There are 80 wires to the eight output ports on a SCELBI, and 54 wires to the six input ports. All wires must be cut to length, stripped and soldered by hand. This wiring is, by far, the most tedious and time consuming single task involved in building a reproduction SCELBI. When I wired the I/O ports on my SCELBI 8H, I did it in one marathon session that took almost an entire day. For my 8B, I’m not in so much of a hurry and so far, have had 3 shorter sessions and have 56 of the 134 wires connected. The connected wires are all the ground wires for both input and output. I also have 6 bits out of the 8 bits of the output port bussed together, but not connected to the backplane. For connecting the output data bus, I found I could cut and strip a batch of equal length wires, then solder them between connectors.

SCELBI 8B I/O Port Wiring in Progress

The blue painters tape is there to protect the edges of the enclosure while the system is being constructed. I think another three or four sessions and I’ll finally have the wiring task done.