Memory Expansion for ZX Spectrum and Compatible Computers

This section is dedicated to hardware solutions for expanding the memory capacity of ZX Spectrum computers and their many compatible clones. It contains schematics, technical documentation, and practical guides for upgrading systems with additional RAM, cache memory, and modern memory modules.

The articles cover a wide range of memory expansion projects, from classic 128 KB and 512 KB upgrades to advanced configurations featuring 1 MB and even 4 MB of RAM. Detailed solutions are provided for Pentagon, Scorpion, Profi, Byte, Baltika, Taganrog-128, Tashkent-128, Synthesis-2, Lvov, and other Spectrum-compatible computers.

Particular attention is given to the use of standard SIMM memory modules, memory banking techniques, address decoding logic, port #FD implementation, and alternative memory management schemes. The collection includes both universal expansion designs and model-specific hardware modifications.

A dedicated group of articles focuses on cache memory systems, including static RAM implementations, battery-backed cache solutions, performance optimization techniques, and practical considerations for high-speed memory operation.

Additional topics include shadow ROM designs, alternative memory controllers, RAM chip upgrades, memory expansion boards with integrated AY sound chips, and comparisons of memory architectures used in different Spectrum-compatible systems.