For those interested in exploring more:
It has:
This limitation caused "attribute clash"—the famous visual artifact where moving characters would change color based on the background grid. Designing a Modern, Portable ZX Spectrum Clone For those interested in exploring more: It has:
To make your microcomputer portable, you'll need to integrate:
Power the entire project using a standard combined with a TP4056 charging circuit. Step 4: Keyboard and Storage Solutions It handled the scanning of the 40-key matrix
It continuously reads the display file in RAM, converts data bytes into pixels, applies attribute colors, and generates composite television timings (PAL/NTSC).
It handled the scanning of the 40-key matrix keyboard, managed the cassette tape input/output lines, and generated audio for the internal beeper speaker. : It handles keyboard scanning, border color control,
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 handles keyboard scanning, border color control, and the "beeper" sound output/input. Designing a Modern Retro Microcomputer
The ULA was the "glue" that held the Spectrum together. In a standard Z80-based system, you would need dozens of discrete logic chips to manage the interface between the CPU and the RAM. The ULA condensed this into one package. Its primary jobs included: