JRTwine Low Voltage Reset Circuit

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======== Assembling the Device ======
The LVR and LVR Custom PCBs are very easy to assemble together.  All you need is a 40-pin socket for the CPU, a 14-pin socket if you need the inverter to be installed, the DS1233 device and two 20-pin strips for the device connection to the board's CPU socket.  The 40-pin socket should be a ''ladder-type'' socket, preferably with only one "rung" in the middle of the socket, so that it does not interfere with the placement of the DS1233 device, or the CPU socket pins.

Before we get started, you have to carefully decide on the type of pins you are going to use.  If you use standard header-type pins which are commonly used with shorting blocks and look like this: 

{{ :headerpins.jpg?100 |}}

...those pins are quite a bit larger than standard IC legs and once you insert them into the socket on the board, you will permanently bend the fingers in that socket and that socket will no longer be useful if you remove the device.  You should use the thinner strip pins, which are harder to find and are a bit more expensive, which look like this:

{{ :strippins1.png?200 |}}

Since their pins are smaller, they are less likely to damage the socket.  You will also need at least two 40-pin sockets - one for the PCB and one used help align and protect the pins.

==== The Flip Side ====
OK - now, identify which side of the board is which.  The "parts" side is the side of the board with all of the silkscreen on it, and is where you will be doing most of the part-placing.  Conversely, the "solder" side of the board is the side where most of the soldering takes place.  On this PCB, you will placing parts and soldering on //both// sides.

==== Before you get Started - Sockets vs. Machine Pin Socket Strips ====
If you choose to do so, you can also use machine pin strip sockets instead of a conventional 40-pin socket as the CPU "socket."  If you do so, I suggest using an old 40-pin chip or a spare socket, insert its pins into the strip sockets, and use it as a way to align the strip sockets correctly.

==== Getting Started ====
First, you will position the socket that the CPU will plug into.  On the **parts** side of the board, place the 40-pin socket on the board using the pins that are closest to the top of the board (on the Custom board, these are the circular ones closest to the 40-21 silkscreen), and the ones furthest from the bottom of the board.  There are two dots near a set of pin holes that identify pin 1.

//Lightly// bend the corner legs a bit so that the socket remains in position when you turn the PCB over to expose the solder side - but **do not solder this socket in yet**!  This will serve as a guide so that you know which holes to solder the pin strips into (the remaining 2 rows - in retrospect, I should have placed markings on the solder side to clearly indicate the holes to use).  Here is where the socket should appear in both the 6809 and the Custom versions:

{{ :6809socket.png?400 |}}{{ :Customsocket.png?400 |}}

The remaining **circular** holes are where the CPU pins will go.  In order to ensure the strips are aligned correctly and to help protect the pins, insert them into another 40-pin socket, with the longer legs going into the socket, and leaving the shorter legs protruding from the socket.  Now align the pins with the two rows of holes from the **//solder//** side of the board.  Once in place, turn everything over whilst holding the pins in place, remove the //placeholder// socket off the parts side of the board, and solder the pin strips on the **//parts//** side of the board.  Leave the socket on these pins to protect them from getting accidentally bent or damaged.

==== Position the DS1233 Device ====
**BEFORE YOU PLACE THE DEVICE** \\ 
**BEFORE YOU PLACE THE DEVICE** \\ 
**BEFORE YOU PLACE THE DEVICE**\\ 
There is an error on the silkscreen on the v1.4 of the **6809** version and v1.0 of the **Custom** version.  The device needs to be mounted opposite of how it is shown on the silkscreen.  That is, when looking at the parts side of the board, with the text upright, the flat side of the device should face to the **left**, not to the right as indicated on the silkscreen.  The square pad, which is closer to the top of the board, is for Pin 1.

Now, place and solder the DS1233 device in the parts side of the board.  If you use the thru-hole version, there are two different ways to mount it.  If your socket is tall enough, you should be able to mount the device flush against the parts side of the board, right in its silkscreened position, and it should not protrude above the socket and interfere with the CPU being inserted into it.  

If not, leave enough of the leads above the board so that you can bend the device down at a just about a right angle so it fits in the void space that will be left when the socket is soldered in.  It should look kind of like this if you are bending it down:

{{ :6809pinsdevice.png?400 |}}

Once the device is in the correct position, solder it in place.

==== Place the CPU Socket ====
Lastly, place back the 40-pin socket that you first used on the parts side of the board, and solder it in place.  One everything is in position, it should look similar to these:

{{ :6809pinssocketdevice.png?400 |}} {{ :customsocketpinsanddevice.jpg?400 |}}

If you have determined you need the inverter (see the [[Configure]] page) solder its socket and place it into the socket.

If you are working with the **Custom** version of the device, you can now [[Configure|configure the device]], as detailed on the [[Configure]] page.