Appendixes
Interfaces
Parallel Interface
Specifications
Transmission mode | |
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Receive buffer size | 16K bytes |
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Transmission modes | Compatible mode |
| It is an asynchronous forward direction of the byte width |
| (from host to printer) channel, and the interface line of |
| the data is operated in accordance with signal line |
| definitions of Centronics. |
| NIBBLE mode |
| Nibble mode is asynchronous reverse channel |
| communication with data transmission controlled by the |
| host computer. In reverse channel transmission, the data is |
| nibble transmitted in two parts using four status lines (Fault, |
| Select, PE, and Busy). And nibble mode can be used along |
| with compatible mode to send data in two directions. |
| ECP mode |
| ECP mode permits |
| transmission, and thanks to its interlock handshake, it does |
| not require the timing necessary with compatible mode. |
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Signal level | IEEE1284 standard |
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Signal line and pin assignment table
Pin No. | Signal name | I/O | Function |
1 | *STROBE | Input | Strobe signal to read in |
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Input | |||
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10 | *ACKNLG | Output | |
11 | BUSY | Output | Signal specifying printer busy |
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12 | PERROR | Output | Signal specifying media out |
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13 | SELECT | Output | Signal specifying if the printer is |
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| enabled) or |
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14 | AUTOFD | Input | Invalid (ignored) |
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15 | NC | Not used | |
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16 | GND | Signal ground | |
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17 | FGND | Frame ground | |
18 | P.L.H | Output | Peripheral logic high (pull up to +5V at 1kΩ) |
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GND | Ground for twisted pair return | ||
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31 | *INIT | Input | Printer reset |
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32 | *FAULT | Output | Signal specifying printer error |
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NC | Not used | ||
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36 | SELECTIN | Input | Invalid (ignored) |
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