S) 8.0 Misc

Q) 8.1 What is the pin out for ...?
[From: ralf@alum.wpi.edu (Ralph Valentino)]

This is a list of the pinouts to the more common PC hardware interfaces. It is by no means complete. While I have taken care not to make any mistakes, I urge you to take caution when using these tables. Also, please keep in mind that these are only tables, they are not a guide to hardware hacking and do not attempt to explain drive capabilities, signal timings, handling care, or other interface issues. As always, make sure you know what you're doing before you start hooking wires to your PC.

This section contains pinouts for:

I/O ports
Game Port DB15-Female
Serial Port DB9-Male DB25-Male
Serial Port loopback
Null Modem
Parallel Port DB25-Female
Parallel Port Centronics-36
Parallel Port loopback DB25-Male
Bidirectional ("Laplink") Parallel Cable DB-25 male to DB-25 male
10Base-T RJ-45 Male
10Base-T Crossover

Controller/Host Adapter
Floppy Disk Controller IDC-34 Male
IDE Hard Disk Interface IDC-40 Male
ESDI Hard Disk Interface IDC-34 Male, IDC-20 Male
RLL/MFM Hard Disk Interface IDC-34 Male, IDC-20
SCSI Connector Pinouts (Single Ended) IDC-50 Male
SCSI Connector Pinouts (Differential) IDC-50 Male
Macintosh SCSI Connector Pinouts (Single Ended) DB-25S Female

VGA DB15-S Female DB9 Female
CGA DB9 Female
EGA DB9 Female
VESA Standard Feature Connector

Bus interfaces
ISA Bus Connector
EISA Bus Connector
VESA Local Bus (VLB) Connector
PCI Cards Universal/3.3V/5V and 32/64 bit

Power Connector Male
Speaker Connector
Turbo Indicator Connector
AT LED Power and Key Lock
AT Backup Battery
Motherboard Power Connectors (8 pin, 9 pin)
AT Keyboard Connector 5pin-DIN
XT Keyboard Connector 5pin-DIN
PS2 Keyboard/Mouse Connector 6pin-MDIN
PS2 to AT Keyboard adapter
30 pin Fast Page Mode SIMM 256kx8 256kx9 1Mx8 1Mx9 4Mx8 4Mx9
72 pin Fast Page Mode SIMM 256k/512k/1M/2M/4M/8M x 32/36 bit

 5pin DIN Male          DB15-S Male                   6pin MDIN Male
    --+--               ----------------------                                  ---
   /  ^  \              \   1  2  3  4  5    /                                ] 2 1 [
  | 1   3 |              \ 6  7  8  9 10    /                               | 4   3 |
   \ 425 /                \ 11 12 13 14 15 /                          \6   5/
    -----                  ----------------                                        -^-

DB9 (DE-9) Male                DB15 (DA-15) Male
-------------                               --------------------------
\ 1 2 3 4 5 /                           \ 1  2  3  4  5  6  7  8 /
 \ 6 7 8 9 /                            \ 9  10 11 12 13 14 15 /
  ---------                                     ----------------------

DB25 Male                             IDC-50 Male
 ------------------------------        -------------------
 \ 1  2  3  4  5  7  8 ... 13 /       | 1  3  5  7 ... 49 |
  \ 14 15 16 17 18 .......25 /        | 2  4  6  8 ... 50 |
   --------------------------          -------------------

(Power Connector) Male              RJ-45 (8 conductor phone) Male
 /          \                         ------------------
| 4  3  2  1 |                        | 8 7 6 5 4 3 2 1 |
 ------------                         -------____-------

30 pin SIMM                         72 pin SIMM
-------------------------------     ---------------------------------------
|                             |     |                                     |
 )                            |      )                 _                  |
 --|||||||||||||||||||||||||---      --|||||||||||||||/ \|||||||||||||||---
   1           30          1    36  37     72

|            (component side)                 |
|                                             |
|   VLB   __ ISA-16bit __       ISA-8bit    __|
 |||||||||  |||||||||||  ||||||||||||||||||| A1(front)/B1(back)
             | | | | |    | | | | | | | | |   <-EISA
                   C1/D1                    E1(front)/F1(back)

        PCI Cards Universal/3.3V/5V and 32/64 bit.

PCI Universal Card 32/64 bit
|    PCI         Component Side (side B)                         |
|                                                                |
|                                                                |
|                                                optional        |
|    ____     mandatory 32-bit pins            64-bit pins  _____|
|___|    |||||||--|||||||||||||||||--|||||||--||||||||||||||
         ^     ^  ^               ^  ^     ^  ^            ^
       b01   b11  b14           b49  b52 b62  b63          b94

PCI 5V Card 32/64 bit
|                                                optional        |
|    ____     mandatory 32-bit pins            64-bit pins  _____|
|___|    ||||||||||||||||||||||||||--|||||||--||||||||||||||

PCI 3.3V Card 32/64 bit
|                                                optional        |
|    ____     mandatory 32-bit pins            64-bit pins  _____|
|___|    |||||||--||||||||||||||||||||||||||--||||||||||||||

Power Connector Male
pin assignment
1 +12V
2 +12V return
3 +5V return
4 +5V

Speaker Connector
pin assignment
1 -Speaker
2 [key]
4 +Speaker +5V

Turbo Indicator Connector
pin assignment
1 +5V
2 -High Speed
3 +5V

AT LED Power and Key Lock
pin assignment
1 LED power
4 Key Switch

Backup Battery
pin assignment
1 Batt+
2 [key]

Motherboard Power Connectors
pin P8 assignment P9 assignment
1 Power Good GND
2 +5v (or N.C.) GND
3 +12v -5v
4 -12v +5v
5 GND +5v
6 GND +5v

pin assignment
1 N/C
2 N/C
3 N/C
4 Current Src
5 Current Sink

pin assignment
1 N/C
3 N/C
4 Current Sink
5 Current Src

Floppy Disk Controller IDC-34 Male
pin assignment pin assignment
1 GND 2 Density Select
3 GND 4 (reserved)
5 GND 6 (reserved)
7 GND 8 Index
9 GND 10 Motor Enable A
11 GND 12 Drive Sel B
13 GND 14 Drive Sel A
15 GND 16 Motor Enable B
17 GND 18 Direction
19 GND 20 Step
21 GND 22 Write Data
23 GND 24 Floppy Write Enable
25 GND 26 Track 0
27 GND 28 Write Protect
29 GND 30 Read Data
31 GND 32 Head Select
33 GND 34 Disk Change

Game Port DB15-Female
pin assignment pin assignment
1 +5V DC 2 Button 4 (A_PB1)
3 Position 0(A_X) 4 GND
5 GND 6 Position 1 (A_Y)
7 Button 5(A_PB2) 8 +5V DC
9 +5V DC 10 Button 6 (B_PB1)
11 Position 2(B_X) 12 GND
13 Position 3(B_Y) 14 Button 7 (B_PB2)
15 +5V DC

Serial Port DB9-Male\DB25-Male
9-pin 25-pin assignment
1 8 DCD (Data Carrier Detect)
2 3 RX (Receive Data)
3 2 TX (Transmit Data)
4 20 DTR (Data Terminal Ready)
5 7 GND (Signal Ground)
6 6 DSR (Data Set Ready)
7 4 RTS (Request To Send)
8 5 CTS (Clear To Send)
9 22 RI (Ring Indicator)

Parallel Port DB25-Female
pin assignment pin assignment
1 -Strobe 2 Data 0
3 Data 1 4 Data 2
5 Data 3 6 Data 4
7 Data 5 8 Data 6
9 Data 7 10 -Ack
11 Busy 12 Paper Empty
13 Select 14 -Auto Feed
15 -Error 16 -Init
17 -Slct in 18 GND
19 GND 20 GND
21 GND 22 GND
23 GND 24 GND
25 GND

Parallel Port Centronics-36
1 -Strobe 2 Data 0
3 Data 1 4 Data 2
5 Data 3 6 Data 4
7 Data 5 8 Data 6
9 Data 7 10 -Ack
11 Busy 12 Paper Empty
13 Select 14 -Auto Feed
15 {OSCXT} 16 Signal GND
17 Frame GND 18 +5v
19 GND 20 GND
21 GND 22 GND
23 GND 24 GND
25 GND 26 GND
27 GND 28 GND
29 GND 30 GND
31 -Prime 32 -Error
33 Signal GND 34 N/C
35 N/C 36 N/C

10Base-T RJ-45 Male
pin assignment twisted pair color
1 TxData+ 2 White/Orange
2 TxData- 2 Orange
3 RxData+ 3 White/Green
4 - 1 Blue
5 - 1 White/Blue
6 RxData- 3 Green
7 - 4 White/Brown
8 - 4 Brown

10Base-T Crossover
Connector 1 to Connector 2
TxData+ RxData+
TxData- RxData-
RxData+ TxData+
RxData- TxData-

