https://www.emulationonline.com/ Recent content in Emulators and Retro System Deep-dives on Emulation Online Hugo -- gohugo.io en-us Mon, 03 Jun 2024 16:27:40 -0700 https://www.emulationonline.com/posts/comparing-scripting-language-speed/ Wed, 04 Mar 2026 08:21:51 -0600 https://www.emulationonline.com/posts/comparing-scripting-language-speed/ Comparing Scripting Language Speed By building a programming language interpretter What is an interpretter A simple machine: The Turing Machine Why build an interpretter Measuring Performance Programming Language Runtime Comparisons / Benchmarks Why so slow? (Interpretter Overhead) Why so fast? (JIT optimizations) Environment information Host / Ubuntu Python3 Python2 Lua LuaJIT Javascript / NodeJS / V8 Ruby Ruby with YJIT PHP Stay tuned Ever wonder how fast your favorite programming language is? https://www.emulationonline.com/posts/programming-language-complexity/ Tue, 24 Feb 2026 06:56:08 -0600 https://www.emulationonline.com/posts/programming-language-complexity/ Programming Language Complexity How complex is your programming language? In this article we’ll look at a few ways of quantifying complexity, and use it to look at a variety of programming languages in frequent use today. Why? When building emulators, we ultimately have to capture the complexity of another (hardare) system in software. Having some good way of looking at and comparing complexity is useful. Similarly, the tools (languages) we use for building these emulators impacts the complexity of the resulting work. https://www.emulationonline.com/posts/best-android-ds-nds-emulators/ Fri, 20 Feb 2026 07:51:32 -0600 https://www.emulationonline.com/posts/best-android-ds-nds-emulators/ The Best Nintendo DS Emulators for Android: Accuracy vs. Performance For over a decade, Nintendo DS emulation on Android was a “solved” problem. You either used DraStic for speed or struggled with unoptimized PC ports. But 2026 has brought a seismic shift. Between the massive “blackmagic3” updates to the melonDS core and the rise of high-performance wrappers like PicoDS, choosing an emulator is no longer just about which one runs; it’s about how much fidelity your hardware can handle. https://www.emulationonline.com/posts/retro-console-cpu-timeline/ Thu, 19 Feb 2026 14:17:35 -0600 https://www.emulationonline.com/posts/retro-console-cpu-timeline/ Retro Console CPU Timeline This page lets you explore the speed of retro gaming consoles. It is truly impressive how much old consoles managed to accomplish with relatively modest capabilities. This graphs the frequency of each system’s CPU. This is roughly equivalent to how frequently each CPU was able to execute one task. Though this is a slight simplification, especially on later systems where multiple steps or “cpu cycles” are required to complete one instruction. https://www.emulationonline.com/posts/retro-console-timeline/ Wed, 28 Jan 2026 16:17:35 -0600 https://www.emulationonline.com/posts/retro-console-timeline/ Retro Console Timeline This page lets you explore the history of retro gaming consoles, as well as how popular each system was. This lets you see how popular gaming has gotten over time, as well as learn more about your favorite consoles. Note: Many systems were not released worldwide, and instead typically launched first in the country of the creator and then later released abroad. The dates we use for the initial release are of the initial “home country” release. https://www.emulationonline.com/posts/web-based-emulators-safe-online-gaming/ Tue, 20 Jan 2026 13:38:03 -0600 https://www.emulationonline.com/posts/web-based-emulators-safe-online-gaming/ Play Retro Games Safely in Your Browser: The Power of Web-Based Emulators The thrill of rediscovering classic games from your childhood is timeless. Who doesn’t want to fire up a game of with your favorite Italian Plumber, or blue hedgehog? For years, the only way to do this on your PC was through emulators. But this often came with a catch. Are ROM games safe? Is there an easier way to get your retro gaming fix? https://www.emulationonline.com/posts/newsletter-signup/ Wed, 14 Jan 2026 09:32:54 -0600 https://www.emulationonline.com/posts/newsletter-signup/ Thanks for joining the newsletter! New posts about emulators and retro gaming systems are coming your way. In the mean time, perhaps you’d also like to follow us on one of our socials. We also have a small but growing discord channel if you’d like to hang out. https://www.emulationonline.com/posts/best-psx-ps1-playstation-emulator-android/ Mon, 12 Jan 2026 18:19:56 -0600 https://www.emulationonline.com/posts/best-psx-ps1-playstation-emulator-android/ The Top 3 PS1 Emulators for Android (2026 Comparison): Which One Should You Buy? Reliving the golden age of 32-bit gaming has never been easier. With modern Android devices, you can carry your entire PlayStation 1 library in your pocket. However, the Google Play Store is crowded with options, and choosing the right one can be the difference between a nostalgic paradise and a major headache. Today, we are comparing the top three contenders: the newcomer PicoStation, the graphics powerhouse DuckStation, and the legacy veteran ePSXe. https://www.emulationonline.com/posts/cd-formats-emulation-iso-cue-bin-chd/ Mon, 05 Jan 2026 10:33:03 -0600 https://www.emulationonline.com/posts/cd-formats-emulation-iso-cue-bin-chd/ Popular File formats for CD Emulation In this article we’ll talk about the most common formats used for representing CD data for emulators. If you’re confused about cue vs bin vs iso vs chd, this is the article for you. CUE and BIN files These files originate from thinking about CDs as holding a collection of audio tracks. A .cue is sort of like a table of contents, and .bin files are the raw data of the tracks. https://www.emulationonline.com/posts/best-pc-engine-emulator-android/ Sun, 04 Jan 2026 09:47:11 -0600 https://www.emulationonline.com/posts/best-pc-engine-emulator-android/ Best PC Engine & TurboGrafx-16 Emulators for Android in 2026: PicoEngine vs. The Rest In Japan, the PC Engine was a titan that briefly outsold the Famicom (NES). In the US, it was known as the TurboGrafx-16, a cult classic that bridged the gap between the 8-bit and 16-bit eras. Today, both libraries are considered legendary, home to some of the best shooters, platformers, and RPGs ever made. However, emulating this system on Android has historically been tricky. https://www.emulationonline.com/posts/best-master-system-emulator-android/ Sat, 03 Jan 2026 08:47:11 -0600 https://www.emulationonline.com/posts/best-master-system-emulator-android/ Best Sega Master System Emulators for Android in 2026: PicoMaster vs. The Rest Before that blue hedgehog exploded onto the scene with the Genesis, the Sega Master System (SMS) laid the groundwork with 8-bit classics like Phantasy Star, Alex Kidd, and Wonder Boy. Today, your Android phone is powerful enough to run these games perfectly. But which emulator offers the best experience? Do you need a complex, all-in-one app, or something simple that just works? https://www.emulationonline.com/posts/best-gameboy-emulator-android/ Fri, 02 Jan 2026 11:47:11 -0600 https://www.emulationonline.com/posts/best-gameboy-emulator-android/ Best Gameboy Emulators for Android in 2026: PicoBoy vs. The Veterans Reliving the golden era of handheld gaming has never been easier. Whether you want to replay your favorite monster pet simulator, or explore newly created indie games for the system, your Android phone is the perfect device to emulate the classic Gameboy and Gameboy Color hardware. But with dozens of emulators on the Play Store, which one should you choose? https://www.emulationonline.com/systems/pc_engine/emulator/ Thu, 18 Dec 2025 12:58:25 -0600 https://www.emulationonline.com/systems/pc_engine/emulator/ PicoEngine (Web): Online PC Engine Emulator Upgrade for save support. Android, Desktop+Web+iOS Built in games: - Special Ninja Squad (demo) by Vectrex28 Reflectron by Aetherbyte Studios Find more on Itch.io Load your own: Video Scale 1x 2x 3x On Screen Controls (keyboard alternative in parentheses) (arrow keys) ▲ ◀ ▶ ▼ 1 (Z) 2 (X) Select (Shift) Run (Enter) Upgrade to add save support. Android Other platforms (desktop + web + iOS) Upgrade More details below Keyboard Controls: GBA Keyboard ArrowsArrow Keys 1Z 2X SelectShift RunEnter About PicoEngine (Web) PicoEngine makes it possible to play legal backups of your favorite games. https://www.emulationonline.com/posts/cross-platform-ios-web-gaming-emulators/ Wed, 03 Dec 2025 14:08:35 -0600 https://www.emulationonline.com/posts/cross-platform-ios-web-gaming-emulators/ The future of Retro Gaming is on the Web. One app for Desktop, Android, iOS and more. If you’ve been following us for a while, you know we build great emulators. Simple, accurate, and powerful for Android and Web. Our Android apps are currently have some features we’d like to bring to Web and iOS: full-screen gaming support, so it feels like a native app on-screen touch controls, imitating the feeling of either a horizontal or vertical gaming handheld auto saves, so you can play on your own schedule without worrying about losing your progress. https://www.emulationonline.com/posts/best-android-gba-emulators/ Mon, 01 Dec 2025 09:06:52 -0600 https://www.emulationonline.com/posts/best-android-gba-emulators/ The Ultimate GBA Emulator Showdown: Accuracy, Controls, and Convenience (Featuring PicoAdvance) I. Introduction: Why the Right GBA Emulator Still Matters The Golden Age of portable gaming may be behind us, but the demand for classic Game Boy Advance titles remains stronger than ever. Yet, nostalgia alone isn’t enough; today’s retro gamers demand precision, reliability, and modern convenience when revisiting classics. The challenge lies in choosing an emulator that respects the original hardware while adapting to a touch-screen world. https://www.emulationonline.com/posts/embeddable-gba-for-web/ Sat, 29 Nov 2025 19:53:16 -0600 https://www.emulationonline.com/posts/embeddable-gba-for-web/ PicoAdvance Player Announcement A while back, we created PicoAdvance, a very accurate GBA emulator you can play in the browser. This was created for gamers, to make it easier to explore homebrew applications from the comfort of their browsers. Now we’ve created an embeddable version of the emulator, so that homebrew developers can embed their games in their own webpages. This is a great way for these engineers to show off the result of their efforts. https://www.emulationonline.com/support/ Sun, 23 Nov 2025 12:57:32 -0600 https://www.emulationonline.com/support/ Help & Support Having trouble with one of our apps? We’re here to help. Email Feel free to send us an email