Standard PC Storage Devices and I/O Connector Pinouts.
This information may be shared freely but not sold for profit!
This data is provided in a text format to allow greater ease
of formatting into existing technical documents.
This information compiled and provided by
Dick Perron dperr@randomc.com
Standard PC storage devices and
I/O connector pinouts.
FDD 34 pin connector
IDE 40 pin and 44 pin connector
RLL/MFM disk drive connectors
ESDI disk drive connectors
ISA/EISA I/O connectors
VESA local bus connector
PCI local bus I/O pinouts
30 pin SIMM pinouts
72 pin SIMM pinouts
FLOPPY DISK 34 PIN CABLE PINOUT
2--LDENSEL# 4--Microfloppy 6--EDENSEL 8--INDX# 10-MTEN1#
12-DRSEL0# 14-DRSEL1# 16-DTEN0# 18-DIR# 20-STP#
22-WRDATA# 24-WREN# 26-TRK0# 28-WRPRDT# 30-RDDATA#
32-HDSEL1# 34-DSKCHG#
All ODD numbered pins are grounded.
Note!! Pin 34 is the disk change interrupt line. If the cable is "cocked" on
the connector you may not detect the change when u insert a new disk in the drive.
A DOS DIR command will always show the contents of the first disk installed.
34 PIN IDC EDGE SOCKET CONNECTOR 34 PIN DIL SOCKET CONNECTOR
34 2 1 33
----------------- ooooooooooooooooo
----------------- ooooooooooooooooo
33 1 2 34
Edge connectors and IDC connectors are mounted on opposite sides of the ribbon cable in order
to orient pin #1 correctly and this is why you have to twist the cable between the 5.25" drive
and the 3.5" drive. You will see this on "universal" FDD cable sets.
3.5" IDE/EIDE DISK DRIVE CABLE 40 PIN AND 2.5" 44 PIN MALE DUAL INLINE COMNECTOR
43 39 1 K C A
o o o o o o o o o o o o o o o o o o o E o o
o o o o o o o o o o o o o o o o o o o Y o o
44 40 2 D B
A--MFG USE B--MFG USE C--MFG USE D--MFG USE
1--Reset 2--GND 3--HD7 4--HD8 5--HD6
6--HD9 7--HD5 8--HD10 9--HD4 10-HD11
11-HD3 12-HD12 13-HD2 14-HD13 15-HD1
16-HD14 17-HD0 18-HD15 19-GND 20-KEY
21-RESVD 22-GND 23-IOW# 24-GND 25-IOR#
26-GND 27-IORDY# 28-ALE 29-RESVD 30-GND
31-IRQ14 32-IO16# 33-HA1 34-RESVD# 35-HA0
36-HA2 37-CS0# 38-CS1# 39-DRAC# 40-GND
41-+5V Logic 42-+5V Motor 43-Gnd 44-TYPE ((0=ATA)
Note!! Pins 37 and 38 are used for the cable select option.
If the CS option is enabled the drive # will be determined
by whether the drive is attached to the first or second
connector on the cable. A special cable is needed to utilize
the cable select option.
If the cable does not have pin 20 keyed then pin #1 on the cable is determined
by the RED stripe on the edge of the cable.
The control signals are the same for the 40 pin and 44 pin cable.
The 44 pin socket is a 50 pin connector with two pins removed to clear the wall
of the connector socket. Pins A-D at the drive end are reserved for MFG use and
are NOT connected to the host through the cable.
RLL/MFM HARD DISK IDC-34 Male and IDC-20 Male
RLL/MFM IDC-34 CONTROL CABLE
pin Signal pin Signal
1 GND 2 Head Sel 8
3 GND 4 Head Sel 4
5 GND 6 Write Gate
7 GND 8 Seek Complete
9 GND 10 Track 0
11 GND 12 Write Fault
13 GND 14 Head Sel 1
15 GND 16 (reserved)
17 GND 18 Head Sel 2
19 GND 20 Index
21 GND 22 Ready
23 GND 24 Step
25 GND 26 Drive Sel 1
27 GND 28 Drive Sel 2
29 GND 30 Drive Sel 3
31 GND 32 Drive Sel 4
33 GND 34 Direction In
RLL/MFM IDC-20 DATA CABLE
pin Signal pin Signal
1 Drive Selected 2 GND
3 (reserved) 4 GND
5 (reserved) 6 GND
7 (reserved) 8 GND
9 (reserved) 10 (reserved)
11 GND 12 GND
13 Write Data+ 14 Write Data-
15 GND 16 GND
17 Read Data+ 18 NRZ Read Data-
19 GND 20 GND
ESDI 34 PIN CONTROL CABLE AND 20 PIN DATA CABLE PINOUTS
ESDI IDC-34 CONTROL CABLE
pin Signal pin Signal
1 GND 2 Head Sel 3
3 GND 4 Head Sel 2
5 GND 6 Write Gate
7 GND 8 Config/Stat Data
9 GND 10 Transfer Ack
11 GND 12 Attn
13 GND 14 Head Sel 0
15 GND 16 Sect/Add MK Found
17 GND 18 Head Sel 1
19 GND 20 Index
21 GND 22 Ready
23 GND 24 Trans Req
25 GND 26 Drive Sel 1
27 GND 28 Drive Sel 2
29 GND 30 Drive Sel 3
31 GND 32 Read Gate
33 GND 34 Command Data
ESDI IDC-20 DATA CABLE
pin Signal pin Signal
1 Drive Selected 2 Sect/Add MK Found
3 Seek Complete 4 Addr Mark Enable
5 (reserved) 6 GND
7 Write Clk+ 8 Write Clk-
9 Cartridge Chng 10 Read Ref Clk+
11 Read Ref Clk- 12 GND
13 NRZ Write Data+ 14 NRZ Write Data-
15 GND 16 GND
17 NRZ Read Data+ 18 NRZ Read Data-
19 GND 20 GND
SCSI CONNECTOR PINOUTS (Single Ended) IDC-50 MALE
pin Signal pin Signal pin Signal pin Signal
01 GND 02 -DB0 27 GND |28 GND
03 GND 04 -DB1 29 GND |30 GND
05 GND 06 -DB2 31 GND |32 -ATN
07 GND 08 -DB3 33 GND |34 GND
09 GND 10 -DB4 35 GND |36 -BSY
11 GND 12 -DB5 37 GND |38 -ACK
13 GND 14 -DB6 39 GND |40 -RST
15 GND 16 -DB7 41 GND |42 -MSG
17 GND 18 -DBP 43 GND |44 -SEL
19 GND 20 GND 45 GND |46 -C/D
21 GND 22 GND 47 GND |48 -REQ
23 GND 24 GND 49 GND |50 -I/O
25 (open) 26 TERMPW
SCSI CONNECTOR PINOUTS (Differential) IDC-50 MALE
pin Signal pin Signal pin Signal pin Signal
01 (open) 02 GND 27 GND 28 GND
03 +DB0 04 -DB0 29 +ATN 30 -ATN
05 +DB1 06 -DB1 31 GND 32 GND
07 +DB2 08 -DB2 33 +BSY 34 -BSY
09 +DB3 10 -DB3 35 +ACK 36 -ACK
11 +DB4 12 -DB4 37 +RST 38 -RST
13 +DB5 14 -DB5 39 +MSG 40 -MSG
15 +DB6 16 -DB6 41 +SEL 42 -SEL
17 +DB7 18 -DB7 43 +C/D 44 -C/D
19 +DBP 20 -DBP 45 +REQ 46 -REQ
21 DIFFSENS 22 GND 47 +I/O 48 -I/O
23 GND 24 GND 49 GND 50 GND
25 TERMPWR 26 TERMPWR
Macintosh SCSI Connector Pinouts (Single Ended) DB-25S Female
pin Signal pin Signal pin Signal pin Signal
01 -REQ 08 -DB0 14 GND 20 -DBP
02 -MSG 09 GND 15 -C/D 21 -DB1
03 -I/O 10 -DB3 16 GND 22 -DB2
04 -RST 11 -DB5 17 -ATN 23 -DB4
05 -ACK 12 -DB6 18 GND 24 GND
