An implementation of John C. Scotts 8-bit computer written in typescript.

Specs

• Memory: 256 bytes
• 4x general purpose registers
• 8-bit word-size

Install

npm install

Usage

npm run start

Run tests

npm run test

Instructions

| instruction code | shorthand | description | | :--------------: | :-------: | --------------------------------------------------------------------------------------------------------------- | | 1000 rarb | ADD | Adds contents of ra and rb together, then places result into rb. | | 1001 rarb | SHR | Shifts contents of ra to the right by one bit, then places result the into rb. | | 1010 rarb | SHL | shifts contents of ra to the left by one bit, then places the result into rb. | | 1011 rarb | NOT | Performs a NOT operation between the bytes stored in ra and rb, then places the result into rb. | | 1100 rarb | AND | Performs a AND operation between the bytes stored in ra and rb, then places the result into rb. | | 1101 rarb | OR | Performs a OR operation between the bytes stored in ra and rb, then places the result into rb. | | 1110 rarb | XOR | Performs a XOR operation between the bytes stored in ra and rb, then places the result into rb. | | 1111 rarb | CMP | Compares the bytes stored in ra and rb, discards output byte, places result of comparison in flag register. | | 0000 rarb | LD | Loads contents of ram address stored from ra into rb. | | 0001 rarb | ST | Stores contents of rb into ram address from ra. | | 0010 00rb | DATA | Loads the byte following this instruction into rb. | | 0011 00rb | JMPR | Jump to the address stored in rb. | | 0100 0000 | JMP | Jump to the address indicated in the byte following this instruction. | | 0101 caez | JCAEZ | Jump if any tested flag is on using JMP, else move IAR forward two bytes. | | 0110 0000 | CLF | Clears the flag register. |

Cpu methods

License

This project is MIT licensed.