The Zx Spectrum Ula How To Design A Microcomputer Pdf 57l -

The book methodically breaks down the computer into functional blocks, explaining how the ULA orchestrates them.

"Figure 57L: Vertical Sync Generation. The ULA contains a nine-bit vertical line counter. Upon reaching line 312 (PAL standard), the reset logic triggers a vertical blanking period. Designers must ensure that the CPU’s NMI (Non-Maskable Interrupt) is asserted exactly during the flyback period to permit tape loading routines." The Zx Spectrum Ula How To Design A Microcomputer Pdf 57l

: Using the research from this book, Chris Smith developed the Harlequin , a completely functional 100% compatible ZX Spectrum clone built entirely out of discrete, off-the-shelf logic chips instead of a ULA. The book methodically breaks down the computer into