The Complete Mnemonimov Instruction Set Reference: Mastering the 32-Bit Fantasy Console

If you want to build games, operating systems, or rendering engines in Reverie Foundry’s 2026 low-level sandbox, you need a definitive Mnemonimov instruction set reference. The game drops you into a 32-bit register-based virtual machine with zero hand-holding—no tutorials, no wizards, just you and a retro monochrome screen. To tame this fantasy console, you must understand its RISC-style memory access, floating-point operations, and vector instructions at a molecular level. This guide strips away the guesswork, providing a complete, heavily detailed breakdown of every assembly command, ABI convention, and system call available in the game. Forget the shallow community wikis; this is the ownership-grade manual for writing highly optimized code.

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Mnemonimov (pronounced nee-mo-ni-move) is not a guided learning tool. Like a 3D editor won't teach you how to model, this game will not teach you programming logic. You are expected to read the manual, write code, run it, debug it, and repeat.

Core Architecture in the Mnemonimov Instruction Set Reference

Before writing a single line of assembly, you must understand the hardware constraints of the virtual machine. Mnemonimov utilizes a custom 32-bit RISC (Reduced Instruction Set Computer) architecture. This means memory access is strictly separated from arithmetic operations; you cannot perform math directly on memory addresses. You must load data into a register, process it, and store it back.

The CPU features 16 core 32-bit registers (R0 through R15), alongside a dedicated Flags Register (FR) that tracks the state of the last ALU operation (Zero, Carry, Overflow, Negative). Adhering to the game's Application Binary Interface (ABI) conventions is critical when writing modular code or macros.

The Register Map

Infographic: Mnemonimov 32-bit VM register architectureauto_awesomeGenerate one like thisarrow_forward

Because the game features large memory limits with no restrictions on code length, you have ample room to build complex call stacks. However, failing to push and pop R4-R11 inside your subroutines will corrupt your game state and lead to agonizing sessions in the integrated debugger.

Data Movement & Memory Operations

Data movement instructions are the lifeblood of your program. Since Mnemonimov uses a RISC-style load/store architecture, these are the only instructions that interact directly with the virtual RAM.

When rendering graphics to the 320x240 monochrome screen, you will constantly use LDR and STR to manipulate the memory-mapped framebuffer. Memory alignment is strictly enforced; attempting to load a 32-bit word from an unaligned address (one not divisible by 4) will trigger a hardware fault in the debugger.

Arithmetic, Logic, and Vector Instructions

The Arithmetic Logic Unit (ALU) handles standard integer math, bitwise operations, and—crucially for rendering—vector processing.

Standard Integer Math

Bitwise Logic

Bitwise instructions are essential for masking inputs and packing data.

Vector Instructions (SIMD)

One of the most powerful features in the Mnemonimov sandbox is its native vector instructions. Because the display is a 320x240 monochrome screen, a single 32-bit register can hold four 8-bit pixel values (or 32 1-bit pixels, depending on your custom engine's design). Vector instructions allow you to process these chunks simultaneously (Single Instruction, Multiple Data).

Annotated Diagram: Vector pixel packing in Mnemonimovauto_awesomeGenerate one like thisarrow_forward

• VADD VRd, VRs1, VRs2: Performs four parallel 8-bit additions within the 32-bit registers.
• VSUB VRd, VRs1, VRs2: Performs four parallel 8-bit subtractions.
• VMUL VRd, VRs1, VRs2: Performs four parallel 8-bit multiplications.

If you want your custom game to run at a locked 60 Hz, you cannot afford to process pixels one by one. Using VADD to shift the position of four pixels in a single CPU cycle is the meta for achieving high-performance rendering in this fantasy console.

Floating-Point Operations

Unlike actual retro 8-bit consoles, Reverie Foundry equipped this VM with an FPU (Floating-Point Unit). This allows for complex physics simulations and 3D rendering engines.

• FADD, FSUB, FMUL, FDIV: Standard IEEE 754 32-bit floating-point arithmetic.
• ITOF Rd, Rs: Converts an integer in Rs to a float in Rd.
• FTOI Rd, Rs: Converts a float in Rs to an integer in Rd (truncates decimal).

Control Flow and Branching

Linear execution only gets you so far. To build game loops, state machines, and conditional logic, you must manipulate the Program Counter (R15).

Control flow begins with the CMP (Compare) instruction: CMP Rs1, Rs2. This subtracts Rs2 from Rs1 but discards the result, updating only the Flags Register (FR). You then follow it with a conditional branch:

• BEQ label: Branch if Equal (Z flag = 1).
• BNE label: Branch if Not Equal (Z flag = 0).
• BGT label: Branch if Greater Than.
• BLT label: Branch if Less Than.
• JMP label: Unconditional jump.