AT Keyboard Connector 5pin-DIN
pin assignment
1 CLK/CTS (open-collector)
2 RxD/TxD/RTS (open-collector)
3 N/C
5 +5V

XT Keyboard Connector 5pin-DIN
pin assignment
1 CLK/CTS (open-collector)
2 Keyboard Data
3 Reset
5 +5V

PS2 Keyboard/Mouse Connector 6pin-MDIN
pin assignment
1 Data
2 N/C
4 Vcc
6 N/C

PS2 6pin-MDIN to AT 5pin-DIN Keyboard
pin-PS2(F) pin-AT(M)
1 2
2 N/C
3 4
4 5
5 1
6 N/C

IDE Hard Disk Interface IDC-40 Male
pin assignment pin assignment
1 -Reset 2 GND
3 Data 7 4 Data 8
5 Data 6 6 Data 9
7 Data 5 8 Data 10
9 Data 4 10 Data 11
11 Data 3 12 Data 12
13 Data 2 14 Data 13
15 Data 1 16 Data 14
17 Data 0 18 Data 15
19 GND 20 Key
21 (reserved) 22 GND
23 -IOW 24 GND
25 -IOR 26 GND
27 IO Chrdy 28 Ale
29 (reserved) 30 GND
31 IRQ14 32 -IOCS16
33 Addr 1 34 (reserved)
35 Addr 0 36 Addr 2
37 -CS0 (1F0-1F7) 38 -CS1 (3f6-3f7)
39 -Active 40 GND

ESDI Hard Disk ESDI IDC-34
pin assignment pin assignment
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 Hard Disk Interface ESDI IDC-20
pin assignment pin assignment
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

RLL/MFM Hard Disk Interface RLL/MFM IDC-34
pin assignment pin assignment
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 Hard Disk Interface RLL/MFM IDC-20
pin assignment pin assignment
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

VGA DB15-S Female DB9 Female
15-pin 9-pin assignment
1 1 Red
2 2 Green
3 3 Blue
4 - Monitor ID bit 2
5 - N/C
6 6 GND (red return)
7 7 GND (green return)
8 8 GND (blue return)
9 - N/C
10 - GND
11 - Monitor ID bit 0
12 - Minitor ID bit 1
13 4 Horizontal Sync
14 5 Vertical Sync
15 - N/C

Monitor ID bit 0: reserved
Monitor ID bit 1: GND = mono, OPEN = color
Monochrome monitors use the green signal

CGA DB9 Female
pin assignment
3 Red
4 Green
5 Blue
6 Intensity
7 (reserved)
8 Horizontal Sync
9 Vertical Sync

EGA DB9 Female
pin assignment
2 Secondary Red
3 Primary Red
4 Primary Green
5 Primary Blue
6 Secondary Green / Intensity
7 Secondary Blue / Mono Video
8 Horizontal Drive
9 Vertical Drive

ISA Bus Connector EISA Bus Connector
Back Side pin assignment Component Side pin assignment Back Side pin assignment Component Side in assignment
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
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#
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
B17 DACK1# A17 SA14 F17 BE2# E17 BE1#
B18 DRQ1 A18 SA13 F18 BE0# E18 LA31#
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
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
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
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) Connector
Back Side pin assignment Component Side pin assignment Back Side pin assignment Component Side pin assignment
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
B18 Dat28 A18 Dat27
B19 Dat30 A19 Dat29 B48 RDYRTN# A48 LRDY#
B20 Vcc A20 Dat31 B49 GND A49 LDEV#
B21 Adr31 A21 Adr30 B50 IRQ9 A50 LREQ#
B22 GND A22 Adr28 B51 BRDY# A51 GND
B23 Adr29 A23 Adr26 B52 BLAST# A52 LGNT#
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#

VESA Standard Feature Connector
pin assignment pin assignment
1 PB 2 PG
3 PR 4 PI
5 SB 6 SG
7 SR 8 SI
9 Dot Clock 10 Blank
11 HSync 12 VSync
13 GND 14 GND
15 GND 16 GND
17 Ext Video Sel 18 Ext Sync Sel
19 Ext DotClock Sel 20 N/C
21 GND 22 GND
23 GND 24 GND
25 N/C 26 N/C

Null Modem
Connector 1 to Connector 2

Serial Port loopback:

Connected Pins

Bidirectional (Laplink/Interlnk) Parallel Cable DB-25 male to DB-25 male
Connector 1 to Connector 2
2 15
3 13
4 12
5 10
6 11
10 5
11 6
12 4
13 3
15 2
16 16
17 17
25 25

