Version 5 was the version that began to prove out the fact that Cartesian motion can be achieved with even rudimentary control software and electronics.
Due to a data crash that control software and associated models was lost. Only videos exist of the machine in operation.
One of the most important things that this version proved out was that even the most rudimentary designs can extrude molten plastic.
The extruder seen in the video uses a nozzle design that is unique in the 3d printer world. While not efficient it is very easy to fabricate.
The aluminum nozzle is flattened at the end by a mechanical means, with a piece of nichrome wire inside. Once the tube has been flattened, it is then cut through with a hand tool, cutting both the aluminum and the nichrome. The result is that the nichrome leaves an impression on the inside of the nozzle that is the same size as the original wire. The remaining part was then threaded. This is how the nozzle was made. The process took perhaps 10 minutes.