RAM: the forgotten history (2024)
2 days ago
- Early electronic memory used relays, which had slow switching speeds and were a dead end for main memory.
- Vacuum tube SR latches, invented by Eccles and Jordan, formed the basis for modern SRAM but were costly and power-hungry.
- Dynamic memories like capacitor drums (Atanasoff-Berry), delay lines (mercury, torsion), and cathode-ray tubes (Williams/Selectron) offered cheaper storage with periodic refresh.
- Magnetic core memory dominated from the 1950s to 1970s, offering speed and non-volatility through ferrite beads with threshold magnetization.
- The first single-chip SRAM (Intel 3101, 64 bits) and DRAM (Intel 1103, 1 kilobit) marked the shift to integrated circuit memories, eventually replacing core.
- Modern DRAM uses capacitors on silicon, requiring less space than SRAM but slower and needing refresh; SRAM remains in CPUs for high-speed cache.