The Zx Spectrum Ula How To Design A Microcomputer Zx Design Retro Computer Portable Jun 2026

Think of a ULA as a "semi-custom" chip. It came from the factory with a grid of logic gates (NAND and NOR gates) already printed, but unconnected. An engineer would then design the connections between these gates to create specific functions.

Are you currently working on a Spectrum portable build? Are you team "Original Hardware" or team "FPGA"? Let us know in the comments! Think of a ULA as a "semi-custom" chip

For a portable device, is the gold standard. The ULA’s parallel nature (video, CPU arbitration, DRAM refresh happening simultaneously) maps perfectly onto an FPGA’s hardware logic blocks. Are you currently working on a Spectrum portable build

Raspberry Pi Pico (RP2040) can bit-bang a Spectrum via software emulation of the ULA. For a portable device, is the gold standard

. As the words scrolled infinitely on his handheld creation, he realized he hadn't just built a computer; he’d bottled lightning. specific logic equations used to replicate the ULA, or should we look at the PCB layout requirements for a portable build?