Close

Added RAM and ROM module

A project log for 8 Bit Breadboard CPU

A home-brew 8 bit Microprocessor built on a breadboard 64K Address Space, IRQ, and DMA 16 Bit Stack Pointer, 4 8 bit Registers or 2 16 bit

2-Zons2-Zons 02/10/2019 at 04:242 Comments

I'm back from my little vacation in Vegas and have been busy building.  I bought a sheet of 1/4" acrylic to mount all the boards together.  I was tired of trying to clip them together with wires or headers.  It's working nicely.  I wanted to start running all my control lines into their positions so I can get rid of all those big loopy wires.  I couldn't do that until I had a place for them all to go (the empty board at the bottom).  I have room for another column of breadboards on the left side of the data bus.

I finished the RAM / ROM module and tested it.  I used a ZIF socket for the 32K ROM chip to make reprogramming quick.  I have more of them for the microcode ROM's.   The address bus is removed in the picture as well as the data bus connections to the RAM ROM module.  The RAM / ROM module is technically "external" to the CPU and my DI control line would be the R/W output.  The DI control line would control the tri-state buffers between the internal and external data bus.

Discussions

Dave's Dev Lab wrote 02/10/2019 at 18:32 point

looking really good!

  Are you sure? yes | no

Amos wrote 02/10/2019 at 05:13 point

Wow! Looking nice! 8^)

  Are you sure? yes | no