID of the device in question. Settings changes of one device will not effect the operational characteristics of another device.

Initiate Sync Negotiation

This option determines whether synchronous data transfer negotiation (Sync Negotiation) between the device and host adapter is initiated by the host adapter. The default is Yes. Synchronous negotiation is a SCSI feature that allows the host adapter and its attached devices to transer data in synchronous mode. Synchronous data transfer is faster than asynchronous data transfer. The host adapter always responds to Sync Negotiation if the SCSI device initiates it. If neither the host nor the SCSI device initiates Sync Negotiation, data is transferred asynchronously. [Note: Some older SCSI-1 devices do not support Sync Negotiation. This may cause your computer to operate erratically or hang if Initiate Sync Negotiation is set to yes. Set Initiate Sync Negotiation to No for these devices.]

Initiate Wide Negotiation

(For Adaptec host adapters with wide capabilities only) This option determines whether the host adapter attempts 16-bit data transfer (Wide negotiation) instead of 8-bit data transfer. The default is Yes. [Note: Some 8-bit SCSI devices may have trouble handling Wide Negotiation, which may result in erratic behavior or a hang condition. For these devices, set Initiate Wide Negotiation to No.] When set to Yes, the host adapter attempts 16-bit transfer. When set to No, 8-bit data transfer is used unless the SCSI device itself requests Wide negotiation. The effective transfer rate is doubled when 16-bit data transfer is used because the data path for Wide SCSI is twice the size of normal 8-bit SCSI.

Maximum Sync Transfer Rate

This option sets the maximum data transfer rate that the host adapter supports. If the host adapter is set not to negotiate for synchronous data transfer (that is, Initiate Sync Negotiation is set to no), then the maximum synchronous transfer rate is the maximum rate that the host adapter accepts from the device during negotiation. (This is standard SCSI protocol.)

Enable Fast SCSI

(AHA-154XCF and AHA-154XCP) This option sets the maximum data transfer rate that the host adapter supports. The default settingis No on the AHA-154XCF and Yes on the AHA-154XCP. If the host adapter is set not to negotiate for synchronous data transfer (that is, Initiate Sync Negotiation is set to no), then the maximum synchronous transfer rate is the maximum rate that the host adapter accepts from the device during negotiation. (This is standard SCSI protocol.)

Enable Disconnection

This option determines whether the host adapter allows the SCSI device to disconnect from the SCSI bus (sometimes called Disconnect/Reconnect). Enabling disconnection allows the host adapter to perform other operations on the SCSI bus while the SCSI device is temporarily disconnected. The default is Yes. You should leave Enable Disconnection set to yes if 2 or more SCSI devices are connected to the host adapter. This optimizes SCSI bus performance.

Send Start Unit Command

This option determines whether the Send Start Unit Command is sent to the SCSI device at bootup (most devices do not require this). The default setting is No. Setting this option to yes reduces the load on the users computer power supply by allowing the host adapter to start SCSI devices one at a time when you boot your computer. [Note: If the Send Start Unit Command is set to yews for many devices, the boot time will vary depending how long it takes each device to start.]

Include in BIOS Scan

This option allows the user to determine which device the host adapter is to use as a boot device. The Default is Yes. To utilize this option the Host Adapter BIOS and Dynamically Scan for SCSI Devices must be enabled.

Advanced Configuration Settings

This area defines global configuration settings that effect the entire host adapter and the SCSI devices connected to them.

Plug and Play IRQ 9 and DMA 0 Support

(AHA-154XCP only) With Plug and Play technology resources are usually assigned from the lowest to the highest values. However, some computers do not function when IRQ 9 and DMA 0 are used, so the host adapter will not function. The default is Disabled.

Plug and Play SCAM Support

This option determines whether the host adapter automatically assigns SCSI ID's to the SCSI devices with the SCAM protocol. The default is Enabled. The device must be SCAM-compliant, meaning their SCSI ID can be set via SCAM software commands. The user should disable this option if there is a non SCAM compliant device on the SCSI chain.

