HEE HOO VM

Very stupid, unenlightened, primitive machine. hee hoo

Bare essentials to be turing complete. Just some registers and a memory block.

Installation

Requires a Rust toolchain, 1.88 or newer (see rustup.rs). Clone the repo, then build with Cargo:

git clone <repo-url> heehoo-vm
cd heehoo-vm
cargo build

Usage

cargo run

Binary file format

All multi-byte numbers are little-endian.

Offset	Size (bytes)	Field
0	10	Magic text: ASCII markiplier
10	1	Version number
11	2	Instruction section size, in bytes
13	2	Data section size, in bytes
15	2	Start instruction pointer
17	inst size	Instructions, one 16-bit word each
...	data size	Initial data memory (loaded from address 0)

For example, a program that runs INIT 0 10 then HALT:

6D 61 72 6B 69 70 6C 69 65 72   "markiplier"
00                              version 0
04 00                           4 bytes of instructions
00 00                           0 bytes of data
00 00                           start at instruction 0
0A 10                           0x100A = 0001 00 0000001010 = INIT 0 10
00 00                           0x0000 = 0000 00 0000000000 = HALT

System Architecture

16-bit architecture. Memory addressed by 10-bits (1024 memory cells, each 16-bit words). Separate instruction memory addressed by 16-bit instruction pointer (65536 cells). 4 General Purpose Registers.

Memory

Instruction Set

Instruction Layout

Op   Arg 1  Arg 2
0000 00     0000000000

Instruction	Opcode	Description
HALT	0000	Stop execution of code
INIT reg val	0001	Initialize register reg to value val
LOAD reg adr	0010	Load value in memory address adr to register reg
SAVE reg adr	0011	Save value in register reg to memory address adr
MOVE rA rB	0100	Move value in register rB to register rA †
WRITE reg	0101	Output the value of register reg to the terminal
READ reg	0110	Read a value from the terminal into register reg
ADD rA rB	0111	Add value in register rB to value in register rA. Store result in rA †
AND rA rB	1000	Bitwise and value in register rB from value in register rA. Store result in rA †
OR rA rB	1001	Bitwise or value in register rB from value in register rA. Store result in rA †
NOT reg	1010	Bitwise not value in register reg Store result in reg
JUMP adr	1011	Jump to instruction at adr
JPZR adr	1100	Jump to instruction at adr if last operation resulted in zero
JPOV adr	1101	Jump to instruction at adr if last operation resulted in an overflow

† Operation does not delete/overwrite value in other argument registers