DECISION COMPUTER INTERNATIONAL CO., LTD.
8255/8253 I/O CARD
Card Type | Data acquisition |
Chip Set | NEC 8255 |
I/O Options | Digital I/O ports (2) |
Data Bus | 8-bit ISA |

CONNECTIONS | |||
Function | Label | Function | Label |
Digital I/O port 1 (see pinout below) | CN1 | Digital I/O port 2 (see pinout below) | CN2 |
CN1 PINOUT | |||
Function | Pin | Function | Pin |
Ground | 1 | Channel 1C bit 6 | 21 |
Ground | 2 | Channel 1C bit 7 | 22 |
Ground | 3 | Channel 1C bit 4 | 23 |
Channel 1A bit 3 | 4 | Channel 1C bit 5 | 24 |
Channel 1A bit 1 | 5 | Channel 1C bit 1 | 25 |
Channel 1A bit 2 | 6 | Channel 1C bit 0 | 26 |
Clock signal 0 in | 7 | Channel 1B bit 7 | 27 |
Channel 1A bit 0 | 8 | Channel 1C bit 2 | 28 |
Gate signal 0 | 9 | Channel 1B bit 6 | 29 |
Clock signal 0 out | 10 | Channel 1C bit 3 | 30 |
Clock signal 2 out | 11 | Channel 1B bit 5 | 31 |
Clock signal 2 in | 12 | Channel 1B bit 0 | 32 |
Clock signal 1 in | 13 | Channel 1B bit 4 | 33 |
Gate signal 2 | 14 | Channel 1B bit 1 | 34 |
Clock signal 1 out | 15 | Channel 1B bit 3 | 35 |
Gate signal 1 | 16 | Channel 1B bit 2 | 36 |
Channel 1A bit 5 | 17 | +5V power | 37 |
Channel 1A bit 4 | 18 | -5V power | 38 |
Channel 1A bit 7 | 19 | +12V power | 39 |
Channel 1A bit 6 | 20 | -12V power | 40 |
CN2 PINOUT | |||
Function | Pin | Function | Pin |
Ground | 1 | Channel 2C bit 7 | 21 |
Ground | 2 | Channel 2C bit 6 | 22 |
Ground | 3 | Channel 2C bit 5 | 23 |
Ground | 4 | Channel 2C bit 4 | 24 |
Ground | 5 | Channel 2C bit 0 | 25 |
Ground | 6 | Channel 2C bit 1 | 26 |
Ground | 7 | Channel 2C bit 2 | 27 |
Ground | 8 | Channel 2B bit 7 | 28 |
Ground | 9 | Channel 2C bit 3 | 29 |
Ground | 10 | Channel 2B bit 6 | 30 |
Ground | 11 | Channel 2B bit 0 | 31 |
Ground | 12 | Channel 2B bit 5 | 32 |
Channel 2A bit 0 | 13 | Channel 2B bit 1 | 33 |
Channel 2A bit 1 | 14 | Channel 2B bit 4 | 34 |
Channel 2A bit 2 | 15 | Channel 2B bit 2 | 35 |
Channel 2A bit 3 | 16 | Channel 2B bit 3 | 36 |
Channel 2A bit 4 | 17 | +5V power | 37 |
Channel 2A bit 5 | 18 | -5V power | 38 |
Channel 2A bit 6 | 19 | +12V power | 39 |
Channel 2A bit 7 | 20 | -12V power | 40 |
USER CONFIGURABLE SETTINGS | |||
Setting | Label | Position | |
| » | Counter 0 uses internal clock source | JP1/A | Closed |
Counter 0 uses external clock source | JP1/A | Open | |
| » | Counter 1 uses internal clock source | JP1/B | Closed |
Counter 1 uses external clock source | JP1/B | Open | |
| » | Counter 2 uses internal clock source | JP1/C | Closed |
Counter 2 uses external clock source | JP1/C | Open | |
| » | Base I/O address set to 1B0h | JP2 | Closed |
Base I/O address set to 1F0h | JP2 | Open | |
DIAGNOSTIC LED(S) | |||
LED | Color | Status | Condition |
1PA0 | Red | On | Channel 1A bit 0 is active |
1PA0 | Red | Off | Channel 1A bit 0 is not active |
1PA1 | Red | On | Channel 1A bit 1 is active |
1PA1 | Red | Off | Channel 1A bit 1 is not active |
1PA2 | Red | On | Channel 1A bit 2 is active |
1PA2 | Red | Off | Channel 1A bit 2 is not active |
1PA3 | Red | On | Channel 1A bit 3 is active |
1PA3 | Red | Off | Channel 1A bit 3 is not active |
1PA4 | Red | On | Channel 1A bit 4 is active |
1PA4 | Red | Off | Channel 1A bit 4 is not active |
1PA5 | Red | On | Channel 1A bit 5 is active |
1PA5 | Red | Off | Channel 1A bit 5 is not active |
1PA6 | Red | On | Channel 1A bit 6 is active |
1PA6 | Red | Off | Channel 1A bit 6 is not active |
1PA7 | Red | On | Channel 1A bit 7 is active |
1PA7 | Red | Off | Channel 1A bit 7 is not active |
2PA0 | Red | On | Channel 2A bit 0 is active |
2PA0 | Red | Off | Channel 2A bit 0 is not active |
2PA1 | Red | On | Channel 2A bit 1 is active |
2PA1 | Red | Off | Channel 2A bit 1 is not active |
2PA2 | Red | On | Channel 2A bit 2 is active |
2PA2 | Red | Off | Channel 2A bit 2 is not active |
2PA3 | Red | On | Channel 2A bit 3 is active |
2PA3 | Red | Off | Channel 2A bit 3 is not active |
2PA4 | Red | On | Channel 2A bit 4 is active |
2PA4 | Red | Off | Channel 2A bit 4 is not active |
2PA5 | Red | On | Channel 2A bit 5 is active |
2PA5 | Red | Off | Channel 2A bit 5 is not active |
2PA6 | Red | On | Channel 2A bit 6 is active |
2PA6 | Red | Off | Channel 2A bit 6 is not active |
2PA7 | Red | On | Channel 2A bit 7 is active |
2PA7 | Red | Off | Channel 2A bit 7 is not active |