PNC-3000 Part 2

While waiting for the bearings for the spindle and motor, I might as well start looking at the electronics. The back of the mill looks like this:

It might look a bit complex, but really it isn't.. Looking at the schematics was a trip down memory lane, the design is a classic microprocessor construction with everything you'd expect to find in such a design. RAM, ROM, address decoder addressable IO chips, external serial driver etc.

The plan is to hook into the clock, step, and power down signals for the three axis, which comes from a 82C55 IP chip, so first step was to remove this.

I must admit that it does hurt a bit doing this to vintage electronics like this, but in the end it should end up being a much more versatile mill, while still being almost original.

Preserving the original electronics means that the coordinate display will still be working, but it will only be possible to display the machine coordinates, not your work coordinate system, since there is no way of feeding offsets into the machine.




Since I already had access to the electronics, I figured that I might as well take a backup of the EPROM's, and no backup is complete without also testing if you can restore it again..

I haven't programmed EPROM's for a while.. 😁