Parallel Port loopback DB25 Male

Connected Pins
2 & 15
3 & 13
4 & 12
5 & 10
6 & 11

30 pin Fast Page Mode SIMM 256kx8 256kx9 1Mx8 1Mx9 4Mx8 4Mx9
pin assignment pin assignment pin assignment pin assignment
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

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

72 pin Fast Page Mode SIMM 256k/512k/1M/2M/4M/8M x 32/36 bit
pin assignment pin assignment pin assignment pin assignment
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

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

SCSI Connector Pinouts (Single Ended) IDC-50 Male
pin assignment pin assignment pin assignment pin assignment
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 TERMPWR

SCSI Connector Pinouts (Differential) IDC-50 Male
pin assignment pin assignment pin assignment pin assignment
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

Macintosh SCSI Connector Pinouts (Single Ended) DB-25S Female
pin assignment pin assignment pin assignment pin assignment
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

PCI Cards Universal/3.3V/5V and 32/64 bit
pin assignment pin assignment pin assignment pin assignment
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)
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 Grou nd 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 AD[11] B94 Ground A94 reserved

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.

Q) 8.2 *Where are benchmark programs located. What do they mean?
Q) 8.3 What is Plug and Play?
[From: leefi@microsoft.com (Lee Fisher)]

Plug and Play is the name of a technology that lets PC hardware and attached devices work together automatically, reducing end-user complexity. Plug and Play technology is implemented in hardware, in operating systems, and in supporting software such as drivers and in the systemboard's BIOS. Microsoft will support Plug and Play starting with Windows "Chicago" and Windows NT "Cairo". Today there is a solution for MS-DOS and Microsoft Windows 3.x using software from Intel which works with the Plug and Play hardware. There are a variety of Plug and Play technologies, today including BIOS, ISA cards, SCSI, IDE CD-ROM, PCMCIA, drivers.

Many specifications are available via anonymous ftp at ftp.microsoft.com:/drg/Plug-and-Play. Email the PlayList@Microsoft.COM alias to get on a list for announcements regarding new specifications, informations on workshops, etc.

The Compuserve Plug and Play forum (GO PLUGPLAY) is available for technical support issues regarding hardware and driver design issues.

For more related information, on ftp.microsoft.com, see /drg/Plug-and-Play/readme and /drg/Developer-Info/devinfo.zip.

Microsoft is starting a "Plug and Play Hardware Catalog" to showcase Plug and Play hardware, entries are being accepted for the initial issue. Send hardware and company information to:
Plug and Play Catalog
c/o Microsoft Corporation
Hardware Vendor Relations Group, building 6
One Microsoft Way
Redmond, WA 98053-6399 USA

Q) What is an OEM product?
scott@bme.ri.ccf.org (Michael Scott)]

OEM versions of may computer products including keyboards, CDROM drives, video and sound cards, modems, monitors, popular software packages and more are available, either as parts of a computer system purchase, or as individual items. If you are considering a purchase of any OEM hardware or software, it's important that you understand what you are buying.

OEM stands for Original Equipment Manufacturer. OEM's exist in most major industries; Chrysler sells cars made by Mitsubishi, and all of Sear's Kenmore products are made by OEM companies. The main difference in the computer industry is that OEM products are usually less expensive than the retail versions supplied by the manufacturer. However, there are different types of OEM products.

Some manufacturers have two versions of their products; one retail version which ships in fancy packaging, and an OEM version which is sold in bulk (usually to system manufacturers). OEM products are not intended for individual sale, and so don't include a glossy box, and often don't include a manual or driver disks (if req'd).

Sometimes, the OEM versions are functionally identical to the original retail version, but not always. Often, a large system manufacturer will specify particular features in an OEM product which are not the same as the retail version. For example, Matrox supplies OEM video cards to a large manufacturer (i.e. Compaq's QVision 2000+ video card). Because of the large numbers purchased, Compaq gets a good price, and also specifies things like: amount of video RAM, upgradability, RAMDAC speed, etc. Part of the deal is usually that Compaq will take over responsibility for the hardware warranty.

Hypothetically, say that Matrox makes 10000 extra units in anticipation of Compaq's next order, with a few small BIOS tweaks for compatibility with Compaq's machines. Compaq decides they only need 8000 units this quarter, so Matrox sells the extra 2000 units as OEM. Once those units go out of the factory, they're no longer Matrox's responsiblity, and probably don't even have Matrox stamped on them anywhere.

I'm just using Matrox and Compaq for illustrative purposes here, but component manufacturers commonly provide OEM versions of their products for systems manufacturers. i.e. ATI, Tseng and Cirrus Logic provide chipsets for integration onto motherboards.

