Ula- How To Design A Microcomputer -zx Design Retro Computer- — The Zx Spectrum

Further reading: Chris Smith’s "The ZX Spectrum ULA: How to Design a Microcomputer" (an actual book) – This article is the executive summary; his book is the masterclass.

Centralize all timing-critical functions into one programmable logic block. This reduces board complexity and component count. Further reading: Chris Smith’s "The ZX Spectrum ULA:

To design your own retro computer, start with the video signal. The Spectrum’s ULA produced a signal. " he said

Altwasser stared at the board. To fix it in hardware would require redesigning the chip, costing months they didn't have. "We don't change the hardware," he said, his voice steady. "We adapt the software." Further reading: Chris Smith’s "The ZX Spectrum ULA: