The Flash/EPROM Adaptor construction

If you ordered a kit, you should have gotten the components on this picture, but only one of the 24pin or 28pin adaptor, depending on the type of kit you ordered. If you ordered just the PCB, you'll have to get these or similar components yourself (see the main page for a parts list).


Assembling the device includes a few tricky steps, especially installing the socket adaptor. So I'll describe how I do it. Note that you have to do the configuration steps first, before you start soldering the components!

Turn over the PCB and solder the SMD resistors onto their pads. Please refer to the main page for a description of how many of the resistors are needed for the version of the adaptor you want to build and onto which pads they have to be installed.

The easiest way to solder the resistors is the following: add some solder to one of the pads, then place the resistor there with a pair of small tweezers and heat the solder pad again. The resistor will now be glued into place. Now heat the other pad and add some solder, and be sure not to heat the pad too long, or the first pad will get loose again.

Now you can put the socket adaptor into place, the thicker pins are inserted into the holes. See the next step for more details.
You have two options to install the adaptor socket: low profile or high profile. If you are going to install the adaptor into a machine with limited space, choose the low profile version as shown on the left side: As an extra step, one row of pins has to be cut off with a wire cutter to allow the socket for the Flash chip to be installed. In the picture, the right row has been cut off. In the high profile version, the adaptor socket is only inserted as far that the Flash socket can be installed without problems. After cutting off the pins (if needed) solder the pins from the top side of the board.

If you use a precision IC socket you probably won't have to cut off any pins for the low profile version. This depends a lot on the type of IC socket and socket adaptor you use.
Now install the IC socket from the top side and solder it from the bottom side. Soldering the low profile version is a little bit tricky, because some pins are hidden behind the plastic bars of the socket adaptor. When you put the soldering iron carefully from one side and apply solder from the other side of these bars, the socket can be soldered without melting the plastic.
As the final step, solder the wires coming from the banking switches (if you have any) to the jumper connectors J1 to J5. Then you can insert the Flash chip and install the adaptor in your machine.

The picture shows a hex coding switch that allows the use of 16 different 8kB ROM images with a single switch. Unfortunately such a switch costs more than EUR 3.00, so I don't have them in stock.


If you have questions about this project,  you can mail me: please visit my contact page.