The continuity continues...

Half way through checking every pin of the CPU socket for bad joints, broken tracks etc. as per the Issue 4a/b Schematic at Retroisle - no problems so far apart from the following...

Either the schematic contains 2 glaring errors so far, or my brains do. CPU Pin 2 goes pin 12 of IC3 on the schematic but is connected to pin 2 on my board, as it does in the Issue 3b Schematic. Also, pin 5 of the CPU socket is shown as connected to pin 27 of the ULA in the 4a/b schematic, same in the 3b schematic, but on my board it connects to pin 37 on the ULA like in the Issue 5 Schematic.

I'm not going to mention it elsewhere yet in case I'm wrong, or have the short from hell as a result of my dodgy soldering, or both... :).

So, 20 pins (1 to 20) later and half my optimism gone, everything is as it should be so lets hope the next 20 reveal the problem - otherwise I'm stuck.

EDIT: It also looks like I've found another error, if I am right then this is the same for the 2b, 3b and 4a schematics - pins 4 & 5 of IC24 are reversed and only seems to be correct on the Swedish Issue 3 schematic I found.