# EISA

EISA=Extended Industry Standard Architecture.
Developed by Compaq, AST, Zenith, Tandy...

    +---------------------------------------------+
    |            (component side)                 |
    |                                             |
    |___________ ISA-16bit __       ISA-8bit    __|
                |||||||||||  |||||||||||||||||||  A1(front)/B1(back)
                 | | | | |    | | | | | | | | |  EISA: E1(front)/F1(back)
                       C1/D1
                      G1/H1

    A,C,E,G=Component Side
    A,B,F,H=Sold Side

(at the computer)

62+38 PIN EDGE CONNECTOR at the computer.

Pin | Name | Description
--- | --- | ---
E1 | CMD# | Command Phase
E2 | START# | Start Phase
E3 | EXRDY | EISA Ready
E4 | EX32# | EISA Slave Size 32
E5 | GND | Ground
E6 | KEY | Access Key
E7 | EX16# | EISA Slave Size 16
E8 | SLBURST# | Slave Burst
E9 | MSBURST# | Master Burst
E10 | W/R# | Write/Read
E11 | GND | Ground
E12 | RES | Reserved
E13 | RES | Reserved
E14 | RES | Reserved
E15 | GND | Ground
E16 | KEY | Access Key
E17 | BE1# | Byte Enable 1
E18 | LA31# | Latchable Addressline 31
E19 | GND | Ground
E20 | LA30# | Latchable Addressline 30
E21 | LA28# | Latchable Addressline 28
E22 | LA27# | Latchable Addressline 27
E23 | LA25# | Latchable Addressline 25
E24 | GND | Ground
E25 | KEY | Access Key
E26 | LA15 | Latchable Addressline 15
E27 | LA13 | Latchable Addressline 13
E28 | LA12 | Latchable Addressline 12
E29 | LA11 | Latchable Addressline 11
E30 | GND | Ground
E31 | LA9 | Latchable Addressline 9
F1 | GND | Ground
F2 | +5V | +5 VDC
F3 | +5V | +5 VDC
F4 | --- |
F5 | --- |
F6 | KEY | Access Key
F7 | --- |
F8 | --- |
F9 | +12V | +12 VDC
F10 | M/IO# | Memory/Input-Output
F11 | LOCK# | Lock bus
F12 | RES | Reserved
F13 | GND | Ground
F14 | RES | Reserved
F15 | BE3# | Byte Enable 3
F16 | KEY | Access Key
F17 | BE2# | Byte Enable 2
F18 | BE0# | Byte Enable 0
F19 | GND | Ground
F20 | +5V | +5 VDC
F21 | LA29# | Latchable Addressline 29
F22 | GND | Ground
F23 | LA26# | Latchable Addressline 26
F24 | LA24# | Latchable Addressline 24
F25 | KEY | Access Key
F26 | LA16 | Latchable Addressline 16
F27 | LA14 | Latchable Addressline 14
F28 | +5V | +5 VDC
F29 | +5V | +5 VDC
F30 | GND | Ground
F31 | LA10 | Latchable Addressline 10
G1 | LA7 | Latchable Addressline 7
G2 | GND | Ground
G3 | LA4 | Latchable Addressline 4
G4 | LA3 | Latchable Addressline 3
G5 | GND | Ground
G6 | KEY | Access Key
G7 | D17 | Data 17
G8 | D19 | Data 19
G9 | D20 | Data 20
G10 | D22 | Data 22
G11 | GND | Ground
G12 | D25 | Data 25
G13 | D26 | Data 26
G14 | D28 | Data 28
G15 | KEY | Access Key
G16 | GND | Ground
G17 | D30 | Data 30
G18 | D31 | Data 31
G19 | MREQx | Master Request
H1 | LA8 | Latchable Addressline 8
H2 | LA6 | Latchable Addressline 6
H3 | LA5 | Latchable Addressline 5
H4 | +5V | +5 VDC
H5 | LA2 | Latchable Addressline 2
H6 | KEY | Access Key
H7 | D16 | Data 16
H8 | D18 | Data 18
H9 | GND | Ground
H10 | D21 | Data 21
H11 | D23 | Data 23
H12 | D24 | Data 24
H13 | GND | Ground
H14 | D27 | Data 27
H15 | KEY | Access Key
H16 | D29 | Data 29
H17 | +5V | +5 VDC
H18 | +5V | +5 VDC
H19 | MAKx | Master Acknowledge

Contributor: Joakim Ögren, Mark Sokos

Sources:
Mark Sokos EISA page
"EISA System Architecture, 2nd Edition" by Tom Shanley and Don Anderson, ISBN 0-201-40995-X
comp.sys.ibm.pc.hardware.* FAQ Part 4 - maintained by Ralph Valentino

Copyright © The Hardware Book Team 1996-2001.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2001-06-08