Appendix B: Pinout Specifications
Serial Models | DB25 Female |
Pin | Signal Name | Acronym | I/O | Description |
2 | Transmit data | TXD | Output | Serial data from port |
3 | Receive data | RXD | Input | Serial data to port |
4 | Request to send | RTS | Output | Always high |
6 | Data set ready | DSR | Input | Low inhibits transmit data |
7 | Signal ground | GND | Common |
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20 | Terminal ready | DTR | output |
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Pin 20 is the hardware flow control output. Pin 6 is the hardware flow control input. Pin 6 has an internal
Parallel Models | Centronics 36 Female |
DB25 Female
C36F | DB25 |
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Pin | Pin | Signal Name | Port 0 | Port | Description |
1 | 1 | STROBE | output | input | Data transfer when pulsed low |
2 | 2 | DATA 0 | output | input | Data LSB |
3 | 3 | DATA 1 | output | input |
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4 | 4 | DATA 2 | output | input |
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5 | 5 | DATA 3 | output | input |
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6 | 6 | DATA 4 | output | input |
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7 | 7 | DATA 5 | output | input |
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8 | 8 | DATA 6 | output | input |
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9 | 9 | DATA 7 | output | input | Data MSB |
10 | 10 | ACK | input | output | Pulsed low for next transfer |
11 | 11 | BUSY | input | output | If high inhibits data flow |
12 | 12 | PAPER END | input | output | Input unused, low when output |
13 | 13 | SELECT OUT | input | output | Input unused, high when output |
14 | 14 | AUTOFEED | output | input | Input unused, output high |
16 |
| GROUND | Wired common all ports | ||
GROUND | Wired common all ports | ||||
31 | 16 | INITIAL | output | Input | Must be high to receive data |
32 | 15 | ERROR | Input | output | Input unused, high when output |
33 | - | GROUND | Wired common all ports | ||
36 | 17 | SELECT IN | output | input | Must be low to receive data |
CARETAKER PLUS INSTALLATION AND OPERATIONS MANUAL
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