SCELBI CPU Traces Connected

If anyone ever said that these early micros were simple, they were wrong.

This board, alone, has 27 ICs, compared to the Apple 1’s 57 (including 16 DRAM chips on the Apple). However the complexity is really revealed by the number of vias. The SCELBI CPU board has about 240 versus the Apple 1’s 296.

SCELBI CPU Board

For each replica PCB board layout, I go through 4 main phases. Placing the major components is phase 1. Connecting the traces is phase 2. Next phase of this board will be aligning traces with an image of an original board. The last phase is an exhaustive checking phase. This is only the first of at least five boards I need to layout before I can power up a replica SCELBI.