pbohun / corgi64

Corgi64: Simulated Computer

Welcome!

What if you had a computer that had the simplicity of the Commodore 64 with the power of more modern systems? What if you had a simulation of a cpu, monitor, keyboard and mouse controller, etc. that you could easily read through and modify to learn more about computers? What if the simulated computer was simple enough that individuals could take on other learning projects far more easily, like building their own operating system?

That's the idea and purpose behind the Corgi64 project, to provide a simple, modular, and compact simulated computer system that allows people to learn more about computers.

NOTE: This is a work in progress, it is not yet finished or fully functioning yet. Please look at the videos linked below to take a look at the progress.

I have a video series detailing my efforts writing Corgi64: https://www.youtube.com/watch?v=EhO5W6y3BWc&list=PLSiFUSQSRYAND5ETcWAkiD5tBxM-kZGLD

System Requirements

Because I wanted this system to be as simple as possible I've only targeted one type of system, Windows 10 on x64 processors. If you are programming savvy, feel free to port it to other systems.

To compile Corgi64, you'll need the c++ compiler offered by Microsoft Visual Studio. You can acquire a free version here: https://www.visualstudio.com/vs/community/

Alternatively, Corgi64 should be able to compile with gcc offered through MinGW or Cygwin.

Compiling and Running

To compile Corgi64, run the following command within the main directory:
build.bat

To run Corgi64, run the following command:
bin\main.exe

corgi64's Issues

Unset Zero Flag

I've looked at the code and noticed that you never actually unset the zero flag in the event that a number is greater than or less than zero. You set/unset the negative flag, but shouldn't the zero-flag also be unset?

[instruction set] problem with accessing memory

IMO there is ambiguity with the STA, STB, and STC instructions:
Does the register contain the value or the address ?

Maybe there should also be an instruction to store a value in B to memory at address A or something similar. (Or is there a way to do that already?)