serial port wiring - UK Vintage Radio Repair and Restoration Discussion Forum

Kat Manton · 23rd Apr 2007, 7:38 pm

There were two ways which the serial port header on the mainboard was wired, consequently there were also two different ways in which the ribbon cable was wired up to the 9-pin-D connector.

They're not compatible. One wiring scheme has the wires from the ribbon soldered alternately to pins on the top and bottom rows of the D-connector. The other wiring scheme has the wires from the ribbon split, one half goes to the top row of the D-connector, the other half to the bottom row.

This page explains it well, along with photographs of both wiring schemes.

Cheers, Kat

23rd Apr 2007, 7:38 pm	#1
Kat Manton Retired Dormant Member Join Date: Jul 2005 Location: West Yorkshire, UK. Posts: 1,700	serial port wiring There were two ways which the serial port header on the mainboard was wired, consequently there were also two different ways in which the ribbon cable was wired up to the 9-pin-D connector. They're not compatible. One wiring scheme has the wires from the ribbon soldered alternately to pins on the top and bottom rows of the D-connector. The other wiring scheme has the wires from the ribbon split, one half goes to the top row of the D-connector, the other half to the bottom row. This page explains it well, along with photographs of both wiring schemes. Cheers, Kat