Having purchased and fitted the excellent vDrive ZX to an old Microdrive case, I now had the question of how to connect my working Microdrive to the vDrive. I’d bought the Microdrives separately and neither came with a through connector. I had a look around and realised that I could fashion one from a standard rear edge connector. The pin pitch is the same standard 2.54mm.
I borrowed an original connector from my friend Russell to check if the connections are straight through (gender reversers connect opposite pins). I used a multi-meter on it’s ohms (resistance) range to check and all the connections are straight from one side to the other. With that confirmed, I set to work making my substitute adaptor.
I used the original through connector as a template and pulled out pins from the long edge connector I was going to cut up. I started with one set of pins at the end and worked my way along. The reason for this is that cutting through the pins is difficult, noisy and can send the hacksaw blade off course. The method of pin removal I use to do this is to use a pair of tweezers to push each pin towards the center line of the connector from behind and then hook the end of the tweezers under the loop of the pin to pull it out. Be very careful not to pull more than one pin out at a time.
Once I had pulled all the necessary pins out, I set to work cutting the connector up. I used a bench mounted vice to keep the connector steady whilst I cut. A clamp on a bench would have worked equally well.
First, I cut the end off using the barrier between the pin sections as a guide for the hacksaw. I cut it nice and slow and let the saw do the work. On the next cut, again I used the barrier as a guide to cut as close to the pin chamber as possible. This process left the thin wall of the barrier intact. Continuing, I cut off the excess from the next connector before finishing with the last cut to separate the second part of the through connector from the edge connector strip.
Both the cut pieces needed to be tided up. I used some ‘pound shop’ sand paper. I did this roughly at first because I knew I was going to sand them further once the connector was soldered together.
Now the connectors were ready for connecting together. To make the connectors line up, I put a very small bend on the pins at the rear of the connectors. On one connector, I bent the pins in and on the other, I bent the pins out. This only had to be fractional and is just to allow the connectors to join in parallel. If you don’t do this, the connectors will be offset by a small amount. Although in practice this doesn’t affect operation of the drives.
I fixed the two connectors together with a piece of insulation tape to keep the two connectors stable whilst I soldered the end connections together. I Made sure to line up both key gaps together. You would be surprised how easy it is to get one inverted (Almost caught me out). Once the end pins were done, I removed the tape to gain access to solder the rest of the connections. Again, a clamp or blue tack could be have been used instead.
I then carefully soldered the pins at either end of the connectors, being careful not to use too much solder. I then checked the connections with an eye glass to make sure they were good before I removed the tape and soldered the rest of the connections.
As you can see, I needed to give the ends a little more work. I gave the ends of the combined connectors another sanding and cleaned off the resulting dust. The last step was to add the key. I find it easy to use a bit of strip board for this purpose. It breaks readily and you only need a small bit to do the job. A strip of three holes width is adequate. Once I had the strip, I inserted it into the connector as far as it would go and snapped it off close to the connector as I could.
I usually secure the strip board slice with some glue to prevent it from falling out later on. Connecting the drives together is exactly the same as you would do if you used an original connector. The only difference being that the drives aren’t flush together and you can’t connect the underside plate for stability. I have found that, in use, this hasn’t mattered since the edge connectors are a tight fit.
As you can see from the image, the drives stand apart a little but this doesn’t affect the operation at all. I do use the connected drives on a flat surface though.
Hopefully, this is a useful stop-gap whilst I source my own original connector. Or perhaps the home made connector will serve me well enough to keep in use.