Sometimes, the difference between a retail version and the equivalent OEM is negligible, i.e. the packaging. However, more commonly the OEM version has been made with less expensive components, includes no software or hardware 'freebies' or extras, includes no hardware warranty, etc.

So, be careful when buying OEM that you are getting what you _think_ you are getting. You may be saving $20-30 and get a slower RAMDAC or a unit that isn't upgradable. On the other hand, you may be one of the thousands of people who have good success with their OEM products and saved some money at the same time.

Often, the OEM (original manufacturer) will not provide any tech support or warranty service for OEM units.

Q) 8.5 What size should I set my DOS partitions to be?
[From: Mike Long ( mike.long@analog.com)] [Some corrections by: Osmo Ronkanen ( ronkanen@cc.helsinki.fi)]

This depends on what cluster size you want. A smaller cluster size is better, because a small file takes up a whole cluster if there is even one byte in it; the leftover space is called "slack." If you have N files on your drive, and your cluster size is S bytes, then you can expect to lose N*S/2 bytes to slack space on the average.

The table below shows the maximum partition size to get clusters of a given size. You cannot format a hard drive under DOS with a cluster size less than 2K.

Cluster size Partition size FAT type Notes
4K (4096 bytes) 16 MB FAT12
2K (2048 bytes) 32 MB FAT16 (DOS versions < 4.0)
2K (2048 bytes) 128 MB FAT16 (DOS versions >= 4.0)
4K (4096 bytes) 256 MB FAT16
8K (8192 bytes) 512 MB FAT16
16K (16384 bytes) 1 GB FAT16
32K (32768 bytes) 2 GB FAT16
64K (65536 bytes) 4 GB FAT16

Another consideration is backup. If you backup to tape, you should have disk partitions smaller than the capacity of a single tape for ease in backup.

[From: Osmo Ronkanen ( ronkanen@cc.helsinki.fi)]

The 32 MB limit actually didn't have anything to do with the cluster size or FAT it was because the number of sectors in the partition was stored in boot record as a 16 bit number.

Q) 8.6 How do I get DOS to letter my devices the way I want?
The first floppy drive will always be A:, the second floppy drive will always be B:. If there is no second floppy, B: will also point to A:.

DOS will assign drive letters C: and up in the following order:

Primary DOS partition on each BIOS supported drive
(Master, Slave, EIDE ch2 Master, EIDE ch2 Slave)
All logical drives in the Extended DOS partition on each BIOS supported drive
(Master, Slave, EIDE ch2 Master, EIDE ch2 Slave)
Device drivers in CONFIG.SYS, in order, unless over ridden
Device drivers in AUTOEXEC.BAT, in order, unless over ridden

This table can be used to add drives without reordering drive letters. For instance, if you have a Master drive with a Primary and Extended DOS partition and you add a second (Slave) drive with a Primary DOS partition, all of your extended partitions will be re-lettered. If, however, you only place an extended partition on the new drive, all partitions on the Master will be assigned letters first.

Some device drivers, such as MSCDEX, have command line switches to specify an unused drive letter rather than the next open one. It is usually a good idea to set these to a higher drive letter right off rather than having to reinstall all of your software after adding another drive.

Q) 8.7 Why won't my system boot from the hard drive?
If you can boot from a floppy and see the files on your hard drive, then chances are there's something wrong with your MBR (Master Boot Record) / partition table. The first thing you should try is: "FDISK /MBR". This will fix the master boot record without effecting the contents of your disk. If this doesn't work, the next thing to try is verifying that you have your Primary DOS Partition set active. To do this, enter "FDISK" and chose "Set active partition" (usually the second option) then pick "Primary DOS Partition". Then exit and reboot. This too will not effect the contents of your disk.

The next thing to try is replacing the files required for DOS to boot; they may have been corrupted or deleted. To do this, run "SYS C:". This may or may not be possible as DOS versions before 5.0 required these files be located at a certain place on your hard drive and that spot may no longer be available. Either way, this will not otherwise effect the contents of your disk.

If neither of these things work, then the next thing to try is reformatting your hard drive (FORMAT C: /SYS). Note that this will erase all of the files on your hard drive, so back up anything you want to save first!!! If all three of these suggestions fail, then chances are you have a more serious problem.

Q) 8.8 How do I clean my computer?
Clean the outside with a damp (not wet) cloth with a mild dish washing detergent after unplugging the system. Let it dry completely before plugging your system in. Do not clean the inside - computer components are not susceptible to common house hold dust. Unless you have special equipment, you will more likely cause more harm than help to your computer if you try.

