Here is the design lesson: Every optimization has a consequence. To save memory, the ULA used a "color attribute" system. Every 8x8 pixel block shared foreground color and one background color.
The book " The ZX Spectrum ULA: How to Design a Microcomputer Here is the design lesson: Every optimization has
The ZX Spectrum ULA: How to Design a Microcomputer is a comprehensive technical book by , published by ZX Design Technology and Media . It serves as a deep-dive case study into the Sinclair ZX Spectrum's custom "heart"—the Ferranti Uncommitted Logic Array (ULA). Feature Overview Here is the design lesson: Every optimization has