06 -BSY 13 -DB7 19 -SEL 25 NC (TERMPWR)
07 GND
ISA/EISA I/O CONNECTOR PIN ASSIGNMENTS
ISA Bus Connector EISA Bus Connector
----------------- ------------------
Etch Side Component Side Etch Side Component Side
pin Signal pin Signal pin Signal pin Signal
B1 GND A1 CHCHK# F1 GND E1 CMD#
B2 Reset DRV A2 SD7 F2 +5V E2 START#
B3 +5V A3 SD6 F3 +5V E3 EXRDY
B4 IRQ9 A4 SD5 F4 --- E4 EX32#
B5 -5V A5 SD4 F5 --- E5 GND
B6 DRQ2 A6 SD3 F6 ACCESS KEY E6 ACCESS KEY
B7 -12V A7 SD2 F7 --- E7 EX16#
B8 NOWS# A8 SD1 F8 --- E8 SLBURST#
B9 +12V A9 SD0 F9 +12V E9 MSBURST#
B10 GND A10 CHRDY F10 M/IO# E10 W/R#
B11 SMWTC# A11 AEN F11 LOCK# E11 GND
B12 SMRDC# A12 SA19 F12 (reserved) E12 (reserved)
B13 IOWC# A13 SA18 F13 GND E13 (reserved)
B14 IORC# A14 SA17 F14 (reserved) E14 (reserved)
B15 DACK3# A15 SA16 F15 BE3# E15 GND
B16 DRQ3 A16 SA15 F16 ACCESS KEY E16 ACCESS KEY
B17 DACK1# A17 SA14 F17 BE2# E17 BE1#
B18 DRQ1 A18 SA13 F18 BE0# E18 LA31#
B19 REFRESH# A19 SA12 F19 GND E19 GND
B20 BCLK A20 SA11 F20 +5V E20 LA30#
B21 IRQ7 A21 SA10 F21 LA29# E21 LA28#
B22 IRQ6 A22 SA9 F22 GND E22 LA27#
B23 IRQ5 A23 SA8 F23 LA26# E23 LA25#
B24 IRQ4 A24 SA7 F24 LA24# E24 GND
B25 IRQ3 A25 SA6 F25 ACCESS KEY E25 ACCESS KEY
B26 DACK2# A26 SA5 F26 LA16 E26 LA15
B27 T/C A27 SA4 F27 LA14 E27 LA13
B28 BALE A28 SA3 F28 +5V E28 LA12
B29 +5V A29 SA2 F29 +5V E29 LA11
B30 OSC A30 SA1 F30 GND E30 GND
B31 GND A31 SA0 F31 LA10 E31 LA9
H1 LA8 G1 LA7
D1 M16# C1 SBHE# H2 LA6 G2 GND
D2 IO16# C2 LA23 H3 LA5 G3 LA4
D3 IRQ10 C3 LA22 H4 +5V G4 LA3
D4 IRQ11 C4 LA21 H5 LA2 G5 GND
D5 IRQ12 C5 LA20 H6 ACCESS KEY G6 ACCESS KEY
D6 IRQ15 C6 LA19 H7 D16 G7 D17
D7 IRQ14 C7 LA18 H8 D18 G8 D19
D8 DACK0# C8 LA17 H9 GND G9 D20
D9 DRQ0 C9 MRDC# H10 D21 G10 D22
D10 DACK5# C10 MWTC# H11 D23 G11 GND
D11 DRQ5 C11 SD8 H12 D24 G12 D25
D12 DACK6# C12 SD9 H13 GND G13 D26
D13 DRQ6 C13 SD10 H14 D27 G14 D28
D14 DACK7# C14 SD11 H15 ACCESS KEY G15 ACCESS KEY
D15 DRQ7 C15 SD12 H16 D29 G16 GND
D16 +5V C16 SD13 H17 +5V G17 D30
D17 MASTER16# C17 SD14 H18 +5V G18 D31
D18 GND C18 SD15 H19 MAKx G19 MREQx
VESA LOCAL BUS (VLB) I/O CONNECTOR
Etch side Component Side Etch Side Component Side
pin Signal pin Signal pin Signal pin Signal
B1 Dat00 A1 Dat01 B30 Adr17 A30 Adr16
B2 Dat02 A2 Dat03 B31 Adr15 A31 Adr14
B3 Dat04 A3 GND B32 Vcc A32 Adr12
B4 Dat06 A4 Dat05 B33 Adr13 A33 Adr10
B5 Dat08 A5 Dat07 B34 Adr11 A34 Adr08
B6 GND A6 Dat09 B35 Adr09 A35 GND
B7 Dat10 A7 Dat11 B36 Adr07 A36 Adr06
B8 Dat12 A8 Dat13 B37 Adr05 A37 Adr04
B9 Vcc A9 Dat15 B38 GND A38 WBACK#
B10 Dat14 A10 GND B39 Adr03 A39 BEO#
B11 Dat16 A11 Dat17 B40 Adr02 A40 Vcc
B12 Dat18 A12 Vcc B41 n/c A41 BE1#
B13 Dat20 A13 Dat19 B42 RESET# A42 BE2#
B14 GND A14 Dat21 B43 DC# A43 GND
B15 Dat22 A15 Dat23 B44 M/ID# A44 BE3#