Host Adapter BIOS

This option enables or disables the host adapter BIOS. The default setting is Enabled. If the user is booting from a SCSI disk drive connected to the host adapter, the BIOS must be enabled. The user should disable the host adapter BIOS if the peripherals on the SCSI bus (for example CD-ROM drives) are all controlled by device drivers and do not need the BIOS.

System Boot (Int 19h) Controlled by Host Adapter

By default this setting is Enabled. On restart and bootup some older systems send a command to system interrupt 19h only, which assumes that the boot device will be an IDE type floppy or fixed hard disk drive. This effectively disables any non IDE drives as boot devices.

The host adapter intercepts the message and routes it to interrupt 13h, the more up to date, non device dependent way to order a system reset. Most of today's PC's call interrupt 13h from 19h for system reset, so enabling or disabling this option will not effect most computers. The user may disable this option if the system uses interrupt 13h for system reset. As long as this option is enabled, the host adapter will detect the system's interrupt and will manage booting.

Dynamically Scan SCSI Bus for BIOS Devices

Enable this option to access and boot from a disk drive from SCSI ID 0 - 6. When this option is disabled the boot drive must be SCSI ID 0. The default is Disabled.

Immediate Return on Seek Command

This option, when enabled, makes it possible for computer benchmark testing programs to return valid results when testing SCSI devices. The default is Enabled.

Support Removable Disks Under BIOS as Fixed Disks

This option controls which removable media drives are supported by the host adapter BIOS. The default setting is Boot Only. The following choices are available:

Boot Only: Only the removable media drive designated as the boot device is treated as a hard disk drive.

All Disk: All removable media drives supported by the BIOS are treated as hard disk drives.

Disabled: No removable media drives are treated as hard disk drives. In this situation, software drivers are needed because the drives are not controlled by the BIOS.

[Note: If a removable media SCSI device is controlled by the host adapter BIOS, do not remove the media while the drive is on or you may lose data! If you want to be able to remove media while the drive is on, install the removable media device driver and set this option to Disable.]

Extended BIOS Translation for DOS Drives > 1 GByte

This option determines whether extended translation is available for SCSI hard disks with capacities greater than 1 GByte. The default setting is Enabled. [Note: If the user decides to change the translation scheme, backup your disk drive first! All data is erased when you change from one translation scheme to another.] Extended BIOS Translation is used only with MS-DOS 5.0 or above. It is not necessary to enable this option if you are using operating such as Novell NetWare, OS/2, Windows NT, or UNIX.

Display Message During BIOS Initialization

This option determines whether the Press for SCSISelect(tm) Utility! message appears on the users screen during system bootup. The default setting is Enabled. If this option is disabled, you can still invoke the SCSISelect utility by pressing after the host adapter BIOS banner appears.

Multiple LUN Support

This option determines whether booting from a SCSI device that has multiple LUNs, or a SCSI device with LUNs is supported. The default setting is Disabled.
[Note: On some host adapters this setting is in the SCSI Device Configuration area. In which case the default setting would be No.]

BIOS Support for More Than 2 Drives

This option determines whether the host adapter BIOS provides support for more than two, and up to eight, hard disk drives. The default setting is Enabled.

If two IDE drives are installed on the computer's hard disk controller, the user can install up to six SCSI drives (supported by the BIOS) on the host adapter, making a total of eight drives.

BIOS Support for Bootable CD-ROM

This option determines whether the host adapter BIOS provides support for booting from a CD-ROM drive. The default is Enabled.

BIOS Support for Int 13 Extensions

This option determines whether the host adapter BIOS supports disks with more than 1024 cylinders. The default is Enabled.

Support for Ultra SCSI Speed

This option determines whether the host adapter supports the fast transfer rates of Ultra SCSI devices. The default setting is Disabled. [Note: On some host adapters this setting is in the SCSI Device Configuration area. In which case the default setting would be No.]




SCSI Terms Explained


There are 2 handshaking modes on the SCSI bus, used for transferring data: ASYNCHRONOUS and SYNCHRONOUS. ASYNCHRONOUS is a classic Req/Ack handshake. SYNCHRONOUS is "sort of" Req/Ack, only it allows you to issue multiple Req's before receiving Ack's. What this means in practice is that SYNCHRONOUS transfers are approx 3 times faster than ASYNCHRONOUS.