at support@emulationonline.com. We respond to all emails, though it may take a few days depending on our current email backlog. Socials You can also reach out to a variety of our other social network accounts, though we check email most often. Other apps Maybe everything is going great and you just want to explore our other apps? https://www.emulationonline.com/systems/gba/player/ Sun, 23 Nov 2025 02:47:59 -0700 https://www.emulationonline.com/systems/gba/player/ PicoAdvance Web by EmulationOnline 1x 2x 3x Reload https://www.emulationonline.com/emulators/ Mon, 17 Nov 2025 11:09:52 -0600 https://www.emulationonline.com/emulators/ Our Emulators On this page you can browse our emulators. Many of them you can play in the browse. We also release apps for Android, and are working on making these available for iOS as well. If you would like us to develop an emulator for your favorite system, feel free to send us an email. Emulator System Web Version Android Version Multiplatform (iOS,Android,Web,Desktop) PicoNES NES ™ PicoNES Web PicoNES Android Coming Soon! https://www.emulationonline.com/systems/master_system/emulator/ Sun, 16 Nov 2025 08:37:53 -0600 https://www.emulationonline.com/systems/master_system/emulator/ PicoMaster (Web): Online Master System Emulator Upgrade for save support. Android, Desktop+Web+iOS Built in games: - Forest Escape (demo) by Iratahack Yokai Ninja (demo) by ichigo/2minds Frontier Force (demo) by BadComputer Find more on Itch.io Load your own: Video Scale 1x 2x 3x OnScreen Controls (keyboard alternative in parentheses) (arrow keys) ▲ ◀ ▶ ▼ 1 (Z) 2 (X) Upgrade to add save support. Android: Other platforms (desktop + web + iOS) Upgrade More details below Controls: SMS Keyboard ArrowsArrow Keys 1/StartZ 2X About PicoMaster (Web) PicoMaster makes it possible to play legal backups of your favorite games. https://www.emulationonline.com/posts/best-android-gbc-emulators/ Tue, 11 Nov 2025 01:29:15 -0600 https://www.emulationonline.com/posts/best-android-gbc-emulators/ Top Gameboy Emulators for Android: My OldBoy! vs. Pizza Boy GBC vs. RetroArch (and Why PicoBoy Wins) For years, Android users searching for the perfect Game Boy Color (GBC) emulator faced a frustrating trade-off: Do you choose RetroArch for its industry-leading accuracy (via the Gambatte core) and complex setup, or do you pick simpler apps like My OldBoy!, which are starting to feel dated? There is a new solution that delivers the best of both worlds, plus features the competition can’t touch: PicoBoy. https://www.emulationonline.com/systems/gba/emulator/ Thu, 06 Nov 2025 12:58:25 -0600 https://www.emulationonline.com/systems/gba/emulator/ PicoAdvance (Web): Online GBA Emulator Upgrade for save support. Android, Desktop+Web+iOS Click the game window for fullscreen + On-screen Controls(mobile) Built in games: - Butano Fighter by GValiente Anguna by gauuu Scrolls of Fire by akouzoukos Find more on Itch.io Load your own: Video Scale 1x 2x 3x Upgrade to add save support. Android: Other platforms (desktop + web + iOS) Upgrade More details below Keyboard Controls: GBA Keyboard ArrowsArrow Keys BZ AX SelectShift StartEnter Left ShoulderA Right ShoulderS About PicoAdvance (Web) PicoAdvance makes it possible to play legal backups of your favorite games. https://www.emulationonline.com/systems/gameboy/picoboy/ Mon, 03 Nov 2025 11:55:18 -0600 https://www.emulationonline.com/systems/gameboy/picoboy/ Download on Google Play PicoBoy for Android GBC Emulator The Iconic Game Boy ™ Experience. Rebuilt for Android. Your pocket-sized portal to gaming's golden age. Relive your favorites, flawlessly. Download on Google Play Requires Android 8.0 or later. Play Your Way. Flawlessly. 👾 Pixel-Perfect Accuracy Experience the classics exactly as you remember them. Zero lag, perfect graphics, and iconic sound. 💾 Ubersaves Never lose your progress again. Automatically save and loads your progress, so you can play on your own schedule. https://www.emulationonline.com/posts/how-to-run-basic-qbasic-on-dosbox/ Wed, 08 Oct 2025 09:03:45 -0500 https://www.emulationonline.com/posts/how-to-run-basic-qbasic-on-dosbox/ How to run Basic (QBASIC) on Dosbox on Modern Computers QBasic was a popular programming environment, originally bundled with MS-DOS based computers. It was the first programming environment for many computing users. While old, there are many things about this programming environment that make it ideal even today. While most computers aren’t running DOS anymore, we can still run QBasic. In this tutorial we will get QBASIC running on whatever computer you use today. https://www.emulationonline.com/systems/basic/online_interpreter/ Mon, 06 Oct 2025 15:46:02 -0500 https://www.emulationonline.com/systems/basic/online_interpreter/ Online Basic Interpreter Write and run BASIC programs in your browser! Our web-based BASIC interpreter has support for most QBASIC features. This makes it easy to learn BASIC online, and run your favorite programs. New to BASIC? See our Learn Basic page. Current Features input / print for loops integer (default) or string (name ending with $) variables conditionals (if COND then STATEMENT) Coming soon: Arrays ELSE, optional clause for IF Program: print " https://www.emulationonline.com/systems/basic/learn-basic/ Mon, 29 Sep 2025 00:57:56 -0500 https://www.emulationonline.com/systems/basic/learn-basic/ Learn BASIC programming and BASIC Quick Reference (and compare classic BASIC, QBASIC, Commodore BASIC, and Applesoft BASIC Want to learn BASIC programming? Or perhaps you’re writing a program and just need a quick reference for language keywords, for either classic BASIC or one of the successor BASIC languages which added structured programming language features. In either case, this page should have what you need. (and compare classic BASIC, QBASIC, Commodore BASIC, and Applesoft BASIC Classic BASIC vs QBASIC compatible structured programming. https://www.emulationonline.com/posts/embeddable-nes-for-web/ Sat, 30 Aug 2025 16:27:40 -0700 https://www.emulationonline.com/posts/embeddable-nes-for-web/ PicoNES Player Announcement We have just created PicoNES Player, an embeddable NES emulator for the web. If you write NES homebrew and would like to share it with visitors on your website, you can add PicoNES Player and it will automatically load and play your games! The homebrew community is awesome, and we wanted to make it easier to share these great projects. How to use PicoNES Player If you run a webpage, and want to point PicoNES Player to your games, you just need to add this snippet to your webpage, somewhere in the body. https://www.emulationonline.com/systems/nes/player/ Tue, 26 Aug 2025 12:47:59 -0700 https://www.emulationonline.com/systems/nes/player/ PicoNES Web by EmulationOnline 1x 2x 3x Reload https://www.emulationonline.com/posts/best-nes-emulator-android/ Sun, 24 Aug 2025 00:00:00 +0000 https://www.emulationonline.com/posts/best-nes-emulator-android/ The Best NES Emulator for Android: A Head-to-Head Comparison (2025) So, you want to play classic NES games on your Android phone. A quick search on the Play Store reveals dozens of options, all claiming to be the best. How do you choose? The right app can be the difference between a frustrating experience and pure nostalgic joy. In this guide, we'll compare the most popular NES emulators for Android to help you find the perfect one for your needs. https://www.emulationonline.com/posts/how-to-play-nes-games-on-android/ Sat, 23 Aug 2025 16:27:40 -0700 https://www.emulationonline.com/posts/how-to-play-nes-games-on-android/ The Ultimate Guide: How to Play NES Games on Android in 2025 Remember the magic of the Nintendo Entertainment System? The iconic grey box, the satisfying click of a cartridge, and the unforgettable soundtracks. For many of us, those games were more than just a pastime—they were a core part of our childhood. What if you could relive that experience right on the Android phone in your pocket? You can, and this guide will show you how. https://www.emulationonline.com/systems/nes/picones/ Fri, 22 Aug 2025 17:12:07 -0700 https://www.emulationonline.com/systems/nes/picones/ PicoNES Your NES favorites, playable on Android. Jump right back into the action with Auto-Save and a built-in game. No setup required. Get it on Google Play Why PicoNES? 🎮 Play Instantly PicoNES comes with a free, built-in game made by our team, so you can start playing right away. Experience that new console feeling just like the old days. 💾 Never Lose Your Progress Our auto-save feature means your game is always safe. https://www.emulationonline.com/systems/chip8/control-flow-and-graphics/ Mon, 10 Feb 2025 18:13:11 -0800 https://www.emulationonline.com/systems/chip8/control-flow-and-graphics/ Chip-8 Control Flow and Graphics Welcome. Last time we looked at the general process for implementing instructions on our Chip-8 emulator. With the ability to extract operands from instructions, we know what the instruction is meant to do. And as a bonus, the bit manipulation tricks we used were also instuctions of the Chip-8. So now we know how to implement a good chunk of basic data manipulation instructions. Now lets try to do something visual, and add graphical support to our emulator. https://www.emulationonline.com/systems/chip8/implementing_chip8_instructions/ Wed, 15 Jan 2025 19:32:57 -0800 https://www.emulationonline.com/systems/chip8/implementing_chip8_instructions/ Implementing Chip-8 Instructions Welcome back to this series on building a Chip-8 emulator. Last time we looked at an outline for how the Chip-8 emulator works, and gave it the ability to run programs. But so far, it doesn’t know how to do anything inside that program. This time we’ll add some basic operations aka instructions to our emulator. Recognizing Chip-8 Instructions Masking and selecting bits. Shifting bits Registers and implementing the 6XNN instruction Conclusion Recognizing Chip-8 Instructions Last time we saw that each operation is represented by two bytes, and we can combine those to get a 16 bit value that tells us which instruction to run. https://www.emulationonline.com/systems/chip8/running_programs/ Mon, 06 Jan 2025 08:27:04 -0800 https://www.emulationonline.com/systems/chip8/running_programs/ Running Chip-8 Programs Welcome back to this Chip-8 Emulation series. Last time we looked at some basic details of the Chip-8, and how programs are represented. Now lets look at what it takes to build a very basic emulator. We’ll start by implementing a few basic instructions. Storing a program We saw that a Chip-8 program is essentially a list of numbers. These numbers are also called “opcodes”, which can translate between the operation we want to perform, and a number that