Reverse engineering vintage PCBs

I appreciate all the input from folks. With 3600 though holes and at least 4 layers, I'm afraid I will make mistakes using any manual method like ohm tracing without a check or balance. With so many permutations and little personal knowledge about the WE chipset, I'm sure I will miss an occasional trace that shoots to the other side of the board. I'm also worried that I might generate a false positive keeping most of the components wired. Something akin to body diodes (yes I know this isn't CMOS). Here is a wiki photo of the board for reference: http://en.wikipedia.org/wiki/3B_series_computers#mediaviewer/File:3b2-300-m… As I said the board isn't very useful in it's current state. So I will start by dropping the components off and removing the solder mask with a sanding pen. I've had good luck in the past photo transferring a scanned image of the board into eCAD with contrast enhancement. That will at least get me the top and bottom layers with good accuracy. If manual tracing of inner layers proves to laborious, I'll revisit automated methods. To add to Chuck's question, I've thought about that too. With the open nature of KiCAD and Eagle file formats, it should be straight forward to generate a schematic from a text netlist (or even IPC-D-356). Especially since both contain definitions for the referenced schematic symbols. eg you can synth a 'generic' DIP-16-U<n> symbol to go with that yet to be defined part in any library. Thanks again. On 2015-01-08 03:53, Eric Smith wrote: Links: ------ [1] http://www.brouhaha.com/~eric/retrocomputing/pse/pacer/pac-mp-001.pdf