Card Type	Data acquisition
Chip Set	NEC 8253, 8255
I/O Options	Digital I/O ports (4), counter port
Data Bus	8-bit ISA

CONNECTIONS
Function	Label	Function	Label
Digital I/O port 1 (see pinout below)	CN1	8255 chip for port 4 (channel 7)	U3
Digital I/O port 2 (see pinout below)	CN2	8255 chip for port 4 (channel 8)	U4
Digital I/O port 3 (see pinout below)	CN3	8255 chip for port 1 (channel 1)	U6
Digital I/O port 4 (see pinout below)	CN4	8255 chip for port 1 (channel 2)	U7
8253 counter port (see pinout below)	CN5	8255 chip for port 2 (channel 3)	U8
8255 chip for port 3 (channel 5)	U1	8255 chip for port 2 (channel 4)	U9
8255 chip for port 3 (channel 6)	U2

CN1-CN4 PINOUT
Function	Pin	Function	Pin
Channel 1A bit 0	1	Channel 1C bit 2	19
Channel 1A bit 1	2	Channel 1C bit 3	20
Channel 1A bit 2	3	Channel 1C bit 4	21
Channel 1A bit 3	4	Channel 1C bit 5	22
Channel 1A bit 4	5	Channel 1C bit 6	23
Channel 1A bit 5	6	Channel 1C bit 7	24
Channel 1A bit 6	7	Ground	25
Channel 1A bit 7	8	Ground	26
Channel 1B bit 0	9	Channel 2A bit 0	27
Channel 1B bit 1	10	Channel 2A bit 1	28
Channel 1B bit 2	11	Channel 2A bit 2	29
Channel 1B bit 3	12	Channel 2A bit 3	30
Channel 1B bit 4	13	Channel 2A bit 4	31
Channel 1B bit 5	14	Channel 2A bit 5	32
Channel 1B bit 6	15	Channel 2A bit 6	33
Channel 1B bit 7	16	Channel 2A bit 7	34
Channel 1C bit 0	17	Channel 2B bit 0	35
Channel 1C bit 1	18	Channel 2B bit 1	36

CN1-CN4 PINOUT (CON’T)
Function	Pin	Function	Pin
Channel 2B bit 2	37	Channel 2C bit 1	44
Channel 2B bit 3	38	Channel 2C bit 2	45
Channel 2B bit 4	39	Channel 2C bit 3	46
Channel 2B bit 5	40	Channel 2C bit 4	47
Channel 2B bit 6	41	Channel 2C bit 5	48
Channel 2B bit 7	42	Channel 2C bit 6	49
Channel 2C bit 0	43	Channel 2C bit 7	50
Note:CN2 through CN4 are wired identically to CN1. CN1 has the signals for channels 1 and 2. CN2 through CN4 have the signals for channels 3 through 8, respectively.

CN5 PINOUT
Function	Pin	Function	Pin
Ground	1	Counter 2B clock signal in	18
Counter 1A clock signal in	2	Gate 2B signal	19
Gate 1A signal	3	Counter 2B clock signal out	20
Counter 1A clock signal out	4	Ground	21
Ground	5	Counter 2C clock signal in	22
Counter 1B clock signal in	6	Gate 2C signal	23
Gate 1B signal	7	Counter 2C clock signal out	24
Counter 1B clock signal out	8	Ground	25
Ground	9	+5V DC power	26
Counter 1C clock signal in	10	Ground	27
Gate 1C signal	11	-5V DC power	28
Counter 1C clock signal out	12	Ground	29
Ground	13	+12V DC power	30
Counter 2A clock signal in	14	Ground	31
Gate 2A signal	15	-12V DC power	32
Counter 2A clock signal out	16	Ground	33
Ground	17	Ground	34

USER CONFIGURABLE SETTINGS
Setting		Label	Position
»	Counter 1A uses internal clock source	JP1/A	Closed
	Counter 1A uses external clock source	JP1/A	Open
»	Counter 1B uses internal clock source	JP1/B	Closed
	Counter 1B uses external clock source	JP1/B	Open
»	Counter 1C uses internal clock source	JP1/C	Closed
	Counter 1C uses external clock source	JP1/C	Open
»	Counter 2A uses internal clock source	JP2/A	Closed
	Counter 2A uses external clock source	JP2/A	Open
»	Counter 2B uses internal clock source	JP2/B	Closed
	Counter 2B uses external clock source	JP2/B	Open
»	Counter 2C uses internal clock source	JP2/C	Closed
	Counter 2C uses external clock source	JP2/C	Open
»	Base I/O address set to 140h	JP3	Closed
	Base I/O address set to 100h	JP3	Open