Relay Computer

My journey in constructing an 8 bit relay computer from scratch ... made from of a ton of solder, wires, lights, relays, sweat, tears, swearing and money.

Control Summary

The computer is controlled by a series of instructions held in memory (a computer program) that are loaded into the instruction register one at a time and executed. The execution of an instruction is performed by running a clock signal through a sequencer which produces a series of pulses. These pulses are then used to operate the control lines of the computer at the right time and in the right order appropriate for the current instruction. Every time an instruction is performed a program counter is incremented such that the counter points at the next instruction in memory. Depending on the instruction being performed though the program counter may jump to another point in the program entirely.

  Design Construction Testing
(in general)
    MOV-8, ALU & SETAB
Control Unit Overview
MOV-8, ALU & SETAB: (Part1, Part2)
Fetch and Increment
Fetch and Increment
Fetch and Increment
Decoder MOV-8, ALU & SETAB MOV-8, ALU & SETAB  
Memory Design (Part1, Part2) Construction (Part1, Part2) Testing
Incrementer 1-bit Half Adder
16-bit Half Adder
Full Design
Construction (Part1, Part2) Testing
Sequencer Overview
8-cycle FSM
Pulses C, D and E
8-cycle FSM