Simple RS232 for Printer usage
Chip Chat RS232 Printer interface by John Harden. Only the transmit direction is implement, so it can't do much more than accessing RS232 printers, but no other RS232 devices. The device connects to the printer port, however, the hardware does not convert the parallel printer data to serial data. The included sample program does that conversion by software. The circuit was released in Amstrad Action #27 magazine.