SCSI-1 allowed asynchronous transfers at up to 1.5 Mbytes/Sec and synchronous transfers at up to 5.0 Mbytes/Sec.

SCSI-2 had some of the timing margins "shaved" in order that faster handshaking could occur. The result is that asynchronous transfers can run at up to 3.0 bytes/Sec and synchronous transfers at up to 10.0 Mbytes/Sec. The term "FAST" is generally applied to a SCSI device which can do syncrhonous transfers at speeds in excess of 5.0 Mbytes/Sec. This term can only be applied to SCSI-2 devices since SCSI-1 didn't have the timing margins that allow for FAST transfers.

Differential SCSI:

For each signal that needs to be sent across the bus, there exists a pair of wires to carry it. The first in this pair carries the same type of signal the single-ended SCSI carries. The second in this pair, however, carries its logical inversion. The receiver takes the difference of the pair (thus the name differential), which makes it less susceptible to noise and allows for greater cable length.

Single-ended SCSI (normal SCSI):

For each signal that needs to be sent across the bus, there exists a wire to carry it.

Wide SCSI:

SCSI may now transfer data at bus widths of 16 and 32 bits. Commands, status, messages and arbitration are still 8 bits, and the B-Cable has 68 pins for data bits. Cabling was a confusing issue in the closing days of SCSI-2, because the first project of SCSI-3 was the definition of a 16-bit wide P-Cable which supported 16-bit arbitration as well as 16-bit data transfers. Although SCSI-2 does not contain a definition of the P-Cable, it is quite possible that within the year, the P-Cable will be most popular non-SCSI-2 feature on SCSI-2 products. The market responds to what it wants, not the the arbitrary cutoffs of standards committees.

Fast SCSI:

A 10 MHz transfer rate for SCSI came out of a joint effort with the IPI (Intelligent Peripheral Interface) committee in ASC X3T9.3. Fast SCSI achieves 10 Megabytes/second on the A-Cable and with wider data paths of 16-and 32-bits can rise to 20 Megabytes/second and even 40 Megabytes/second. However, by the time the market starts demanding 40 Megabytes/second it is likely that the effort to serialize the physical interface for SCSI-3 will attract high- performance SCSI users to the Fiber Channel.

A word of caution. At this time the fast parameters cannot be met by the Single Ended electrical class, and is only suitable for Differential. One of the goals in SCSI-3 is to identify the improvements needed to achieve 10 MHz operation with Single Ended components.

SCSI Termination:

The Single Ended electrical class depends on very tight termination tolerances, but the passive 132 ohm termination defined in 1986 is mismatched with the cable impedance (typically below 100 ohms). Although not a problem at low speeds when only a few devices are connected, reflections can cause errors when transfer rates increase and/or more devices are added. In SCSI-2, an active terminator has been defined which lowers termination to 110 ohms and is a major boost to system integrity.

Command Queueing:

In SCSI-1, initiators were limited to one command per LUN e.g. a disk drive. Now up to 256 commands can be outstanding to one LUN. The target is allowed to re-sequence the order of command execution to optimize seek motions. Queued commands require Tag messages which follow the Identify.


Asynchronous is faster on short cables, while synchronous is faster on long cables. The reason has to do with the propagation delay of the cable; the turn around time of the silicon; and the interlocked nature of the asynchronous handshake.

  1. We have measured propagation delays from various cables and found an average of 1.7 nanoseconds per foot, which is roughly 5.25 ns per meter.
  2. The turn-around time is the amount of time the SCSI chip takes to change an output in response to an input. If REQ is an input then ACK is an output. Or if ACK is an input then REQ is an output. Typical turn-around time for the 53C90 is 40 nanoseconds.
  3. The asynchronous transfer uses an interlocked handshake where a device cannot do the next thing until it receives positive acknowledgment that the other device received the last thing.
First REQ goes true /* driven by Target */
then ACK is permitted to go true /* driven by Initiator */
then REQ is permitted to go false
then ACK is permitted to go false

