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DonTronics Home Page DT204 Expansion Board for the SimmStickTM Bus.
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DT204: Expansion board for SimmStick Bus. This is a Two Inch Module. These DT204 Two Inch boards are $11AUD each.(~$9USD)
All of the documentation is now on this page.

SimmStick and other PCB Prices.

Free Local And International Air Mail Postage. on Printed Circuit Boards. Conditions Apply.


Schematic?  Not required as the 30 input signals simply connect to the 30 output signals.

Board Components and Assembly:
1 by DT204 PCB

Used just to add 4 slots to a bus and have the bus continue through.
Solder a pair of Dual 30 pin Simm Sockets on the component side of the board.
Solder a 30 pin right angle male connector to the input (SimmStick Bus end), and a 30 pin right angle female connector to the output.

You could plug it into a Simm Socket if you wish to leave the male pins off, as it is a SimmStick device in itself.

Used as a right angle or left angle bus connection, so that you can have a SimmStick facing up or down, or both.
Want to fit a ZIF socket to a SimmStick, or turn a SimmStick at 90 or 180 degrees to the normal?
Single or Dual Simm Sockets can be soldered on either the component or solder side of the board to suit your requirements. You can solder a right angle female 30 pin header socket on the output of the board, and make up a 30 pin male to a single row 30 pin Simm Socket just by soldering the two components together. This means you can have left, right, and extension boards all made from the DT204 Expansion board.

Signal Isolation and cross connection using either links or DIP switches.
If you wish to use the DT204 for this task, you must cut all the tracks on the component side of the board. Strange statement?, YES. There are 29 tracks in a straight row with one track missing. This is pin 9, which is the ground pin. This track is run on the solder side of the board and is always connected. This set of track cuts lines up with J2 on the overlay and runs along where the dotted line on the overlay is. There is also arrow markings on the component side of the board.

Once the 29 tracks have been cut, they must be re-joined in one of two ways.

  1. Solder a 2 by 30 set of male header pins into position J2, right above your track cuts. These can then be re-linked with standard test links or shunts.
  2. Solder in DIP Switches as indicated on the overlay. An 8 position Dip Switch will fit above signals 1 to 8. Pin 9 (GND) may be left blank, and another 8 position switch above pins 10 to 17, and another above 18 to 25. This leaves 5 signals remaining.

  3. If you are only using an 18 pin device, then this will do fine. If not, then you need to find a 5 position (or 6 if you cover pin 9 even though it isn't isolated) DIP Switch. These are around, but may be difficult to find. Certainly a 4 position can be got, so you may have to fit a set of male pins to the last position, signal D15, or pin 30.

    Solder a strip of 30 male pins into position J1, and another into J3.
    These pins are used to jumper around the now isolated bus.
    You may find test clips, female jumper leads, or wire wrap as suitable methods of re-joining and cross connecting your projects input/output signals.

Convert Simm connector to 30 pin Female.
Really covered above in most configurations. You just solder the set of 30 right angle female pins to the output of the board. Again you can make up a 30 pin straight male to a single row 30 pin Simm Socket just by soldering the two components together, so that you have an Extender board, just like in a PC. This will also allow ZIF sockets to be installed, or the board to be logically probed front and back, as it will now be above the other boards.
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