Adaptec's AHA-3940 and AHA-3940W MultiChannel host adapters are designed for use in computers that have 5-volt Peripheral Component Interconnect (PCI) interface slots. Each AHA-3940 and AHA-3940W MultiChannel host adapter has two SCSI channels, each of which functions as an independent host adapter. Channel A has both an internal and an external SCSI connector; Channel B has only an internal SCSI connector. With the AHA-3940, you can connect up to seven 8-bit SCSI devices per channel. With the AHA-3940W, you can connect up to fifteen 16-bit (Wide) SCSI devices per channel.
Small Image of AHA-3940
DownloadsDocumentationTechnical Specifications

Note: Only drivers that are not included or embedded within a supported operating system are listed below. To see a complete list of supported operating systems see the Product Specifications

Select your operating system or software below

Bios Updates and Other Downloadable Files

Bios Updates and Other Downloads




Microsoft DOS
Microsoft Windows 2000
Microsoft Windows 3.1x
Microsoft Windows 7
Microsoft Windows 95
Microsoft Windows 98
Microsoft Windows Millennium
Microsoft Windows NT
Microsoft Windows Server 2008
Microsoft Windows Vista

Novell NetWare

Novell NetWare Downloads


SCO Unix
SCO UnixWare

Hardware Installation
how to install your adaptec pci card (html 74 kb)
pci architecture overview (html 74 kb)
Installing Drivers or Software
cd install netware 401 (html 69 kb)
7800 netware instructions (html 81 kb)
7800 family manager set 98 contents (html 68 kb)
installing 98 driver (html 70 kb)
windows 98 issues (html 70 kb)
7800 miniport issues in 95 (html 70 kb)
installing windows nt driver (html 82 kb)
7800 supported adapters (html 72 kb)
aic7870.dsk options (html 76 kb)
7800 netware contents (html 70 kb)
7800 issues for netware (html 71 kb)
7800 netware notes (html 70 kb)
miniport options (html 70 kb)
2940 winnt 3.x (html 70 kb)
7800 diskette contents (html 68 kb)
os/2 driver installation (html 68 kb)
unix driver disk conversion (html 69 kb)
loading adaptec dsk drivers (html 71 kb)
netware 3.12 cd install (html 68 kb)
7800 unix driver instructions (html 75 kb)
os/2 driver notes (html 77 kb)
7800 os/2 diskette (html 69 kb)
7800 os/2 issues (html 68 kb)
sco unix driver installation (html 75 kb)
7800 fms support list (html 72 kb)
3940 pci bridge list (html 76 kb)
Product Documentation
Install Guide for the AHA-3940/3940W (PDF 148 KB)
User Guide for the AHA-3940/3940W (PDF 577 KB)
Use Your Product
scsi<i>select</i> user's guide (html 83 kb)
scsi terms explained (html 77 kb)
sense codes described (html 96 kb)
Number of devices
Up to 7 devices under DOS 5.0 and above

Bus System Interface Type

PCI Local Bus
Data Transfer Rate
20 Mbytes/sec (10 Mbytes/sec per channel) Two channel Fast SCSI-2
Package Contents
AHA-3940 or AHA-3940W PCI MultiChannel host adapterSCSISelect configuration softwareAdaptec EZ-SCSI software for DOS and WindowsAdaptec 7800 Family Manager Set softwareDevice support for hard disk, removable, MO, CD-ROM, Photo CD, tape, DAT, scanner, and Floptical® drivesAdaptec CI/O Single Server software for NetWare network serversSytron's Proserve CX Lite™ - tape backup software for NetWareComplete hardware and software documentationInternal SCSI ribbon cables (external cable not included)
5 year

Supported Protocols

8-bit Fast SCSI-2

Advanced SCSI Features

  • Advanced SCSI Programming Interface (ASPI) compliant
  • Multitasking operating system support (through scatter/gather, disconnect/reconnect, tagged command queuing support)
  • Independent negotiation of high-speed data transfers (Fast, Wide, and synchronous) with each device
  • Support for 255 simultaneous active SCSI commands per channel

SCSI channels

Two fully independent PCI SCSI channels bridged to system PCI bus

Electrical drivers

Single-ended and active. Each channel is programmable via SCSISelect

Board Dimensions

6.875" x 4.0"

Power Consumption

5 V +/- 5% at 2.0 amps maximum

Operating Characteristics

32° F to 131° F (0° C to 55° C)10% to 95% Relative Humidity, non condensing

Storage Characteristics

-67° F to 185° F (-65° C to 105° C)