Thus we have four "edges" propagating down the cable plus 4 turn-around delays. Asynchronous transfer requires 55 ns setup and no hold time (paragraph in in SCSI-1 or SCSI-2) which gives an upper speed limit around 18 MB/s. A detailed analysis shows that the setup time subtracts out. This is mostly because we are running at one-third the max rate, but also because setup for the next byte can begin anytime after ACK is received true or REQ is received false, depending on who is receiving. You can either take my word for it or draw the waveforms yourself. Thus, the asynchronous transfer reduces to:

(4 * 1.7 * 1) + (4 * 40ns) = 167 ns /* 1 foot cable */
= 6 MB/s
(4 * 5.25 * 6) + (4 * 40ns) = 286 ns /* 6 meter cable */
= 3.5 MB/s
(4 * 5.25 * 25) + (4 * 40ns) = 685 ns /* 25 meter cable */
= 1.5 MB/s

Note: cables longer than 6 meters require external differential transceivers which add delay and degrade the performance even more than indicated here.

Our simulations say that under very best conditions (fast silicon, low temperature, high voltage, zero length cable) we can expect more than 8 MB/s asynchronously. In the lab, I routinely measure 5 MB/s on 8 foot cables. So, if you were writing the data manual for this, how would YOU spec it?

The framers of the SCSI spec threw in synchronous mode to boost the performance on long cables. In synchronous mode, the sending device is permitted to send the next byte without receiving acknowledgment that the receiver actually received the last byte. Kind of a ship and pray method. The acknowledgment is required to come back sometime, but we just don't have to wait for it (handwave the offset stuff and the ending boundary conditions). In this mode any external transceivers add a time shift, but not a delay. So if you negotiate for 5 MB/s, you get 5MB/s regardless how long the cable is and regardless whether you are single-ended or differential. But you can't go faster than 5.5 MB/s, except in SCSI-2.

Synchronous mode does have a hold time (unlike asynch) but again, setup and hold times subtract out. In SCSI-1 synchronous mode, the speed limit comes from the combined ASSERTION PERIOD + NEGATION PERIOD which is 90ns + 90ns = 180ns = 5.5 MB/s. Our 53C90 family doesn't quite hit the max, but we do guarentee 5.0 MB/s. In SCSI-2, anything above 5.0 MB/s is considered to be FAST. Here the maximum transfer rate is explicitly limited to 100 ns or 10MB/s; you don't have to read between the lines to deduce it.

Interesting tid-bit: given a SCSI-2 FAST period of 100 ns and a cable delay of 131 ns on a 25 meter cable, you can actually stack 1.31 bytes in the 8-bit cable. In FAST and WIDE SCSI you can stack 5.24 bytes in this copper FIFO.

Active Termination:

An active terminator actually has one or more voltage regulators to produce the termination voltage, rather than using resistor voltage dividers.

This is a passive terminator:

TERMPWR ------/\/\/\/------+------/\/\/\/----- GND



SCSI signal

Notice that the termination voltage is varies with the voltage on the TERMPWR line. One voltage divider (two resistors) is used for each SCSI signal.

An active terminator looks more like this (supply filter caps omitted):

TERMPWR   -----| in    out |------+------/\/\/\/-------SCSI signal
         |   gnd     |      |
            +-----------+      |
                 |             +------/\/\/\/-------SCSI signal
                  |             |
GND  ---------------+             |
                            +------/\/\/\/-------SCSI signal

Assuming that the TERMPWR voltage doesn't drop below the desired termination voltage (plus the regulator's minimum drop), the SCSI signals will always be terminated to the correct voltage level.

The SCSI specification is available from:

Global Engineering Documents 15 Inverness Way East Englewood Co 80112-5704 (800) 854-7179 SCSI-1: X3.131-1986 SCSI-2: X3.131-199x SCSI-3 X3T9.2/91-010R4 Working Draft

Global Engineering Documentation in Irvine, CA (714)261-1455

SCSI-1: Doc # X3.131-1986 from ANSI, 1430 Broadway, NY, NY 10018

IN-DEPTH EXPLORATION OF SCSI can be obtained from:

Solution Technology Attn: SCSI Publications PO Box 104 Boulder Creek, CA 95006 (408)338-4285, FAX (408)338-4374


ENDL Publishing 14426 Black Walnut Ct. Saratoga, CA 95090 (408)867-6642 FAX (408)867-2115




