Month August 2013

Nibbler simulator

Nibbler Software Tools

During development of the Nibbler CPU, I’ve created several software tools to help make my life easier. Some of these have been nearly as interesting as the CPU itself! While professionally I work with C++ or Java, for my personal…

Nibbler instruction encoding

Programming the 4-Bit CPU

Instructions for the Nibbler 4-bit CPU come in two types: immediate and addressed. Both types begin with 4 bits of instruction opcode, to identify the specific instruction. Immediate instructions like ADDI include a 4-bit operand value embedded in the instruction,…

Nibbler architecture diagram

Hello Nibbler!

Say hello to Nibbler, the 4-bit homemade CPU! Ever since I built BMOW1, people have written to me asking how to make their own homebrew computers. BMOW is a complex design that can be difficult to comprehend, so I decided…