If you want to understand the Spectrum’s specific internal hardware architecture, the repository on GitHub provides an extremely detailed, structured breakdown of the Z80, the ULA timing, and the machine's inner workings.
To build a modern portable "ZX-like" computer, you don't need to source a vintage ULA. Instead, you must understand its functions and replicate or re-imagine them using modern hardware.
Understanding the ULA has allowed the global retrocomputing community to keep the ZX Spectrum alive indefinitely. Projects like the have taken the reverse-engineered ULA logic and expanded upon it, adding enhanced graphics modes, faster CPU speeds, and SD card support—all while maintaining 100% backward compatibility with the original 1982 software. If you want to understand the Spectrum’s specific
user wants a long, in-depth article about the ZX Spectrum's ULA chip and designing a retro portable microcomputer. The keyword is long but the core topics are ULA design, ZX Spectrum architecture, retro computing, and portable builds. I need to cover technical details, design principles, and practical projects.
The simplest path is the PicoZX route: a Raspberry Pi Pico running an emulator, paired with a 2.8-inch IPS display (ST7789V, 280×240 resolution works well). For greater authenticity, use an FPGA implementation (such as the ZX Uno) that replicates the original ULA's behaviour in hardware. For maximum historical challenge, source original Z80 and ULA chips from vintage Spectrums. Understanding the ULA has allowed the global retrocomputing
For those who prefer programming hardware to soldering wires, an FPGA (Field-Programmable Gate Array) is the best tool. An FPGA allows you to design the digital logic of the entire computer at a gate level.
It manages the timing for the 256x192 pixel display, converting ULA pixel data and attributes into a TV signal. The keyword is long but the core topics
:
:
Managing access to the lower 16KB of RAM between the CPU and the video display generator.