B16 Dat24 A16 Dat25 B45 W/R# A45 ADS#
B17 Dat26 A17 GND B46 A46
B18 Dat28 A18 Dat27 B47 A47
B19 Dat30 A19 Dat29 B48 RDYRTN# A48 LRDY#
B20 Vcc A20 Dat31 B49 GND A49 LDEV<x>#
B21 Adr31 A21 Adr30 B50 IRQ9 A50 LREQ<x>#
B22 GND A22 Adr28 B51 BRDY# A51 GND
B23 Adr29 A23 Adr26 B52 BLAST# A52 LGNT<x>#
B24 Adr27 A24 GND B53 ID0 A53 Vcc
B25 Adr25 A25 Adr24 B54 ID1 A54 ID2
B26 Adr23 A26 Adr22 B55 GND A55 ID3
B27 Adr21 A27 Vcc B56 LCLK A56 ID4
B28 Adr19 A28 Adr20 B57 Vcc A57 LKEN#
B29 GND A29 Adr18 B58 LBS16# A58 LEAD5#
PCI LOCAL BUS I/O CONNECTOR
PCI Cards Universal/3.3V/5V and 32/64 bit
pin Signal pin Signal pin Signal pin Signal
B1 -12V A1 TRST# B48 AD[10] A48 Ground
B2 TCK A2 +12V B49 Ground A49 AD[09]
B3 Ground A3 TMS B50 (KEYWAY2) A50 (KEYWAY2)
B4 TDO A4 TDI B51 (KEYWAY2) A51 (KEYWAY2)
B5 +5V A5 +5V B52 AD[08] A52 C/BE[0]#
B6 +5V A6 INTA# B53 AD[07] A53 +3.3V
B7 INTB# A7 INTC# B54 +3.3V A54 AD[06]
B8 INTD# A8 +5V B55 AD[05] A55 AD[04]
B9 PRSNT1# A9 reserved B56 AD[03] A56 Ground
B10 reserved A10 +Vi/o B57 Ground A57 AD[02]
B11 PRSNT2# A11 reserved B58 AD[01] A58 AD[00]
B12 (KEYWAY1) A12 (KEYWAY1) B59 Vi/o A59 +Vi/o
B13 (KEYWAY1) A13 (KEYWAY1) B60 ACK64# A60 REQ64#
B14 reserved A14 reserved B61 +5V A61 +5V
B15 Ground A15 RST# B62 +5V A62 +5V
B16 CLK A16 Vi/o B63 reserved A63 Ground
B17 Ground A17 VNT# B64 Ground A64 C/BE[7]#
B18 REQ# A18 Ground B65 C/BE[6]# A65 C/BE[5]#
B19 +Vi/o A19 reserved B66 C/BE[4]# A66 +Vi/o
B20 AD[31] A20 AD[30] B67 Ground A67 PAR64
B21 AD[29] A21 +3.3V B68 AD[63] A68 AD[62]
B22 Ground A22 AD[28] B69 AD[61] A69 Ground
B23 AD[27] A23 AD[26] B70 +Vi/o A70 AD[60]
B24 AD[25] A24 Ground B71 AD[59] A71 AD[58]
B25 +3.3V A25 AD[24] B72 AD[57] A72 Ground
B26 C/BE[3]# A26 IDSEL B73 Ground A73 AD[56]
B27 AD[23] A27 +3.3V B74 AD[55] A74 AD[54]
B28 Ground A28 AD[22] B75 AD[53] A75 +Vi/o
B29 AD[21] A29 AD[20] B76 Ground A76 AD[52]
B30 AD[19] A30 Ground B77 AD[51] A77 AD[50]
B31 +3.3V A31 AD[18] B78 AD[49] A78 Ground
B32 AD[17] A32 AD[16] B79 +Vi/o A79 AD[48]
B33 C/BE[2]# A33 +3.3V B80 AD[47] A80 AD[46]
B34 Ground A34 FRAME# B81 AD{45] A81 Ground
B35 IRDY# A35 Ground B82 Ground A82 AD[44]
B36 +3.3V A36 TRDY# B83 AD[43] A83 AD[42]
B37 DEVSEL# A37 Ground B84 AD[41] A84 +Vi/o
B38 Ground A38 STOP# B85 Ground A85 AD[40]
B39 LOCK# A39 +3.3V B86 AD[39] A86 AD[38]
B40 PERR# A40 SDONE B87 AD[37] A87 Ground
B41 +3.3V A41 SBO# B88 +Vi/o A88 AD[36]
B42 SERR# A42 Ground B89 AD[35] A89 AD[34]
B43 +3.3V A43 PAR B90 AD[33] A90 Ground
B44 C/BE[1]# A44 AD[15] B91 Ground A91 AD[32]
B45 AD[14] A45 +3.3V B92 reserved A92 reserved
B46 Ground A46 AD[13] B93 reserved A93 Ground
B47 AD[12] A47 AD11] B94 Ground A94 reserved
Note!! Pins 63-94 exist on 64 bit PCI implementation only.
