Sign up for the newsletter
*required fields
Your info will be added to our mailing list until you unsubscribe. We solemnly swear to never share it with third parties or send you spam.

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

Modern approach: Write this in VHDL/Verilog for a CPLD or use an RP2040 with PIO state machines.

In a normal microcomputer (like the Apple II), these tasks are split across separate chips. In the Spectrum, the ULA ate them all:

Think of a ULA as a breadboard of unconnected NAND and NOR gates. You, the designer, pay for a metal mask that connects these gates into whatever logic function you need. It is a semi-custom ASIC. For a low-volume product (relative to Commodore), it was perfect.

Vengaboys pattern

Subscribe to

our Venga-letters!

Your info will be added to our mailing list until you unsubscribe. We solemnly swear to never share it with third parties or send you spam.