Pinouts
What is the pin out for ...?
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.
---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
- MIDI 5pin DIN
---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 Male
- SCSI Connector Pinouts (Single Ended) IDC-50 Male
- SCSI Connector Pinouts (Differential) IDC-50 Male
- Macintosh SCSI Connector Pinouts (Single Ended) DB-25S Female
---Video---
---Bus interfaces---
- ISA Bus Connector
- EISA Bus Connector
- VESA Local Bus (VLB) Connector
- PCI Cards Universal/3.3V/5V and 32/64 bit
---Misc---
- 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
EISA/ISA/VLB
-----------------------------------------------
| (component side) |
| |
| VLB __ ISA-16bit __ ISA-8bit __|
||||||||| ||||||||||| ||||||||||||||||||| A1(front)/B1(back)
| | | | | | | | | | | | | | <-EISA
C1/D1 E1(front)/F1(back)
G1/H1
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 Speaker Connector Turbo Indicator Connector
pin assignment pin assignment pin assignment
1 +12V 1 -Speaker 1 +5V
2 +12V return 2 [key] 2 -High Speed
3 +5V return 3 GND 3 +5V
4 +5V 4 +Speaker +5V
AT LED Power and Key Lock AT Backup Battery
pin assignment pin assignment
1 LED power 1 Batt+
2 GND 2 [key]
3 GND 3 GND
4 Key Switch 4 GND
5 GND
Motherboard Power Connectors
pin P8 assignment pin P9 assignment
1 Power Good 1 GND
2 +5v (or N.C.) 2 GND
3 +12v 3 -5v
4 -12v 4 +5v
5 GND 5 +5v
6 GND 6 +5v
MIDI 5pin DIN
MIDI In MIDI Out
pin assignment pin assignment
1 N/C 1 N/C
2 N/C 2 GND
3 N/C 3 N/C
4 Current Src 4 Current Sink
5 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 XT Keyboard Connector 5pin-DIN
pin assignment pin assignment
1 CLK/CTS (open-collector) 1 CLK/CTS (open-collector)
2 RxD/TxD/RTS (open-collector) 2 Keyboard Data
3 N/C 3 Reset
4 GND 4 GND
5 +5V 5 +5V
PS2 Keyboard/Mouse Connector 6pin-MDIN PS2 6pin-MDIN to AT 5pin-DIN Keyboard
pin assignment pin-PS2(F) pin-AT(M)
1 Data 1 2
2 N/C 2 N/C
3 GND 3 4
4 Vcc 4 5
5 CLK 5 1
6 N/C 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 Interface IDC-34 Male, IDC-20 Male
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 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 IDC-34 Male, IDC-20 Male
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 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
1 GND
2 GND
3 Red
4 Green
5 Blue
6 Intensity
7 (reserved)
8 Horizontal Sync
9 Vertical Sync
EGA DB9 Female
pin assignment
1 GND
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 Component Side Back Side Component Side
pin assignment |pin assignment |pin assignment |pin assignment
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) Connector
------------------------------
Back Side Component Side Back Side Component Side
pin assignment |pin assignment |pin assignment |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 Sel20 N/C
21 GND 22 GND
23 GND 24 GND
25 N/C 26 N/C
Null Modem:
Connector 1 to Connector 2
DTR DSR/DCD
DSR/DCD DTR
RTS CTS
CTS RTS
TXD RXD
RXD TXD
GND GND
Serial Port loopback:
Connected Pins
RX & TX
RTS & CTS
DCD & DTR & DSR & RI
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
Notes:
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
Notes:
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
25 TERMPWR |26 TERMPWR
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)
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
Notes:
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) 8.4 What size should I set my DOS partitions to be?
[From: Mike Long [Some corrections by: Osmo Ronkanen
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.
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
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.
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:
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.
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.
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.
[this section being worked on]
[this section being worked on]
[From: herbst@techunix.technion.ac.il (Herbst OMR)]
JUMBO TAPE
>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.
Windows:
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
Conner Basic 1.0
Conner Basic 1.1
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
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"
Symantec Norton Backup
Symantec Norton Backup for Windows
GNU-Tar
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.
[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%.
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.
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.
[From: scharf@mirage.nsc.com (Steve Scharf)]
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
Q) 8.5 How do I get DOS to letter my devices the way I want?
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
Q) 8.6 Why won't my system boot from the hard drive?
Q) 8.7 How do I clean my computer?
Q) 8.8 *What OS's are available for the PC? Which are free?
Q) 8.9 *How can I transfer files between my PC and a Unix system?
Q) 8.10 What tape backup software is available?
----------
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.
--------------------
Large with many, many features and confusing directory
selections. Works with most drives.
----------------
>From "Moshe Braner braner@emba.uvm.edu":
useless -- only backs up entire drive.
----------------
>From: pjk@netcom.com (Phil Koenig)
-----------
>From "Moshe Braner braner@emba.uvm.edu":
-------------------------------------------------------------------
Small and works fine. Works with parallel port Conner drive.
----------------------
This is included with Norton Desktop for Windows, which is a much
better deal than purchasing Norton Backup for Windows alone.
----------------------------------
-------
Q) 8.11 Why doesn't my new device work as fast as it should?
Q) 8.12 My drive lists a MTBF of 300,000 hours. Will it really last 34 years?
Q) 8.13 How do I find pin 1 on my chip/card/cable/connector?
Q) 8.14 I've run out of power connectors, what can I do?
Q) 8.15 What does FCC approval cover and what needs to be approved?
FCC Part 15 EMI Certification
and
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.
Motherboards
------------
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 problem with this concept is that there could be no guarantee that the
case that the motherboard was ultimately installed in, would be as good as
the one that it was originally certified in. It would be easy to manufacture
a very EMI tight case at great expense, inside which nearly any motherboard
could pass. I don't believe ANY 386 or greater class of motherboard could
pass outside of a case.
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.