The classic Spectrum keyboard is a membrane matrix that feels uniquely rubbery. For a modern portable computer:
This comprehensive technical guide explores how the original ZX Spectrum ULA functioned and details how to design a portable, modern microcomputer utilizing "ZX Design" principles. Anatomy of the ZX Spectrum ULA
The ZX Spectrum ULA (Uncommitted Logic Array) is a remarkable chip that played a crucial role in the design of the iconic Sinclair ZX Spectrum microcomputer. Released in 1982, the ZX Spectrum became a bestseller, and its success can be attributed in part to the innovative design of the ULA. This review explores the ULA's design, its significance in the ZX Spectrum, and provides insights into designing a microcomputer. The classic Spectrum keyboard is a membrane matrix
+-----------------------------------------------------------+ | PORTABLE POWER SOURCE | +-----------------------------------------------------------+ | v +------------------+ +---------------+ +--------+ | Z80 CPU / MCU | <---> | MODERN ULA | <---> | DISPLAY| | (Core Processor)| | (CPLD / FPGA) | | (LCD) | +------------------+ +---------------+ +--------+ ^ | +---------------------------------+-------------------------+ | INPUT & STORAGE (Keyboard / SD Card) | +-----------------------------------------------------------+ 1. Replicating the ULA (The Glue Logic)
Small 3.5-inch TFT LCD screens can be driven directly via SPI or parallel interfaces from your microcontroller. Released in 1982, the ZX Spectrum became a
Recreating the ZX Spectrum experience hinges on reproducing both function and timing. Using an FPGA to implement a modern ULA lets you preserve the machine’s behavioral quirks (what made the Spectrum special) while adding modern conveniences for portability. Start with a focused FPGA video/DRAM prototype, iterate with a simple ROM and Z80 core, and build outward—balancing authenticity and usability to produce a compact, lovable retro microcomputer.
When designing a retro computer or portable device, consider the following: Replicating the ULA (The Glue Logic) Small 3
An EPROM can be used as a look-up table to generate the complex timing signals required for video output. Design Challenge: