Recently SUM ran an article on English keyboards available for Spectrum and 2068 users. At that time detailed instructions were not included on how to adapt the keyboard cable connectors to work with the T/S 2068. This article should help with that deficiency.
When installing the T/S 2068 in the various English keyboards that are available, three main areas are a problem:
- Finding a way to conveniently mount the 2068 motherboard in the keyboard case, since 2068 mounting holes are different from Spectrum.
- Modifying the case so that access to all necessary 2068 inputs and output connections is possible.
- Finding a way to connect the cables from the new keyboard to the 2068 motherboard.
There is no one way to solve the above problems. Each model of keyboard is different. Those keyboards with plastic cases can most easily be modified for #1 and #2. So we will concentrate on #3.
The 2068 keyboard is connected to its motherboard by a single ribbon cable of 13 conductors (lines) plugging into a single 13 connection socket.
Meanwhile, the Spectrum and Spectrum Plus connect to their motherboards with two cables, one of 8 and one of 5 lines, running to two separate sockets located at different places on the motherboard. An additional difference with the 2068 is that the 5 connector ribbon and socket have their connections on the other side of the ribbon as compared to the same 5 lines on the 2068. This makes it impossible to plug either the Spectrum Plus or other English keyboards into the single 2068 socket simply by laying the 8 and 5 lines cables side by side and plugging in. So we need to find a way to get the contacts on the other side of the 5 line ribbon cable.
- If it is only a ribbon cable (no small circuit board or stiff plexiglass on its end) and the cable is flexible enough, bend the end into a U shape with the traces to the outside. Be very careful not to break the conducting traces. Do not bend more than once as bending back and forth will break them. Now insert the cable in the 2068 socket along side the 8 line cable (8 + 5 = 13!).
- Some keyboard cables have small circuit boards soldered to the end that plugs into the motherboard connector. The one on the five line cable can be unsoldered, turned over and re-soldered to the ribbon cable. It can now be plugged into the 2068 motherboard (though you may need to trim the edges of the boards to make them fit in side by side).
- Some English keyboards give access to the 5 line cable where it attaches to the English keyboard. If so, it may can be turned over and re-connected there (often by means of a clip). Thus turning the cable over makes everything right at the motherboard end.
- One last problem is having cables that are too short for one or both to reach the 2068 connector. The reader will have to be left to his own solutions on this. one. Installing a longer pair of cables would be the easiest IF a source for the ribbon cable material.