KEYWAY1 exists on Universal and 3.3V boards, they are Ground on 5V boards.
KEYWAY2 exists on Universal and 5V boards, they are Ground on 3.3V boards.
+Vi/o is 3.3V on 3.3V boards, 5V on 5V boards, and define signal rails on
the Universal board.
30 PIN SIMM CONNECTOR
30 pin Fast Page Mode SIMM 256kx8 256kx9 1Mx8 1Mx9 4Mx8 4Mx9
pin Signal pin Signal pin Signal pin Signal
1 Vcc 9 Gnd 17 A8 25 DQ7
2 -CAS 10 DQ2 18 A9 26 QP
3 DQ0 11 A4 19 A10 27 -RAS
4 A0 12 A5 20 DQ5 28 -CASP
5 A1 13 DQ3 21 -WE 29 DP
6 DQ1 14 A6 22 Gnd 30 Vcc
7 A2 15 A7 23 DQ6
8 A3 16 DQ4 24 N/C
Note!! QP, CASP and DP are N/C on all x8 bit modules
a9 is a N/C on 256k modules
a10 is a N/C on 256k and 1M modules
Although there are 30 tabs on each side of the SIMM PCB
there are only 30 signal connectors on the SIMM socket and
each tab is a redundant connection.
72 PIN SIMM CONNECTOR
72 pin Fast Page Mode SIMM 256k/512k/1M/2M/4M/8M x 32/36 bit
pin Signal pin Signal pin Signal pin Signal
1 Gnd 19 A10 37 MP1 55 DQ11
2 DQ0 20 DQ4 38 MP3 56 DQ27
3 DQ16 21 DQ20 39 Gnd 57 DQ12
4 DQ1 22 DQ5 40 -CAS0 58 DQ28
5 DQ17 23 DQ21 41 -CAS2 59 Vcc
6 DQ2 24 DQ6 42 -CAS3 60 DQ29
7 DQ18 25 DQ22 43 -CAS1 61 DQ13
8 DQ3 26 DQ7 44 -RAS0 62 DQ30
9 DQ19 27 DQ23 45 -RAS1 63 DQ14
10 Vcc 28 A7 46 N/C 64 DQ31
11 N/C 29 N/C 47 -WE 65 DQ15
12 A0 30 Vcc 48 N/C 66 N/C
13 A1 31 A8 49 DQ8 67 PD1
14 A2 32 A9 50 DQ24 68 PD2
15 A3 33 -RAS3 51 DQ9 69 PD3
16 A4 34 -RAS2 52 DQ25 70 PD4
17 A5 35 MP2 53 DQ10 71 N/C
18 A6 36 MP0 54 DQ26 72 Gnd
Note!! MP0,MP1,MP2,MP3 are N/C on all x32 bit modules
a9 is a N/C on 256k and 512k modules
a10 is a N/C on 256k, 512k, 1M and 4M modules
RAS1/RAS3 are N/C on 256k, 1M and 4M modules
Although there are 72 tabs on each side of the SIMM PCB there are
only 72 signal connectors on the SIMM socket and each tab is a
redundant connection.
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