# Koopman TOY CPU Interpreter
This is a CPU interpreter, based on the specification of Phil Koopmans paper: [Microcoded Versus Hard-wired Control](https://users.ece.cmu.edu/~koopman/misc/byte87a.pdf).
For more details, have a look at /doc or press `toy_cpu -h` (for help) or `toy_cpu -a` (for cpu architecture overview)
## Build
The project can be built by using `make`.
You do not have to pay attention to external dependencies. This is standard C99 code.
## Usage
Transfer the RAM content to the machine via a text file.
The program call is: `toy_cpu` SOURCE.toy
The following is the specification for a 16 BIT machine word. With it, you can create the RAM content.
(Do not forget: this is a pure John von Neumann architecture, data and program are in the same memory)
OP_Code 0 (0000b): STORE<12 BIT ADDRESS>
OP_Code 1 (0001b): LOAD <12 BIT ADDRESS>
OP_Code 2 (0010b): JMPZ <12 BIT ADDRESS>
OP_Code 3 (0011b): ADD <12 BIT ADDRESS>
OP_Code 4 (0100b): SUB <12 BIT ADDRESS>
OP_Code 5 (0101b): OR <12 BIT ADDRESS>
OP_Code 6 (0110b): AND <12 BIT ADDRESS>
OP_Code 7 (0111b): XOR <12 BIT ADDRESS>
OP_Code 8 (1000b): NOT <12 BIT undefined>
OP_Code 9 (1001b): INC <12 BIT undefined>
OP_Code 10 (1010b): DEC <12 BIT undefined>
OP_Code 11 (1011b): ZERO <12 BIT undefined>
OP_Code 12 (1100b): NOP <12 BIT undefined>
OP_Code 13 (1101b): NOP <12 BIT undefined>
OP_Code 14 (1110b): NOP <12 BIT undefined>
OP_Code 15 (1111b): NOP <12 BIT undefined>
BIT |15 14 13 12|11 10 9 8 7 6 5 4 3 2 1 0|
---------------------------------------
| OP-CODE | ADDRESS |
---------------------------------------
This machine has the following registers:
* 16 BIT Instruction Register (4 BIT OP, 12 BIT Addr)
* 16 BIT Accumulator
* 12 BIT Program Counter
Example: 0001000000001010 at RAM position 0
0001 means: LOAD the content of ADDRESS 000000001010 into the ACCU
## Licence
This program by Michael Krause is licenced under the terms of the [GPLv3](https://www.gnu.org/licenses/gpl-3.0.de.html).