Q) 8.9 *What OS's are available for the PC? Which are free?
[this section being worked on]

Q) 8.10 *How can I transfer files between my PC and a Unix system?
[this section being worked on]

Q) 8.11 What tape backup software is available?
[From: herbst@techunix.technion.ac.il (Herbst OMR)]

Small. Not many features but does the job. Seems to work only with Colorado drives. Latest version is 4.03 and can be found by Archie jumbo403.zip.

From "Stan Faullin":
Useful DOS program. Has very basic Backup (total, modified, selected), Restore, Compare, Erase and Format functions. Some versions come with a Windows scheduler, but it will NOT run in the background in a DOS window. The compression scheme used in some previous versions is NOT compatible with their latest release, so you may not be able to read backups made with version 3.x with version 4.x. Separate versions of this software are available for their internal model or the parallel port model.

The Lite version supports both parallel port versions and internal versions. The only Windows backup program for a parallel port device, but only supports the Colorado Trakker unit. Can run in the background. Can be found by Archie, cbwlite.exe.

>From " gregb@oclflt.den.mmc.com (gregb)":

CMS Trakker 250 is supplied with a "generic" software package: it performs backup, restore, selective backup & restore, compression, compare. It works with DOS and Windows 3.1.

For an additional $49.95 ($39?) you can purchase their fancier version.

Central-Point backup
Large with many, many features and confusing directory selections. Works with most drives.

Conner Basic 1.0
>From "Moshe Braner braner@emba.uvm.edu":

useless -- only backs up entire drive.

Conner Basic 1.1
>From: pjk@netcom.com (Phil Koenig)

If you got the low-power backup software bundled in -- Conner Backup Basics -- and it is V1.0, you are entitled to a free upgrade from Conner. The new version has an only slightly better addendum to the manual, but the software now is about as flexible as most users would want -- partial backup and restore by directory or file, etc. It has worked well for us, and I recommend that you ask for your copy.

>From: dmiller@im.lcs.mit.edu (Dick and Jill Miller)

I emphasize that v1.1 of Conner Backup Basics fixes many of the prior problems, although its prompts, on-line help and printed documentation still deserve improvement.

Conner Exec
>From "Moshe Braner braner@emba.uvm.edu":

Very large (2.5 megs for DOS version, windows version even larger). Did not work with my parallel-port Conner 250meg QIC-80 drive.

QICstream==Conner "Simply Safe Software Backup Basics version 3.0P"
Small and works fine. Works with parallel port Conner drive.

Symantec Norton Backup
This is included with Norton Desktop for Windows, which is a much better deal than purchasing Norton Backup for Windows alone.

Symantec Norton Backup for Windows


Q) 8.12 Why doesn't my new device work as fast as it should?
The performance of individual components in your system are highly dependent the rest of your system. For instance, the transfer rate of drives, usually measured in megabytes per second, can depend on the drive controller, bus type and OS. Video card speed, sometime measured in Winmarks, highly depends on the speed of your main CPU as well as the OS. When ever you see a statement on the speed of the device, be sure to check the small print to determine what type of system and under what conditions the speed was measured. Don't be fooled by benchmark numbers. Another important corollary of this is *never* post benchmarks - they offer little to no information for comparison with other systems. Benchmarks are only useful for comparison purposes when run in a controlled environment, and even then to a limited degree.

Q) 8.13 My drive lists a MTBF of 300,000 hours. Will it really last 34 years?
[From: swwalters@fl51mail.space.honeywell.com (Steve Walters)]

Mean Time Between Failures (MTBF) is a statistical calculation indicating the mean time between randomly occurring hardware failures. Two parameters are necessary to fully describe how long a piece of hardware will last. The first parameter is MTBF which is a measure of frequency in which random hardware failures will occur. The second parameter is mean operating life which defines how long the hardware will last before an anticipated wearout phenomena will occur. These two parameters combined together give the true projection of the 'real' life of the drive. As an example of how these parameters interrelate, assume your drive has an MTBF of 300,000 hours and an operating life of 5 years. The drive will operate uninterrupted until failure (such as a file server, for example). This is telling you that your drive should be very reliable until wearout occurs since the MTBF greatly exceeds the mean life. However, after 5 years (on the average), expect it to fail due to wearout. In this example, the actual chances of the drive lasting 3 years is 92%, 4 years is 88%, 5 years is 56% and 6 years is 35%.

Q) 8.14 How do I find pin 1 on my chip/card/cable/connector?
Pin 1 is always marked in one way or another to avoid confusion due to symmetry (after which known numbering schemes can be used). The most important thing to note is that the orientation of the letters or numbers printed on the chip have absolutely nothing to do with the actual orientation of the pins. Never assume that all chips should be readable from the same angle!

The most obvious marking for pin 1 is a small number '1'. The first thing you should do is look very carefully for it. Ribbon cables are often marked with a blue or red stripe on pin 1. Some chips are marked with a dot, notch or small angled cut in the material just above pin 1. Rectangular chips are usually marked with a notch on one of ends; the first pin counter clockwise from this notch is pin 1. If you can't find a marking on the socket or connector, then try looking at the pads (the holes in the board the socket or connector is soldered into). For through-hole devices, pin 1 has a square pad, the rest should be round.

Q) 8.15 I've run out of power connectors, what can I do?
Assuming your power suply is actually strong enough to power all of your devices, you can pick up a Y-adapter at your local Radio Shack.

Q) 8.16 What does FCC approval cover and what needs to be approved?
[From: scharf@mirage.nsc.com (Steve Scharf)]

FCC Part 15 EMI Certification


UL/CSA/TUV Safety Certification

FCC Part 15 Certification of Computer Equipment
The basic thing to understand is that SYSTEMS are certified, Not individual circuit boards (though in most cases add-on cards ARE certified), not motherboards, not cases, and not power supplies.

Class A & B
Class A is for systems that will be used only in a commercial environment.
Class A is more lax than Class B.

Class B is stricter, and is for systems that will be used in a home.

A manufacturer cannot simply declare that a system is not intended for home use and test to the more lax Class A limits (believe me, they tried this). A high end file server with a RAID array of drives and multiple network connections would qualify for Class A. A simple Pentium 100 desktop or Power PC would not.

FCC Certified Peripherals and Add-On Cards
Most add-on cards and peripherals (disk drives, floppy drives, CD-ROM drives, tape drives, etc.) have their own FCC certification. This is so they can be sold separately. They would technically not need to be certified separately if the system in which they are installed is certified as a unit.

Once a SYSTEM has passed FCC certification, a manufacturer may swap or add FCC certified cards and peripherals and retain compliance even though the system may technically exceed the limit with the different peripherals. I believe the FCC still has the right to demand that the system be in actual compliance with the emissions limits.

The FCC has twice considered requiring motherboards be FCC certified and has twice rejected the idea. Of course there is great appeal to system manufacturers of this concept. Once a system is certified, the manufacturer could swap everything except the case and power supply and not have to re- test. The Independent Testing Labs were very vocal against the certification of motherboards since it would have seriously affected their business.

Power Supplies and Cases
Power supplies and cases are NOT FCC certified.

Keyboards and Mice
These are not required to be certified seperately if they are sold as part of a system, but in most cases they are certified separately so they can be sold separately.

Monitors, Printers, Externally Powered Peripherals
Each has their own certification. It actually has gotten very difficult to manufacture monitors that can meet Class B. This is why so many monitors have the plastic enclosed ferrite bead on the interface cable.

Swapping Motherboards, Power Supplies, and Cases.
You may not swap motherboards, power supplies, or cases, without re- certification. Bare Bones Systems
Some motherboard manufacturers sell 'bare bones' systems. This is the motherboard, power supply, and case, that has been FCC certified with some add-on cards and peripherals. The reseller can add any certified add-on cards and peripherals and retain compliance. For each new motherboard they recertify the bare bones system.

The bare bones system concept has not been very successful in the chop shop type stores. This is because the bare bones systems cannot use the lowest quality and cheapest case and power supply, and thus costs several dollars more than what a chop shop normally uses. The bare bones systems are also sometimes UL and CSA certified which necessitates better quality (and thus more costly) power supplies and cases.

How Add-On Card Makers Certify Their Cards.
What all add-on card makers do, is to certify their cards in a 'golden' system; a system with an excellent low noise (often low speed) motherboard and a high quality well shielded case and power supply. It isn't their problem to certify cards in a crappy and noisy system. The original IBM AT running at 6 Mhz is a popular system for certifying add-on cards, though of course this doesn't work anymore with PCI or VL bus cards.

How System Vendors Certify Their Systems.
What most system makers do is to certify their systems with the lowest noise add-on cards and peripherals they can find. Then they can swap in any FCC certified add-on cards and peripherals.

Thus the system you buy may legally be FCC certified even though it is over the emission limits. I think the FCC has built in leeway into the requirements to allow for this. I think that the FCC still has the right to insist that such a system meet the actual limits, but I doubt if they ever do anything about it.

