The Zx Spectrum Ula How To Design A Microcomputer Zx Design Retro Computer Portable [better] < 2026 Update >

The Silicon Alchemist: The ZX Spectrum ULA and the Art of Efficient Design

The ZX Spectrum remains a masterpiece of minimalist engineering. At its heart lies the Uncommitted Logic Array (ULA), a custom chip that defined the machine’s capabilities and its quirks. Designing a modern microcomputer based on this retro architecture requires understanding how to balance 1980s constraints with today’s portable technology. The Silicon Alchemist: The ZX Spectrum ULA and

To capture the ZX soul, you must implement the "Attribute Clash": Resolution: 256 x 192 pixels. 8 colors (with two brightness levels). Keep high-speed signals (HDMI, SDRAM) routed with controlled

. Use a "framebuffer" in your logic to convert the Spectrum’s video signal to digital. 3.7V Li-Po battery with a TP4056 charging module. Path B: The FPGA "Super ULA" This is

6) PCB and mechanical design tips

• Keep high-speed signals (HDMI, SDRAM) routed with controlled impedance; separate FPGA power domains and add decoupling.
• Provide test headers for JTAG/SWD and the Z80 bus for debugging.
• Design keyboard as a matrix with diodes to prevent ghosting; consider a flat membrane keyboard or small mechanical switches for tactile feedback.
• For portability, integrate a battery management solution and thermal considerations for continuous use.

Path B: The FPGA "Super ULA"

This is where the design of the Spectrum truly evolves. Modern retro engineers have replaced the physical Ferranti ULA with an FPGA (Field-Programmable Gate Array).