Hacked Gadgets Forum

February 19, 2014

Nibbler – Home Made CPU

at 11:39 am. Filed under Complex Hacks, DIY Hacks

 Nibbler - Home Made CPU


Steve from the Big Mess o’ Wires blog has built a Home Made CPU called the Nibbler. Why the name? Because it is a 4 bit CPU (half of a byte is a nibble). Other than a creative name the project is quite an undertaking, it is built using 7400 logic all wire wrapped up for easy debugging. 🙂

“Some specs:

  • 4 bit custom-made CPU
  • 12 bit addressing, 4K address space size
  • Harvard architecture – separate program and data memory spaces
  • 2 MHz clock speed, 2 clocks per instruction = 1 million instructions/sec
  • Thirteen 7400-series chips in the CPU data and control paths
  • Two 28C16 EEPROMs store microcode for generating internal control signals
  • 4K x 4 SRAM (CY7C168A)
  • 28C64 EEPROM stores programs
  • Four pushbutton inputs
  • 16 x 2 character LCD
  • Audio speaker
  • About 100 mA current draw at 5V”


Nibbler - Home Made CPU_3


Nibbler - Home Made CPU_2