Sense Codes Described

When the Disk Utility option of SCSISelect is chosen, two options are displayed, Format Disk and Verify Disk. Selection of either option will invoke a bus scan and display all attached devices. Verify Disk is a non-destructive test and is used to verify sector and block information on hard drives. Format Disk is a SCSI command (Format Unit) which is sent to the hard drive by the host adapter. The firmware on the drive implements the format routine programmed by the vendor. This is not a "true" low level factory format command, but is considered a "low level format" for diagnostic and installation issues.
The Adaptec Format Disk command will display the detected size of the hard drive, prompt you that a format will erase any existing data, and prompt for verification of format. The format utility will flash to a red screen with a "Please Wait" notation. There will not be a progress bar during format. The time for a format depends on the drive parameters, but can run as much as 15-20 minutes per GigaByte. Do not reboot your system during format!
The Adaptec Verify Disk command will display the detected size of the hard drive, prompt for the verify function, and display the number of sectors checked, and a progress bar or percentage of total blocks checked. You can use the 'escape' key to exit the utility at any time.
If a drive fails either to format or verify, the cause could be the device, cable, termination, host adapter, host adapter settings, compatibility, or other reason. The format or verify utility will return a error code sequence which can indicate the area of failure. Contact your Adaptec Tech Support or your drive vendor for specific information.

Event code sequence for SCSI Select Disk Verify

  • SCSI ID of the Device
  • SCSI CDB Sent (command descriptor block)
  • e.g., 04 xx xx xx xx xx xx xx xx xx (xx-disregard values) Typical codes: 04 (format), 2F (verify), (03) request sense, 25 (read capacity) Host Adapter Status (usually 00h "no host adapter error" Indicated no error on the host adapter)
  • Target Status
  • Sense key
  • Additional Sense Code
  • Additional Sense Code Qualifier Typical response if drive jumper is not set to spin up the drive at power on:

    SCSI CDB Sent 03 00 00 00 00 00 00 00 00 00
    Host Adapter Status 00h-no host adapter error
    Target Status 02h-check condition
    Sense Key 02h
    Additional Sense Code 04h
    Additional Sense Code Qualifier 02h

  • The sense keys description in the lower-order bits of byte 2 of the sense data returned by the Request Sense command are described in the following table. You can find a more detailed description of the error by checking the additional sense code and the additional sense code qualifier in the next section.

    Sense key Description

    0H No Sense. In the case of a successful command, no specific sense key information needs to be reported for the drive.
    1H Recovered error. The drive completed the last command successfully with some recovery action. When many recovered errors occur during one command, the drive determines which error it will report.
    2H Not ready. The addressed logical unit cannot be accessed. Operator intervention may be required to correct this condition.
    3H Medium error. The command was terminated with a non-recoverable error condition, probably caused by a flaw in the media or an error in the recorded data.
    4H Hardware error. The drive detected a non-recoverable hardware failure while performing the command or during a self-test. This includes, for example, SCSI interface parity errors, controller failures and device failures.
    5H Illegal request. An illegal parameter in the command descriptor block or in the additional parameters supplied as data for some commands (for example, the Format Unit command, the Mode Select command and others). If the drive detects an invalid parameter in the CDB, it terminates the command without altering the media. If the drive detects an invalid parameter in the additional parameters supplied as data, the drive may have already altered the media.
    6H Unit attention. The drive may have been reset. See the Seagate SCSI-2 Interface Manual for more details about the Unit Attention condition.
    BH Aborted command. The drive aborted the command. The initiator may be able to recover by retrying.
    EH Miscompare. The source data did not match the data read from the media.

    Additional sense code and additional sense code qualifier

    The additional sense code and additional sense code qualifiers returned in byte 12 and byte 13, respectively, of the Sense Data Format of the Request Sense command are listed in the following table. Some sense codes and qualifiers are vendor specific and may not be on this table.
    Error code (hex) Description (Bytes 12 and 13):

    00 00 No additional information is supplied.
    01 00 There is no index/sector signal.
    02 00 There is no seek complete signal.
    03 00 A write fault occurred.
    04 00 The drive is not ready and the cause is not reportable.
    04 01 The drive is not ready, but it is in the process of becoming ready.
    04 02 The drive is not ready; it is waiting for the initializing command.
    04 03 The drive is not ready; human intervention is required.
    04 04 The drive is not ready; the format routine is in process.
    05 00 The drive does not respond when it is selected.
    06 00 Track 0 was not found.
    07 00 More than one drive is selected at a time.
    08 00 There was a drive communication failure.
    08 01 A drive communication time-out occurred.
    08 02 A drive communication parity error occurred.
    09 00 A track following error occurred.
    0A 00 An error log overflow occurred.
    0C 01 A write error occurred, but the error was recovered using auto-reallocation.
    0C 02 A write error occurred. Auto-reallocation was attempted, but it failed.
    10 00 An ID CRC or ECC error occurred.
    11 00 An unrecovered read error occurred.
    11 01 The read retries were exhausted.
    11 02 The error was too long to correct.
    11 03 There were multiple read errors.
    11 04 A read error occurred. Auto-reallocation was attempted, but it failed.
    12 00 The address mark was not found in the ID field.
    13 00 The address mark was not found in the data field.
    14 00 No record was found.
    14 01 No record was found.
    15 00 A seek positioning error occurred.
    15 01 A mechanical positioning error occurred.
    15 02 A positioning error was detected by reading the media.
    16 00 A data synchronization mark error occurred.
    17 00 The data was recovered without applying error correction or retrying.
    17 01 The data was recovered with retries.
    17 02 The data was recovered with positive head offset.
    17 03 The data was recovered with negative head offset.
    17 05 The data was recovered using the previous sector ID.
    17 06 The data was recovered without ECC. The drive uses data auto-reallocation.
    18 00 The data was recovered with ECC.
    18 01 The data was recovered with ECC and retries.
    18 02 The data was recovered with ECC, retries, and auto-reallocation.
    19 00 There is an error in the defect list.
    19 01 The defect list is not available.
    19 02 There is an error in the primary defect list.
    19 03 There is an error in the grown defect list.
    1A 00 A parameter overrun occurred.
    1B 00 A synchronous transfer error occurred.
    1C 00 The defect list could not be found.
    1C 01 The primary defect list could not be found.
    1C 02 The grown defect list could not be found.
    1D 00 During a verify operation, a compare error occurred: the source data did not match the data read from the media.
    1E 00 An ID error was recovered.
    20 00 The drive received an invalid command operation code.
    21 00 The logical block address was not within the acceptable range.
    22 00 The drive received a CDB that contains an invalid bit.
    (This error code applies to direct-access devices.)
    24 00 The drive received a CDB that contains an invalid bit.
    (This error code applies to all SCSI devices.)
    25 00 The drive received a CDB that contains an invalid LUN.
    26 00 The drive received a CDB that contains an invalid field.
    26 01 The drive received a CDB containing a parameter that is not supported.
    26 02 The drive received a CDB containing an invalid parameter.
    26 03 The drive received a CDB containing a threshold parameter that is not supported.
    29 00 A power-on reset or a bus device reset occurred.
    2A 00 Some parameters were changed by another initiator.
    2A 01 The Mode Select parameters were changed by another initiator.
    2B 00 The microcode was downloaded.
    2F 00 The tagged commands were cleared by another initiator.
    30 01 The media cannot be read because the format is not recognized.
    30 02 The media cannot be read because the format is incompatible with certain parameters.
    31 00 The media format is corrupted.
    31 01 The format command failed.
    32 00 There are no spare defect locations available.
    32 01 An error occurred when the defect list was being updated.
    37 00 A rounded parameter caused an error.
    3D 00 The identify message contains invalid bits.
    3F 00 The target operation command was changed.
    3F 01 The microcode was changed.
    3F 02 The drive was operating as a SCSI drive and is now operating as a SCSI-2 drive, or vice versa.
    3F 03 The inquiry data was changed.
    40 00 The RAM failed.
    40 8x A correctable ECC error occurred; x equals the length of the error.
    40 90 A configuration error occurred.
    40 A0 The self-test routine discovered an error in a ROM.
    40 A1 The self-test routine discovered an error in the processor RAM.
    40 A2 The self-test routine discovered an error in the buffer RAM.
    40 A3 The self-test routine discovered a SCSI protocol error.
    40 A4 The self-test routine discovered a DMA error.
    40 A5 The self-test routine discovered an error in the disc sequencer.
    40 A6 The self-test routine discovered an error in the disc sequencer RAM.
    40 A7 A self-test error occurred.
    40 A8 The flash memory cannot be read or written.
    40 A9 The flash memory directory cannot be read, or it is corrupted.
    40 AA The flash memory contains an incompatible version number.
    40 AB The flash memory contains an incompatible revision number.
    40 AC A flash memory checksum error occurred.
    40 AD The flash memory contains invalid parameters.
    40 AE The flash memory is incompatible with the HDA and the circuit board. The flash memory must be reconfigured.
    40 B0 The servo command timed out.
    40 B1 The servo command failed.
    40 B2 The servo command was rejected.
    40 B3 The servo interface does not work.
    40 B4 The servo either failed to lock on track during spinup or has wandered off track.
    40 B5 An internal servo error occurred.
    40 B6 During spinup, a servo error occurred.
    40 B7 The servo pattern is inconsistent.
    40 B8 A seek recovery error occurred.
    40 B9 The actuator did not achieve high-speed calibration.
    40 C0 The defect list is full.
    40 C1 A failure occurred while the grown defect list was being written.
    40 C2 The write life-cycle of the flash memory has been exceeded.
    40 C3 There was an attempt to add an illegal entry to the grown defect list.
    40 C4 There was an attempt to add a duplicate entry to the grown defect list.
    41 00 A data path diagnostic failed.
    42 00 A power-on or self-test failure occurred.
    43 00 A message reject error occurred.
    44 00 An internal controller error occurred.
    45 00 An error occurred during a selection or a reselection.
    47 00 A SCSI interface bus parity error occurred.
    48 00 The initiator has detected an error.
    49 00 The initiator received an invalid message from the drive.
    4C 00 The drive failed to self-configure.
    4E 00 The drive attempted to perform overlapped commands.
    5B 00 There was a log exception.
    5B 01 A threshold condition was met.
    5B 02 The log counter has reached its maximum value.
    5B 03 All the log list codes have been used.
    5C 00 There was a change in the RPL status. The drive lost synchronization.

