Backplane

Backplane Overview

The connectors are as follows (starting on the backplane PCB from the left to the right):

Configuration DIP-Switches

• RPL: enable/ disable 2 plays per coin
• 2PL: enable/ disable extented play in Hyperspace
• TST: enable/ disable test pattern

As you might have noticed, there is a mismatch between the labeling and the actual function. To prevent any confustion: the RPL and 2PL labels on the backplane PCB are wrong, this documentation is right. This will be fixed in a follow-up version of the design files.

Control Panel connector

The backplane board uses a 12 pin IDC connector for connection of the control panel. The pin-layout is as follows (birds-eye view in direction to the top-side of the backplane PCB):

5VDC-SB

This 2 pin male pinhead connector provides 5VDC standby power. Those are available, even with a powered down PC PSU and unpowered PCB's. This can be handy to power low voltage maintenance tools, while all CS PCB's are safely powered down. Watch indicated polarity!

PSU

Standard 24 pin Molex connector with a compatible pin layout for PC power supply units. It provides...

• 5VDC
• 12VDC
• 5VDC stand-by
• connectivity for power switch
• connectivity for power-on LED indicator

Power switches and power indicator LED

• board mounted switch to manually power-on the attached PSU
• 2 pin male pinhead connector for door switch
• LED for indication of stable power supply (controlled by attached PSU)

Cooling Fan power connectors

There are two 2 pin male pinhead connectors with either 5VDC or 12VDC, intented for powering cooling fans. Watch indicated polarity!

Coin Counter Connector

The connector uses 12VDC from the external power supply and the signaling, coming from CS sync board.

Audio/Video connectivity

There are two alternative options for connecting audio and video signals. Both sharing the same signal source, just providing different connector types.

3pin male pinhead connector, labeled V-A-C

• V: Video signal (color code violet/black)
• A: Audio signal (color code blue)
• C: Common ground (color code violet)

RCA Connector

The RCA connector provides connectivity for 3 chinch plugs:

• top-most: Video signal
• middle: Audio signal
• bottom-most: Audio signal (same as the middle one, supports provision of mono sound to both stereo speakers)

This specific type of RCA connector was choosen because of its small footprint that is preferable, considering the limited space on the backplane PCB. However, it seems to be rare and might be difficult to source.

Some potential sources as of 2025-05 are

• Elecbee.com
• Alibaba
• AliExpress
• eBay

In case of doubt, here is a reference photo of the relevant type:

12VDC-Output

It is possible to power a 12VDC (LCD) monitor. The 12VDC are comming directly from the attached PSU, from a 12VDC rail that exclusively used for this purpose. Make sure, that the power consumption remains within the limits of the PSU and take care of correct polarity!

Relay Replacement

The default configuration of the CS sync-board requires a relay with a release-time of approx. 250µs. In case, that a proper replacement has to be sourced and might be challenging to find, an optocoupler replacement can be used.

The relay replacement uses an 4N25 optocoupler IC. It consists of an internal IR LED and an IR phototransistor. The internal IR LED requires an 360 Ohm resistor to adapt the 5VDC of the CS sync-board to an appropriate level. Therefore the orientation of the relay replacement board, relative to the sync-board is importand and must be as follows:

Test Harness

Unfortunately, as the test harness PCB is designed, sticking out on the left side of the upright CS-PCB stack, it is only compatible with the backplane PCB that is also published on this Github repository.

The harness ist tested and works fine with wire lengths of approximately 500 mm (~ 20 inches).

It is highly recommended, to double check the matching of each single line between the test harness PCB and the connector with a multimeter in continuity mode. In addition, there should be a clear indicator for the connectors orientation (e.g. using a different color for at least one wire isolation on connector pin 1). This is important as mismatching lines and/or wrongly attached card edge connector could cause damage to the boards/components.