PSone SIO0 Soldering Guide

This guide explains how to solder the SIO0 bus and RESET line on PSone consoles to enable the Virtual Memory Card and Reset via Gamepad features, where the required connectors are absent.

Caution

This is not an officially supported modification. It requires soldering experience and proper equipment.

The ArcStation manufacturer is not responsible for damage to the console or the ArcStation device caused by this modification.

Proceed only if you are comfortable soldering small PCB pads. If the console or ArcStation is damaged during this modification, the device may no longer be eligible for return or warranty service.

This guide assumes that you have already disassembled your PSone console, removed the upper metal shield plate, and have access to the top side of the motherboard PCB.

Here’s what you will need to complete the modification:

• 10-pin 1.0 mm pitch FFC/FPC adapter board. The Amazon link is only an example; you can use a similar adapter board from your preferred supplier.
• Thin wires. You will need to route wires between the upper metal shield plate and the plastic shell, so thick wires are not recommended.
• One wire with a female Dupont connector on one side.
• Soldering iron with a fine tip.
• Multimeter with continuity mode.

The flat cable for connecting ArcStation to the FFC/FPC adapter board is included in the cable set supplied with ArcStation.

Connecting SIO0

There are several PM-41 motherboard revisions used in PSone consoles. The exact PCB shape may differ from the diagram, but the SIO0 solder points are located in the same area and use the same layout.

Note

All solder points shown in the diagrams are circular, exposed, pretinned test pads. They are silver-colored and are not covered by the green solder mask.

If the point you are about to solder to is covered by solder mask, it is probably not the correct point.

Locate SIO0 solder points

Roughly locate the SIO0 Area as indicated by the red square on the motherboard overview diagram:

Then make sure you can identify each solder point as shown in the following zoomed-in portion of the motherboard diagram:

Solder adapter to PSone

Solder each bus signal to the adapter board:

Bus Line	Adapter Board Pad #
ACK	2
CS2	3
CS1	5
MISO	6
MOSI	8
CLK	10

Routing Tip

Plan ahead how long the wires need to be.

It is better to cut the wires slightly longer and solder them to all solder points on the motherboard first.

Then place the upper metal shield plate back on the console and route the wires on top of the shield, approximately where you want to place the adapter board.

After that, you can determine the required wire length, cut the wires to size, and solder them to the adapter board.

Verify connections

Now verify the connections. Without the upper half of the PSone case installed, you have access to the exposed Memory Card port contacts, which can be used as convenient test points.

Use a multimeter in continuity mode to check each connection. You can check continuity between a Memory Card port pin and the corresponding adapter board solder pad, the corresponding motherboard solder point, or both.

The following diagram shows where to connect the multimeter probe on the Memory Card ports for each bus line:

Final check

Take a 10-pin flat cable from the 2 × SIO0 10-pin flat cables bag included with the ArcStation cable set and connect one end to the adapter board.

Before powering the console on, you need to determine whether your FFC/FPC adapter board maps pin 1 to pin 1, or reverses the pin order. Different adapter boards may use different connector orientations.

Start by connecting the other end of the flat cable to the SIO MBOARD (1) connector on ArcStation.

Use a multimeter in continuity mode and check continuity between the CLK solder point on the PSone motherboard and the rightmost pin of the SIO MBOARD connector, marked as 2 in the diagram.

If you have continuity, the flat cable is connected correctly.

If you do not have continuity, disconnect the flat cable from SIO MBOARD and connect it to SIO FRONT (3) instead. Then repeat the same continuity check between the CLK solder point on the PSone motherboard and the rightmost pin of SIO MBOARD, marked as 2 in the diagram. Do not move the multimeter probe to SIO FRONT for this check.

Do not power on the console until this continuity check passes.

If you have continuity, you can turn on the console and check whether SIO0 is detected.

To check whether SIO0 is connected, open the ArcStation menu and press  → About.

If Peripherals Bus (SIO0) shows Connected, the uplink is using SIO0.

After that, you can test the VMC feature. Don’t forget to enable it in the settings. Check the reference page for details.

Connecting reset line

For the reset signal required for the Reset via Gamepad feature, the situation with different motherboard revisions is a little more complicated.

Without going too much into the details, the revision number postfix printed on the motherboard is not consistent and is only a vague indicator of the exact PCB layout.

For the purpose of locating the reset line solder point, we will divide motherboard revisions into two categories: “early” revisions and “later” revisions.

Identify revision

To identify which one you have, check the diagrams for both and select the one that matches your motherboard outline. “Early” revisions have rounded corners, and “later” revisions have chamfered corners.

Early revisions

Later revisions

Solder Dupont connector to reset line

Caution

The reset line is an open-collector/open-drain style signal. During normal operation it is pulled up, and during reset it is pulled down to GND.

This means that if you connect the ArcStation reset line to something other than the PSone reset line, that point will be shorted to GND for a brief time when you press the reset button combination on the gamepad.

Because of that, you must be sure that you are soldering to the correct solder point. Otherwise, the console or ArcStation may be damaged.

It is recommended to connect the ArcStation reset line to the PSone RST solder point through a resistor of approximately 330Ω to 470Ω. This limits the current in case the wire is accidentally soldered to the wrong point.

Cut a wire with a female Dupont connector so that one end has a loose wire and the other end has the connector.

Solder the loose wire to the RST solder point indicated in the diagram. Connect the Dupont connector side to the Reset pin on one of the POWER connectors on ArcStation.

When you have both SIO0 and Reset connected, you can test returning to the menu via the gamepad button combination. Don’t forget to enable the feature in settings. Check the reference page for details.