Department of Computer Scien

ce and Information Engineering

National Cheng Kung University, TAIWAN

HANEL

OTHER MODES OF THE 8255Printer Signal

(cont

’)

‰As we can see from the steps above, merely presenting a byte of data to the printer is not enough

¾The printer must be informed of the presence of the data¾At the time the data is sent, the printer might be busy or out of paper

ƒSo the printer must inform the sender whenever it finally pick up the data from its data bus

‰Fig 15-16 and 15-17 show DB-25 and Centronics sides of the printer cable ‰Connection of the 8031/51 with the printer and programming are left to the reader to explore