For subroutines, use CALL label. This automatically pushes the address of the next instruction into the Link Register (R14) and jumps to the label. To return, simply use RET, which moves the value from R14 back into the Program Counter (R15).

System Calls and the Mnemonimov Instruction Set Reference

Your assembly code exists in a vacuum until you invoke a SYSCALL. System calls act as the bridge between your raw math and the fantasy console's hardware—handling rendering, input, and persistent memory storage.

Analysis Report Poster: Mnemonimov system call memory mapauto_awesomeGenerate one like thisarrow_forward

To execute a system call, load the required arguments into R0 through R3, then issue the SYSCALL <imm> instruction.

Output and Debugging

• SYSCALL 0x01 (Terminal Output): Prints a null-terminated string to the integrated code editor's terminal. R0 must contain the memory address of the string. Invaluable for printing variable states without stepping through the debugger.

Hardware Rendering

Mnemonimov does not have a sprite editor or a tilemap engine. You must write your graphics directly to the memory-mapped framebuffer, then tell the hardware to draw it.

• SYSCALL 0x20 (Flush Framebuffer): Pushes the current state of the memory-mapped video RAM to the 320x240 monochrome screen. You should call this exactly once at the end of your main game loop to maintain a smooth 60 Hz refresh rate.
• SYSCALL 0x21 (Clear Framebuffer): Instantly zeroes out the video RAM. Faster than writing a loop to STR zeroes across the memory block.

User Input

• SYSCALL 0x10 (Poll Gamepad): Reads the current state of the virtual controller. The result is returned in R0 as a bitmask (e.g., Bit 0 = Up, Bit 1 = Down, Bit 4 = Action A). Use bitwise AND to check specific button states.

Persistent Storage

• SYSCALL 0x30 (Read Save Data): Loads data from the persistent memory storage into RAM. R0 takes the destination RAM address, and R1 takes the number of bytes to read.
• SYSCALL 0x31 (Write Save Data): Writes data from RAM to persistent storage, allowing players to save their progress across runs.

Advanced Techniques Using the Mnemonimov Instruction Set Reference

Writing raw assembly can quickly become unmanageable. The integrated code editor provides several directives to structure large programs cleanly.

Labels and Bookmarks: Instead of calculating raw memory addresses for your jumps, use string labels (e.g., Player_Update:). The assembler calculates the exact PC offset at compile time. Bookmarks allow you to quickly navigate between major subsystems (like Physics, Rendering, and Input) within the editor.

Constants (.EQU): Avoid magic numbers. Define constants at the top of your file: .EQU SCREEN_WIDTH 320 .EQU SCREEN_HEIGHT 240 This makes your code highly readable and easier to refactor if you decide to implement a virtual camera system.

External Assets (.INCBIN): The game supports referencing external assets. You can use the .INCBIN directive to load binary files—such as pre-calculated sine wave tables or raw pixel art data—directly into your program's memory space at compile time.

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When a fault occurs, lean heavily on the integrated debugger. Do not rely solely on SYSCALL 0x01. Set breakpoints on critical CALL instructions, step through the execution cycle by cycle, and watch how your R4-R11 registers mutate. The debugger's detailed error reporting will usually catch stack overflows and unaligned memory access before they crash the VM.

Frequently Asked Questions (FAQ)

Does Mnemonimov use real-world ARM or x86 assembly? No. While heavily inspired by standard RISC architectures (like early ARM chips), it uses a custom 32-bit instruction set designed specifically for this fantasy console. This removes the bloated legacy instructions of real hardware while preserving the authentic low-level programming experience.

How do I render sprites if there is no sprite editor? You must calculate the memory address of the specific pixel in the framebuffer, use bitwise logic to construct the sprite, write it to memory using STR, and invoke SYSCALL 0x20 to flush the buffer to the screen.

Is there a limit to how long my code can be? Mnemonimov features massive memory limits with no arbitrary restrictions on code length or execution speed. Your only bottleneck is the 60 Hz rendering window; if your game loop takes too many CPU cycles, your frame rate will drop.

Can I export my creations as standalone games? Currently, creations live inside the Mnemonimov sandbox. Players must own the game to load and run your assembly projects via the command-line interface.

Building a game from scratch in assembly is a daunting task, but mastering the architecture provides an unparalleled sense of ownership over your code. Keep this reference handy, respect the ABI conventions, and let the hardware do the heavy lifting.

Sources

• Reverie Foundry Official Documentation
• Mnemonimov Integrated Technical Reference Manual
• Steam Store Architecture Specifications