CS401 Assignment 3 Solution Spring 2017

Questions No 01                                                                               20 marks

Suppose, you are interfacing an old monochrome dot matrix printer (receipt printer) with your computer’s parallel port. The stated dot matrix printer will print receipts character wise, so the system will transmit each character parallelly.

The printer will be operated as under:

  1. First, you should select the printer by setting “select printer” pin on your parallel port.
  2. Initialize printer by sending initialize signal.
  3. Read “acknowledge” pin.
  4. Transmit ASCII character data to the data port of the parallel port.
  5. Clear initialize signal.
  6. Deselect printer.

You should write a subroutine to print

“Welcome to Virtual University of Pakistan”

Your subroutine will get each character as an input from keyboard using interrupt mechanism and transmit it to the printer port according to the stated working mechanism.