Planning the logic design for one single bit
Input for every bit computes from bit x, bit y and the carry c-1 from the last bit. I could have saved a few relays by ignoring the c input on the LSB (least significant bit), because there can't be a carryover c-1, but I didn't. Also I'm not using the most efficient design possible with the relays I choose. These are switch relays, but I only use that functionality on the XOR-gates. My focus is a comprehensible design, not the most efficient one.
First batch of components arriving...
The relays I use
Leds, switches, desoldering pump
The switches for turning the single bits on and off. Found out later that I only ordered 4 switches instead of 8... 5€ shipping for 3€ switches...
Logic testing of the first OR-gate. Works like a charm.
Control unit layouting...
That's the point I realise I'm four switches short...
I cut off my screwdriver to put it in the drill. So I got the remaining plates processed pretty fast.
More pictures and description will follow soon...
Great looking build and hope there will be updates or more projects soon :-)