can be represented easily within a computer. https://www.emulationonline.com/systems/chip8/intro/ Sun, 29 Dec 2024 16:26:15 -0800 https://www.emulationonline.com/systems/chip8/intro/ Chip-8 Introduction In this series of posts we will be building an emulator for the Chip-8 system. If you are already interested in the Chip-8, or want to learn how emulators work, this is a great place to start. If you are more familiar with emulators and instead want to learn about a more involed system, take a look at our NES series instead. The Chip-8 is a very simple system, but has all the same parts as more complex systems. https://www.emulationonline.com/systems/chiplab/65816-hardware-support/ Tue, 26 Nov 2024 13:14:51 -0800 https://www.emulationonline.com/systems/chiplab/65816-hardware-support/ Supporting the 65816 CPU in the Chiplab A hardware perspective. Welcome. In this post we’ll look at supporting the 65816 CPU in our hardware research platform, the Chiplab. If you’re new to this series, you might find the additional context from earlier articles helpful. Find out more at the Chiplab home page. While we have a 6502 supported in the lab, we would like to generalize this to support many other types of integrated circuit. https://www.emulationonline.com/about/ Tue, 19 Nov 2024 12:41:20 -0800 https://www.emulationonline.com/about/ About EmulationOnline is a project by Elemenity LLC. We’re a a small team dedicated to both researching and developing emulators for classic computer or gaming systems. Studying classic systems provides a way to discover clever optimization and design techniques that were more necessary for slower hardware of the past. Building emulators for these systems allows us to test our understanding of these systems. It also allows us to preserve the experience of interacting with these systems, long after the original hardware stops functioning. https://www.emulationonline.com/privacy-policy/ Wed, 06 Nov 2024 10:31:26 -0800 https://www.emulationonline.com/privacy-policy/ Privacy Policy Privacy is very important to us. We design our apps and services to collect the minimum information required. On this page we outline the specifics of what information may be collected. Crash Reports We want to be able to improve our apps and services over time. While we try to test everything, we’re a small team. If you notice a crash, this will likely be logged and reported automatically. https://www.emulationonline.com/systems/chiplab/experimenting-with-highspeed-chips/ Wed, 09 Oct 2024 11:53:57 -0700 https://www.emulationonline.com/systems/chiplab/experimenting-with-highspeed-chips/ Experimenting with High-Speed Chips Trying to add an NMOS 6502 (from the NES) to the Chiplab. Last time I got a 6502 CPU fully supported in the Chiplab. You can use an in-browser assembler to write your code, then upload them to run your programs against a real 6502. Now that the chiplab is fully working for a simple chip, its time to start adding some more interesting systems. Next up is the 2A03 CPU from the NES. https://www.emulationonline.com/shop/chiplab_6502/ Mon, 30 Sep 2024 11:39:58 -0700 https://www.emulationonline.com/shop/chiplab_6502/ 6502 Chiplab Dev Board Write and run programs for a real 6502! This USB device lets you upload programs to run against the classic 6502 CPU, made famous by the NES, Apple ][, and Commodore PET. Write programs from the comfort of a modern machine, then upload your programs via USB. Version: With 6502 Chip ($70) Without 6502 ($55) Buy Description This system lets you save time, and gives you the most accurate environment for running 6502 based programs. https://www.emulationonline.com/systems/chiplab/6502-lab-available/ Wed, 25 Sep 2024 11:35:44 -0700 https://www.emulationonline.com/systems/chiplab/6502-lab-available/ 6502 Available in the Chiplab Run your programs against a real 6502. 6502 As A Service. The 6502 is now available in the Chiplab! This allows you to upload your programs to be queued for running against a real 6502 chip. For each cycle of execution, you can observe the values of all the busses of the physical chip. This can be used in place of an emulator for a highly accurate way to test your 6502 programs. https://www.emulationonline.com/shop/cogni_mcu_devboard/ Mon, 23 Sep 2024 12:15:33 -0700 https://www.emulationonline.com/shop/cogni_mcu_devboard/ Cogni (3.3V) Dev Board Add brains to your electronics projects Cogni makes it easy to add progammability to your existing electronics projects, or prototype your larger ideas. It features a USB Micro B connector for programming and serial communication. Version: 3.3V version ($15) 5V version ($10) Buy Now ($15) Description This development board makes it easy to build an initial prototype of your project on a breadboard, and later integrate into complete designs. https://www.emulationonline.com/systems/nes/apu-audio/ Wed, 18 Sep 2024 11:35:36 -0700 https://www.emulationonline.com/systems/nes/apu-audio/ NES Audio (APU) In this article we will be looking at the sound features of the NES. We’ll learn how to emulate sound at a high level, and also write programs that generate sound on the NES. Sound on the NES is handled by some custom hardware, often called the “Audio Processing Unit” or APU, which is embedded in the CPU Chip (the Ricoh 2A03). Introduction Hardware Features Sound wave types Pulse 1 & 2 