SC109, v1.0, Assembly Guide

Click here for a list of the parts required to build an SC109, v1.0, Modular Backplane Bridge.

Experienced builders can just go ahead and populate the board. There shouldn’t be any surprises to catch you out.

This guide assumes you are familiar with assembling circuit boards, soldering, and cleaning. If not, it is recommended you read some of the guides on the internet before continuing.

First check you have all the required components, as listed in the parts list.

Before assembling it is worth visually inspecting the circuit board for anything that looks out of place, such as mechanical damage or apparent manufacturing defects.

If you have a multimeter that measures resistance or has a continuity test function, check there is not a short on the power supply tracks. Connect the probes to each terminal of one of the capacitors, such as C1. This should be an open circuit, not a short.

The picture below shows what a completed SC109 Modular Backplane Bridge should look like.

Male bus headers

Fit and solder the Z50Bus male bus header pins (shown below in red).

This fits over the edge of the PCB as illustrated above.

A good strategy for fixing this so the pins are parallel to the circuit board, is to solder one pin near each end, on one side of the board. Check the pins are parallel and adjust if necessary. Now solder a similar pair of pins on the other side, and again adjust as necessary. Now solder a few on each side, then swap sides until all the pins are soldered.

Fit and solder the RC2014 bus male header pins (shown below in yellow).

Bus sockets

Fit and solder the Z50Bus sockets (shown below in red).

Fit and solder the RC2014 bus sockets (shown below in yellow).

Jumper Header Pins

Fit and solder the jumper header pins (shown below in yellow).

Capacitors (100 nF)

Fit and solder the 100 nF capacitors, C1 to C6 (shown below in yellow).

These can be fitted either way around as they are not polarity dependent.


Remove any solder ‘splats’ with a brush, such as an old toothbrush.

Visually inspect the soldering for dry joints and shorts.

Clean the flux off with suitable cleaning materials.

Visually inspect again.

If all is well, go ahead and give it a try.

Homebrew 8-bit retro computing