How do computers work? CPU, ROM, RAM, address bus, data bus, control bus, address decoding.

Description :

0:00 The video begins by explaining the role of the CPU in a computer. 0:45 It then covers computer memory and the concept of cell addresses. 1:30 The differences between read‑only memory and random‑access memory are described. 2:25 The BIOS and its operation are introduced. 3:25 The address bus is explained, followed by the control bus and the RD and WR signals at 5:18. 7:16 The data bus is discussed, including how a byte is read from memory. 9:56 Address decoding is covered, with 10:48 showing how memory ICs are decoded into ranges. 11:29 The relationship between addressable space and the number of address bits is examined. 12:33 The decoding of ROM and RAM ICs in a computer is shown. 14:04 The hexadecimal numbering system and its relation to binary are explained. 16:00 The use of address bits for memory decoding is demonstrated. 16:45 CS, OE signals and the Z‑state (tri‑state output) are discussed. 17:35 A decoder is built using an inverter and the A15 line. 18:18 Reading and writing to memory in a computer system are illustrated. 20:46 The concept of contiguous address space and address decoding in real computers is explored. 21:45 Video memory operation is described. 22:39 Input‑output port decoding, including IORQ and MEMRQ signals, is covered. 23:55 Adding an output port to the computer is shown. 25:13 The operation of a 1‑bit port using a D‑type flip‑flop is explained. 26:12 The ISA and PCI buses and device decoding principles are discussed.