Triangle Noise DMC Controlling the Sound Hardware Status (0x4015) Pulse 1 Registers (0x4000 - 0x4003) Frame counter (0x4017) Writing a test program Testing sound support Other Quirks Extra resources Introduction When we looked at the NES Graphics hardware, we saw that the NES uses a number of tricks in order to minimize storager requirements, while enabling a great deal of flexibility for developers. https://www.emulationonline.com/systems/chiplab/6502/assembler/ Thu, 12 Sep 2024 19:28:44 -0700 https://www.emulationonline.com/systems/chiplab/6502/assembler/ Online 6502 Assembler This is a 6502 assembler I wrote, originally to support the 6502 chiplab. You can inspect the assembler output in the hex editor, and you can also download your assembled programs. You can run your programs on an emulator of choice. I have also made a real 6502 available online, and you can submit your programs to run against a real chip. You can learn more about the 6502, and get links to other resources at my 6502 page. https://www.emulationonline.com/systems/background/digital-sound/ Tue, 10 Sep 2024 10:58:36 -0700 https://www.emulationonline.com/systems/background/digital-sound/ Digital Audio Primer Aka Sound for Programmers Aka Sound for Programmers Sound 101 Amplitude Frequency Audio Digitization Sampling Quantization Common Wave Types Sine Square / Pulse Triangle Sawtooth Conclusion Many systems contain hardware to generate sound. To understand the hardware behind audio synthesis, it helps to know how sound can be represented digitally. Sound 101 The sound we hear is just changes in air pressure on our ears. The key information communicated by the sound is this variation in pressure over time. https://www.emulationonline.com/systems/chiplab/desoldering-ics/ Mon, 02 Sep 2024 10:58:00 -0700 https://www.emulationonline.com/systems/chiplab/desoldering-ics/ Desoldering ICs With all the electronics completed for the 6502 chiplab, it is time to look at adding a few other chips. System 1: Original Gameboy (DMG) Heat Gun Desoldering for SMT components Hot Plate Desoldering System 2: The NES Tools Used Conclusion Many of the chips I would like to research with the chiplab are not commercially available, and can only be acquired by extracting them from existing systems. https://www.emulationonline.com/tools/ Sun, 01 Sep 2024 12:33:00 -0700 https://www.emulationonline.com/tools/ Tool Recommendations These are various tools I use regularly and can recommend. Whether you are just curious about what I use, or are trying to complete similar projects, here are some tools I can vouch for. If you purchase from one of the links below, I may get a small proceed, at no extra cost to you. However I only share the tools I enjoy using. Hardware These are the tools I use for prototyping, rework, and sometimes extracting rare chips for use in my own projects. https://www.emulationonline.com/systems/chiplab/flashing-arduino-bootloader/ Sat, 31 Aug 2024 09:59:40 -0700 https://www.emulationonline.com/systems/chiplab/flashing-arduino-bootloader/ Flashing the Arduino Bootloader onto a Custom PCB In this article I’ll talk about how I managed to program (aka flash) an Arduino bootloader onto my custom atmega based circuit board. This enables me to use the Arduino IDE with my custom board, making it easier for myself and others to contribute to firmware projects. Some details are a bit finicky and poorly documented online, particularly involving the fuse bits. I’ll share how I flashed the bootloader onto my custom board, as well as an Arduino nano clone that shipped with an out of date bootloader. https://www.emulationonline.com/systems/nes/controller/ Thu, 29 Aug 2024 11:44:30 -0700 https://www.emulationonline.com/systems/nes/controller/ How the NES controller works. Now that we’ve wrapped up a high level model for the graphics system, its time to add interactivity to our emulator. We’ll take a look at how the NES controller port works, and how the standard controller uses the port. After understanding how the port works, we’ll know how to add controller support to our emulator. Also available on Youtube The NES controller port. The standard NES controller Controller MMIO Registers 0x4016 (write) : Controller Strobe 0x4016 and 0x4017 (read) : Controller state Standard controller ordering Controller Test ROM The NES controller port. https://www.emulationonline.com/systems/nes/nes-system-timing/ Wed, 28 Aug 2024 11:05:37 -0700 https://www.emulationonline.com/systems/nes/nes-system-timing/ NES System Timing (CPU + PPU + APU) We’ve now covered the high level details of the graphical system on the NES. Now we’ll see how the graphics chip, the PPU, is synchronized with the CPU. This is key to avoid graphical artifacts, and also gives us a better idea of how the system works. The system clock NTSC PPU Timing NTSC Overview PPU Timing interrupts Emulating the Frame Timing High level video timing. https://www.emulationonline.com/systems/nes/backgrounds-and-nametables/ Sun, 18 Aug 2024 13:13:30 -0700 https://www.emulationonline.com/systems/nes/backgrounds-and-nametables/ Background Graphics Last time we took a look at how the NES handles highly flexible graphics using sprites. Now we’ll see how the NES generates background images. Also on Youtube. Background vs foreground capabilities NES Nametables Tile data Attribute data Decoding Example