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Zusie – My Relay Computer
About Zusie I amuse myself by constructing a computer almost entirely out of relays. Relays were used to construct computers well before vacuum tubes, transistors or integrated circuits were feasible for the task.
In addition to constituting an important historical link between the mechanical and electronic computers, relays are especially fun to work with since they subscribe to Lenz' law, i.e. generate lots of EMF and flyback current that make for all sorts of interesting interference in places you couldn't even guess. 8-bit data bus and 16-bit address bus 3 x 8-bit accumulator registers, 2 x 12-bit registers (for index, addresses and jumps) 64k solid state memory, holding heap, stack and program 12-bit program counter and 12-bit stack pointer ALU capable of not, and, or, xor, add, increment, decrement, shift, and indirectly, subtraction Writable microprogram stored in solid-state device for sequencing Assembler and Microassembler running in DOS and communicating with Zusie over parallel port.
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