Original blog post:
http://8times8.eeems.me:81/blog/index.php?thread=7

CBS6000 stands for Cartridge Based System 6000 (KB)
Name is subject to change (when more ram becomes available)

Specs:

• Cpu: MOS6510 @1MHz
  
• Ram: 128KB (at the moment only 52k accessible)
  
• Rom: 8KB cartridges
  
• I/O: 6x bi-directional, 8x Output-only
  

A while ago I picked up an old rotary dial. I wired it up to my 8 bit computer and it works like a charm! Now I can use it as an input device for more complex programs.

Very impressive. There seems to be a decent push towards breadboard electronics projects which is really cool imo.

I just wrote a sound routine for it. It uses lookup tables to get the right delay values.
Every digit on the dial represents a note. It becomes some kind of slow musical instrument

First of all, this is a very cool project, and I salute you for your continuing series of interesting 8-bit/16-bit computer builds. What made you choose this particular architecture, out of curiosity? Finally, a small bit of criticism: speaking from painful experience, debugging your wiring would be much, much neater if you made sure that your wiring was non-overlapping and flat against each breadboard. Rats-nest wiring gives me twitches.

My wire is pretty thick so it won't bend down easily. If I had thinner wire I would have done it your way for sure.

I wish to move this project to either protoboard or a custom pcb eventually.

I made a project page for this computer in my new project database. You will find detailed information and device specifications here once they become available.
http://8times8.eeems.me:81/project/computers/65xx/cbs/

Why, what kind of wire are you using? I generally use 24 gauge for this sort of prototyping on breadboards.

Very nice! I keep meaning to upgrade the projects/products archive on my personal website to be easier to read and navigate, and that looks like a particularly clean one.

I think I use about the same thickness, but the insulation is pretty stiff, so the wire does not bend very well.

Update:
I changed the memory map to accomodate for the new 8k eeprom that holds the bootloader.

8k ROM
4k I/O space
128k RAM (52k of which accessible)

Next I want to make it possible to disable I/O and ROM so the full 64k ram banks are accessible. Bankswitching between ram banks is done using a pin on the built-in I/O port in the CPU.

The bootloader receives data via SPI and executes the program. I have it hooked up to my PC's parallel port, so I can send files directly to the 8 bit computer. This saves a lot of time! (I used to write data to a cartridge and then I had to insert it in the computer)