Background windows Nametable mirroring Conclusion Background vs foreground capabilities Before diving in and learning how backgrounds work, we can compare the functionality of background graphics against the sprites we looked at last time. https://www.emulationonline.com/systems/chiplab/emulating-program-rom/ Wed, 14 Aug 2024 18:37:33 -0700 https://www.emulationonline.com/systems/chiplab/emulating-program-rom/ Emulating Program ROM Now that we can read the full address bus from the 6502, we have enough visibility to try to run a program on the 6502. Experiment outline The test program (for the 6502) The host program, driving the atmega (from a linux machine) The atmega program, driving the 6502 Running the experiment. Chiplab update: We’ll update our control program on the atmega, and write a program that talks to the atmega via serial to feed in the appropriate data from an emulated ROM chip. https://www.emulationonline.com/systems/nes/sprite-rendering/ Tue, 13 Aug 2024 11:59:37 -0700 https://www.emulationonline.com/systems/nes/sprite-rendering/ Sprite Rendering on the NES Now that we know how to specify colors in the NES palette, lets use this to actually draw an image. First, we’ll take a look at objects or sprites, which are used to draw characters and other accent details on top of the background. Also available on Youtube. High level Graphics Emulation Sprite Support on the NES Drawing a simple sprite OAM MMIO Addresses OAM Layout Test ROM OAMDMA High level Graphics Emulation Note that for this article, we will cover a high level perspective of how sprite rendering works. https://www.emulationonline.com/systems/chiplab/extending-io/ Sat, 10 Aug 2024 14:53:17 -0700 https://www.emulationonline.com/systems/chiplab/extending-io/ Extending IO Last time we wired up a rough prototype of the Chiplab for a 6502. Due to limited pins on our atmega based Arduino board, we were unable to interact with all the pins on the 6502. This meant we couldnt see the entire address bus, so only had a narrow view of what the 6502 was doing. This time we’ll work around this limitation with some extra electronics. https://www.emulationonline.com/socials/ Mon, 05 Aug 2024 10:31:09 -0700 https://www.emulationonline.com/socials/ Social Media Links Follow along for updates however it is convenient for you. I post about new updates on the following social networks. Email Newsletter TikTok Youtube Mastodon Discord Twitter RSS Feed If you like the writing or apps we create, there are a few ways to help us out. First is sharing the site with others that you think would enjoy it. Another would be to take a look at our emulators page and try out some of our apps. https://www.emulationonline.com/all-posts/ Fri, 02 Aug 2024 10:20:08 -0700 https://www.emulationonline.com/all-posts/ All Posts On this page you can find all posts on this site. Newest posts are on top. You might find this handy to check if you’ve missed posts since you last visited the site. I also have an RSS feed if you’d like to follow but not join the email list. I personally like the email feed because it lets me know how many people are interested. But I understand if you want the extra privacy of an RSS feed. https://www.emulationonline.com/systems/nes/graphics-palette/ Thu, 01 Aug 2024 10:20:08 -0700 https://www.emulationonline.com/systems/nes/graphics-palette/ NES Graphics Palette The NES palette. Controlling the palette MMIO PPU Palette MMIO PPU VRAM Memory Map: Color interpretation Palette Test ROM Summary / Palette Usage Graphic Setting Palette from CPU: Drawing from a tile with a Palette Next up: Foreground rendering Also available on Youtube. Last time we saw how the NES stores image data. Since image data only has 2 bits per pixel, the image doesn’t directly encode the color used. https://www.emulationonline.com/systems/chiplab/6502-wiring/ Tue, 30 Jul 2024 12:34:59 -0700 https://www.emulationonline.com/systems/chiplab/6502-wiring/ Chiplab - 6502 Wiring I have a very basic prototype working on a breadboard. I’m going to share what I’ve done so far, and talk about what comes next. At this point I have the chip performing a reset, and beginning execution at an address I specify. Lets see how I got there. Also available on Youtube. The Modern 6502 6502 Pinout Powering the Chip Interfacing with an Atmega (Arduino) Basic bus operation Minimal connections Address and Data minimal connections Stepping the clock Reset + Step experiment Limitations The Modern 6502 The 6502 CPU I have selected is DIP package produced by Western Design Center. https://www.emulationonline.com/systems/chiplab/introduction/ Mon, 22 Jul 2024 12:07:22 -0700 https://www.emulationonline.com/systems/chiplab/introduction/ Chiplab Introduction Also available on Youtube Emulator development is difficult, and there are 3 key things that make it challenging. From easiest to hardest: Implementation Testing Specification Lets talk a bit more about these. Implementation of an emulator can be tricky, particularly to ensure that the emulated system can run at “full speed”. And there tend to be many little details that can be tricky to implement. However, if you have a good specification, and a good way to test and detect issues, implementation tends the be the easier of these three. https://www.emulationonline.com/systems/nes/chr-graphics/ Tue, 16 Jul 2024 11:12:46 -0700 