ZX Spectrum LPT Centronics Interface to interface a ZX Spectrum. ZX Spectrum 128 and/or ZX Spectrum Next with a vintage dot matrix printer with Centronics connector.

The interface uses a Z80 PIO to output 8 databits and a strobe pulse to send data to the printer, and an input to read the busy state of the printer.

The Printer can be connected with a flat cable. One and will have an IDC connector, the BOM list 40 pin header of which 36 pins will be used to connect to a Centronics plug at the other end. It is also possible to use a 14 pin centronics connector, the wireing is the same as used by the printer port of the MSX computer standard, an MSX 14 pin to 36 pin centronics cable will work.

It is possible to use a smaller IDC connector as the high pin numbers on the centronics connector are not actually used.

This interface works with the DK'Tronics software for the DK'Tronics interface which is available in the ZX Spectrum software repositories. It has been tested with the EPSON printer driver of this software package. The instructions provided with the DK'Tronics interface explain how to integrate the software in for example a word processing applications like Tasword II and how to make screen copies.

The jumper on the board selects which address line is used for I/O to the interface, selections are A2 (like the ZX printer) or A7 (as used the book "ZX Spectrum Hardware Manual"). The DK'Tronics software expects address A2 to be used. This will use ports 9B, BB, DB and FB. 9B is port A data out, port DB is port A control port, port BB is port B data out and port FB is port B control port,

For more information look up the Zilog Z80 PIO data sheet. Data out to the printer is connected to port A. Bit 2 of port B is strobe out, bit 7 of port B is input for the busy signal from the printer.