Full Adder from Relays: Sum, Carry-In, and Carry-Out
In the previous post, we built the half adder: XOR for the sum bit, AND for the carry bit. Two inputs in, two outputs out — a clean circuit that correctly...
Tag
Computer arithmetic
A collection of 3 posts
BCD (Binary-Coded Decimal): Fundamentals Explained
TL;DR: Binary-coded decimal (BCD) stores each decimal digit 0–9 in a 4-bit nibble, leaving 1010–1111 unused. A BCD digit adder applies a +6 correction when...
How an ALU Works: Arithmetic Logic Unit from Gates
TL;DR: A small ALU is a combinational datapath: candidate arithmetic, logic, and shift functions operate on the same input words, and a multiplexer selects the visible result. The design...