How All The Small Stores Comply with FCC Part 15
Most small chop shop stores simply do not certify their systems. They are violating federal law and they usually get away with it since the FCC has very limited resources to enforce their rules.

The problem is actually solving itself as buyers become more educated. The systems assembled by the small stores are usually lower quality, often higher priced, and lack the warranty support of the systems sold by the top and middle tier vendors.

What About Build-It-Yourself
There is no certification requirement for do-it-yourself systems. However if their is a complaint lodged against you and the FCC investigates and finds you to be the cause of excessive emissions, then they can take action against you.

UL/ETL/CSA/TUV Safety Certification
UL-Underwriters Laboratories
CSA-Canadian Standards Association
TUV-German Safety Agency.
ETL-Electronic Testing Laboratories

These are product safety agencies. Most top tier systems are UL (or ETL)/CSA/TUV approved. Each agency now is supposed to inspect to the same international standards, but some policies are different in each agency.

The approval process is pretty simple despite all the requirements, but it can be costly so the cost needs to be amortized over a lot of systems.

This is a partial list of the requirements:

No high voltages can be accessible to the user, so the power switch may have no exposed contacts (this is a problem on some cheap cases). This is why the original PCs had a power supply with an integral switch on the side, and why the PS/2 had a front switch that was mechanically linked to the switch on the power supply by a long steel rod

The power supply must be UL/CSA/TUV approved (low quality power supplies cannot pass this approval so this is a good indication of at least minimal quality of a power supply).

All peripherals powered by the system must have fuses in the power lines. This means PS/2 mice and all keyboards. They don't want a short in the keyboard or mouse setting the cable on fire (this is ridiculous, since the power supply would shut down if the +5volts was shorted to ground, but it is still a requirement).

The lithium battery must be double protected against being charged by the system. Two diodes are typically used for this.

All circuit board materials must meet flame ratings.

Proper labeling of power connections, fuses, and switches is required.

There are limitations on the colors of switches and lamps, i.e. no red LEDs (which indicate danger).

All peripherals must be approved separately.

A 'finger' test to be sure that fingers cannot touch moving parts like fans is performed.

The agency will test the system FULLY LOADED with peripherals and load boards to simulate maximum power supply load. Afterwards, depending on the agency, you can swap approved peripherals. UL requires that you submit a list of which approved peripherals you will swap and investigates every one to be sure that current limits are not exceeded. CSA and TUV do not require this. UL is a royal pain, since there are so many different peripherals, and so many new ones are being introduced.

All plastics must be approved. The agency will attempt to set the unit on fire.

Towers are subject to a 'tip test,' which necessitates the use of bases on the case. Tower PC's are especially poorly designed for the tip test since all the heaviest components are at the top.

You must perform certain test procedures on each system to check shock hazards. This is called Hi-Pot testing. The test machines must be calibrated periodically.

You must affix proper labels, and there are very strict requirements on the materials, the ink, the logos, etc.

The agency will inspect your factory and then conduct periodic and/or random inspections to ensure that you are complying with all the rules.

Do You need these Safety Approvals?
In the United States there is no federal requirement that electrical equipment be approved. Some counties and cities DO have this requirement. Most recognize UL, ETL, or CSA, and some may recognize others as well.

Some bare bones systems have UL/CSA approval, but since UL must approve a system's peripherals as they change, it is uncommon. Some manufacturers are getting just CSA since it is valid in most places in the U.S. that require certification.

Companies that export systems to Canada and Europe must have the appropriate approvals.

As you would expect, very very few, if any, chop shops can get these safety approvals. In reality, the systems they build would be pretty close to passing, providing they use the proper power supplies and switches, since nearly all motherboards and peripherals meet the proper requirements.

The safety approvals do usually ensure a modicum of quality, since no fly- by-night factory could hope to meet the safety standards. Still there are instances of really poor equipment passing all the appropriate safety approvals.

As an aside, in Germany many types of products are subject to TUV testing, not just electronics. TUV designs appropriate tests for the product category. The bicycle/ski rack on the roof of my car is a TUV approved Thule rack, which has mounting systems far superior to their non-approved competitor. You can be fairly sure that it won't fly off the car at high speeds.

VDE Emissions Testing
Germany has different emissions requirements (which are accepted by most European countries). VDE emissions approval is difficult to obtain becaues there are only a couple of labs in the United States that VDE has allowed to certify systems. Thus, few PC's that are not intended for sale in Europe will have VDE approval.

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