    Number of devices
    Up to 15 devices total

    Bus System Interface Type

    PCI local bus
    External Connectors
    68-pin High-Density
    Data Transfer Rate
    40 MByte/sec
    Package Contents
    AHA-2940 UW PCI-to-Wide UltraSCSI host adapter board Adaptec 7800 Family Manager Set software drivers for Windows NT, Windows 95, OS/2 2.x and 3.x, Netware 3.x and 4.x, SCO Unix 3.2.x and Unixware 1.x and 2.x Adaptec EZ-SCSI software for Windows NT, Windows 95, Windows for Workgroups, and DOS Includes applications such as: SCSI Tape Backup™ (Backup Basics), QuickScan, CD Player, Photo CD Viewer (Magic Lantern™),Advanced Power Management, SCSI Interrogator™, SCSI Disk Partitioner, SCSITutor™, SCSIBench Provides device support for hard disks, removable disks, MO, CD-ROM,CD-Recordable, Photo CD and tape drives and scanners One 3-position, 68-pin UltraSCSI internal ribbon cable One 3-position, 50-pin UltraSCSI internal ribbon cableComplete user documentationFive-year warranty card
    5 year

    Supported Protocols

    WIDE UltraSCSI

    Advanced SCSI Features

    multi-threaded I/O,
    tagged queuing,
    synchronous and asynchronous data transfer

    Electrical Drivers

    Single-ended, active, programmable via SCSISelect configuration utility

    Board Dimensions

    6.87" x 3.87" (17.0 cm x 9.5 cm)

    Operating Characteristics

    32 F to 131 F (0 C to 55 C)10% to 90% Relative Humidity, non condensing

    Storage Characteristics

    -67 F to 185 F (-55 C to 85 C)

    MTBF (mean time between failures, Bellcore)

    494,641 hours