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

If you want to replicate the magic on an FPGA or CPLD today, here is the functional spec:

To save RAM (and gates on the ULA), the Spectrum famously splits color from pixels. If you want to replicate the magic on

Because original ULAs are no longer manufactured and prone to overheating, the retro community has turned to modern technology to keep the Spectrum alive. The book " The ZX Spectrum ULA: How

Chris Smith’s work is highly regarded for its approach, which involves stripping the chip down to its circuit diagrams. lower assembly cost

The book " The ZX Spectrum ULA: How to Design a Microcomputer

Instead of 50 discrete TTL chips (logic gates, counters, multiplexers), Sinclair paid Ferranti to draw one metal mask. The result: lower parts count, lower assembly cost, and a single chip that could be "fused" to hide your IP.