Serial-to-Parallel Converter

This converter may help if just the serial port on a personal computer is free, whereas the printer needs a parallel (Centronics) port. It converts a serial 2400 baud signal into a parallel signal.The TxD line, pin 3, CTS line, pin 8 and the DSR line, pin 6, of the serial port are used — see diagram. The CTS and DSR signals enable handshaking to be implemented.Since the computer needs real RS232 levels, an adaptation from TTL to RS232 is provided in the converter by a MAX232. This is an integrated level converter that transforms the single +5 V supply into a symmetrical ±12 V one.