Computer To Printer Communication - Lexmark FORMS 249X Technical Reference

Computer to Printer Communication

The parallel interface transfers data from computer to printer. The data path is 8
bits wide. The printer and the computer synchronize data transfer with the
interface signals STROBE*, ACKNLG*, and BUSY.
When the computer is ready to send a byte of data to the printer, the computer
puts the byte of data on the data lines. Then the computer sends a STROBE*
(low) pulse to the printer. The printer responds with a BUSY (high) signal.
After the printer receives the data, the printer pulses the ACKNLG* (low) line.
This signals the computer that the printer has read the byte of data into printer
memory. If the printer buffers are not full and the printer can receive more data,
the printer removes the BUSY (low) signal.
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Section 6: Using the Printer Interface