Breadboard Computer

I've been following Ben Eaters series on building an 8bit BreadBoard computer.

Here is my attempt at replicating the same.


https://cdn.shopify.com/s/files/1/0089/0647/3536/products/4-output-control_550x825.jpg?v=1544158171


Chips used


Modules


  • Key

    • B4 - 4but Bus

    • B8 - 8bit Bus

    • S - Signal

    • I - In

    • O - Out

    • IO - In/Out


  • Clock

    • 555

    • 74HC00 -Quad 2-input NAND gate

    • IO

      • "C" Clock (SO)

      • "H" Halt (SI) - Stops the clock from running

  • Program Counter

    • 74HC245 - Octal 3-state buffer

    • 74HC161 - 4 bit binary counter

    • IO

      • "R" Reset (SI) - Resets the Program counter register to zero.

      • "PC" Program Counter (B4IO)

      • "PCA" Program Counter Advance (SI) - Advances the program counter, on next clock.

      • "PCE" Program Counter Enable (SI) - Enables the A register output onto the bus.

      • "PCJ" Program Counter Jump (SI) - Reads a new value for the program counter from the bus, on the next clock

  • Register A

    • 74HC245 - Octal 3-state buffer

    • 74HC173 - Quad Flip-Flop

    • IO

      • "R" Reset (SI) - Resets the A register to zero.

      • "AR" Register A (B8IO)

      • "ARE" Register A Enable (SI) - Enables the A register output onto the bus

      • "ARR" Register A Read (SI) - Reads a new value for the A register from the bus, on the next clock

  • Register B

  • Output

    • 74HC595 - 8bit shift register

  • Address Register

  • RAM

  • Ram IN

  • Instruction Decoder

April 2017

The clock

The first register

May 2017

Its got more registers and some memory

June 2017

Getting big, so has a backplate.

Now with an ALM and output module.