(Name definitely not final)
I've come up with all the major ideas to put this emulator together and make it work and all I need to do is do that. The emulator will be configurable with an external config file which has it's own script for more functionality such as scripting for adding emulated peripherals or defining cpu hardware which is unique in some processors(?). Here's how it'll work:
1. Basic program setup stuff (vars, defs, etc.).
2. Load config file and configure the emulator according to the scripts if it exists. If it doesn't create a new config based on default values and continue with the default values.
3. Load the config-designated INSTRSET.TXT file (this contains all the instructions the cpu will have available).
4. Load the config-designated DRIVE.DAT file (virtual disk storage).
5. Load the ROM with the config-designated BIOS.DAT file (an optional machine code script which manages the hardware during startup and loads an operating system from disk, can be reconfigured for a custom BIOS or replaced with a disk-based one, if you're weird).
6. Begin the fetch/decode/execute cycle.
7. Because there are no instructions in the RAM the first instructions from the ROM are loaded into the RAM. The instructions then take over and load more instructions from the ROM which perform system checks and load any OS from the disk. The default BIOS will simply halt and display an error if there is no OS to load to the RAM.
8. Full control is given to the user/OS once all the checks pass.
The configuration file will make this emulator very customizable. The RAM size, ROM size, bit width, clock speed, drive file name, BIOS file name, and instruction set file name can all be changed. Care will have to be taken to be sure the chosen bit width can support the chosen instruction set. The fetch/decode/execute cycle will remain as an not configurable core feature. The instruction set will be loaded into a string array which is compared with the fetched byte(s) during the decode section of the cycle. Custom configuration scripts in the config might be a feature to control even more things but what things I'm not sure, maybe to define peripheral devices and ways to load additional drives? Ideas and improvement ideas for the emulator I'm about to code are what this thread's for.