https://www.emulationonline.com/systems/nes/chr-graphics/ NES CHR Graphics Now that we have some cartridge data loaded, lets see how the CHR graphic data is used. Also available on Youtube. Graphics Primer CHR data CHR Tile Decoding Example CHR Table visualization CHR sizes Next up, colors and the palette! For these posts on graphics, we’ll be building up our knowledge “bottom up”, starting with primitive pieces and then seeing how they tie into the big picture. https://www.emulationonline.com/systems/nes/ines-loading/ Mon, 15 Jul 2024 11:13:09 -0700 https://www.emulationonline.com/systems/nes/ines-loading/ INES Cartridge Loading Now that we know what a simple cartridge looks like, lets see how cartridge data is represented. Also available on Youtube. INES File Format INES for NROM INES Header 6502 Reset Vector. INES NROM Reset Test Next up, CHR graphics! INES File Format The format most often used for cartridge dumps is called INES, named after the emulator that developed the format. INES files are usually named with a “. https://www.emulationonline.com/systems/nes/cartridge-basics/ Thu, 27 Jun 2024 10:48:35 -0700 https://www.emulationonline.com/systems/nes/cartridge-basics/ Cartridge Basics Also available on Youtube. Now that we’ve seen how the CPU works, lets see how the CPU loads its instructions. The NES uses cartridges, which are essentially circuit boards that plug into a slot on the main NES circuit board. They’re encased in plastic cases, so unless you peek in side its easy to miss this fact. Let’s peek inside the cartridge for the NES game Pinball. On the bottom we see what is sometimes called “gold fingers”, and are where the cartridge would plug into the main system. https://www.emulationonline.com/systems/nes/roms/nestest_bin/ Thu, 27 Jun 2024 09:30:51 -0700 https://www.emulationonline.com/systems/nes/roms/nestest_bin/ NesTest (Binary) Info This is a conversion of the excellent nestest.nes. While the original nestest does a great job of testing CPU quirks, it can be a little hard to use for early CPU implementations. In order to run it, you need to support loading .NES formatted files. I did not write the original nestest.nes, but I have found in incredibly helpful for the development of my own 6502 emulator. https://www.emulationonline.com/systems/nes/6502-emulation-tips/ Thu, 13 Jun 2024 10:03:43 -0700 https://www.emulationonline.com/systems/nes/6502-emulation-tips/ 6502 Emulation Tips Also available on Youtube. Before we wrap up the CPU portion of the NES, I thought I’d provide some tips I’ve learned while developing my emulator. Testing Test Programs Nestest.NES 6502 Quirks Page Crossing Memory space collisions Two interpretations of Addressing Modes Next up: Cartridges Testing Though the 6502 CPU was originally released in 1975, it is still a fairly complex device. There are many opportunities for errors while developing an emulator. https://www.emulationonline.com/systems/nes/6502-status-interrupts-stack/ Fri, 07 Jun 2024 10:39:14 -0700 https://www.emulationonline.com/systems/nes/6502-status-interrupts-stack/ More 6502 Details. Negative Numbers, Status, and Interrupts Also available on Youtube. Negative Numbers (Twos Complement) 6502 Status Register Negative Overflow (Signed overflow) Break Interrupt Disable Zero Carry (Unsigned overflow) Updating the Status register Interrupts The Stack 6502 Explored! Last time we looked at CPU instructions for the 6502, and got a general idea for how these work. Before we’re ready to start implementing the full instruction set, there are a few more details we need to understand. https://www.emulationonline.com/systems/nes/coding-a-6502-emulator/ Tue, 04 Jun 2024 16:09:39 -0700 https://www.emulationonline.com/systems/nes/coding-a-6502-emulator/ 6502 Emulator Design Also available on Youtube. Now that we’ve seen the registers used in the 6502 CPU of the NES, we’re ready to start building the CPU emulator. The CPU essentially does the following for each step: Determine what instruction it is going to run Read that instruction Decode it so it knows what to do Do the requested action Repeat Lets talk about each of these steps in more detail. https://www.emulationonline.com/systems/nes/6502-assembly-language/ Tue, 04 Jun 2024 12:21:34 -0700 https://www.emulationonline.com/systems/nes/6502-assembly-language/ 6502 Assembly Language Also available on Youtube. In the previous post we looked at the key components that make up the NES, and learned a bit about how computers represent values and how they’re stored in memory. One issue mentioned was that memory is physically outside the CPU, and thus slower to access. How does a CPU, particularly the 6502-like CPU in the NES, work around that? The answer is registers! https://www.emulationonline.com/systems/nes/overview/ Mon, 03 Jun 2024 18:26:15 -0700 https://www.emulationonline.com/systems/nes/overview/ NES System Architecture and CPU Basics Watch on Youtube Building an emulator means building software simulations of they key features of the system. Before we get started, lets take a look at the hardware present in the NES: CPU: Ricoh 2A03 Graphics: The “PPU”, a custom Nintendo® chip Sound: The “APU”, another custom chip Cartridge: Varies by game All of these are critical to the function of the system. Fortunately, we can build one piece at a time, building up the complete function of our emulation.