https://github.com/qalle2/nes-bf
Brainfuck interpreter (NES)
https://github.com/qalle2/nes-bf
6502 asm6 assembly brainfuck homebrew nes
Last synced: 2 months ago
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Brainfuck interpreter (NES)
- Host: GitHub
- URL: https://github.com/qalle2/nes-bf
- Owner: qalle2
- License: gpl-3.0
- Created: 2022-05-21T16:14:53.000Z (about 4 years ago)
- Default Branch: main
- Last Pushed: 2023-10-05T01:36:59.000Z (over 2 years ago)
- Last Synced: 2023-10-05T11:07:03.721Z (over 2 years ago)
- Topics: 6502, asm6, assembly, brainfuck, homebrew, nes
- Language: Assembly
- Homepage:
- Size: 198 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Qalle's Brainfuck
A Brainfuck interpreter for the [NES](https://en.wikipedia.org/wiki/Nintendo_Entertainment_System).
Table of contents:
* [List of files](#list-of-files)
* [Features](#features)
* [Technical info](#technical-info)
* [How to use](#how-to-use)
* [Edit mode](#edit-mode)
* [Run mode](#run-mode)
* [Character set](#character-set)
* [References](#references)
## List of files
* `*.bf`: long Brainfuck programs
* `assemble.sh`: a Linux script that assembles the program (warning: deletes files)
* `bf.asm`: source code (assembles with [ASM6](https://www.romhacking.net/utilities/674/))
* `bf.nes.gz`: the assembled program (iNES format, gzip compressed)
* `chr.bin.gz`: CHR ROM data (gzip compressed)
* `chr.png`: CHR ROM data as an image (can be encoded with `nes_chr_encode.py` in my [NES utilities](https://github.com/qalle2/nes-util))
* `examples.txt`: short Brainfuck programs
* `movies.tar.gz`: FCEUX movie files that enter a Brainfuck program into the NES program
* `snap*.png`: screenshots
* `txt2fm2.py`: a Python script that converts a Brainfuck program into an FCEUX movie file that enters the Brainfuck program into the NES program
## Features
* maximum program size: 239 (8×30−1) instructions
* maximum output size: 240 (8×30) bytes
* Brainfuck RAM size: 1,024 bytes
* output speed: 1 character/frame
## Technical info
* mapper: NROM
* PRG ROM: 16 KiB
* CHR ROM: 8 KiB
* name table mirroring: vertical
* compatibility: NTSC & PAL
## How to use
There are two modes.
### Edit mode
* the program starts in this mode
* the cursor (blinking square) is always on the program input area
* note: the Brainfuck program won't run if brackets don't match
### Run mode
* there are three submodes:
* if the cursor is on the output area: the Brainfuck program is running
* if the cursor is on the virtual keyboard: the user is expected to enter a character
* if the cursor is next to the `B=exit` text: the Brainfuck program has finished or the maximum output size has been reached
* press B at any time to return to edit mode
## Character set
* output behavior:
* byte `0x0a` moves the cursor to the start of the next line
* other bytes advance the cursor by one
* output appearance:
* bytes `0x20` to `0x7e`: as in ASCII
* some bytes from `0x7f` on contain special characters
* other bytes are blank
* input (virtual keyboard):
* newline symbol (↵ at bottom right) inserts byte `0x0a`
* other symbols insert bytes `0x20` to `0x7e`
## References
* [Wikipedia – Brainfuck](https://en.wikipedia.org/wiki/Brainfuck)
* [Esolang – Brainfuck](https://esolangs.org/wiki/Brainfuck)
* [NESDev Wiki](https://www.nesdev.org/wiki/)