sf2000/README.md

# SF2000
The SF2000 is a cheap hand-held emulation gaming console which was released in early 2023. Although the device itself is sold by a variety of vendors, it was the vendor "Data Frog" who caught public attention, and so the device is often simply referred to as "the Data Frog".

This document is a collection of notes and information I've made about the device.

---

## Table of Contents
- [SF2000](#sf2000)
  - [Table of Contents](#table-of-contents)
  - [FAQ (Frequently Asked Questions)](#faq-frequently-asked-questions)
    - [Is this thing any good?](#is-this-thing-any-good)
    - [Is there any custom firmware?](#is-there-any-custom-firmware)
    - [I just got my SF2000; what modding can I do with it?](#i-just-got-my-sf2000-what-modding-can-i-do-with-it)
    - [How do I install new menu themes?](#how-do-i-install-new-menu-themes)
    - [How do I change the four shortcuts/games listed on each system's main menu page?](#how-do-i-change-the-four-shortcutsgames-listed-on-each-systems-main-menu-page)
    - [SNES games run really slowly... what's wrong?](#snes-games-run-really-slowly-whats-wrong)
    - [Help! I was doing stuff in the bios folder or trying to install a new firmware, and now my SF2000 won't turn on, or is stuck at a black screen!](#help-i-was-doing-stuff-in-the-bios-folder-or-trying-to-install-a-new-firmware-and-now-my-sf2000-wont-turn-on-or-is-stuck-at-a-black-screen)
    - [When I connect the SF2000 to a TV via the A/V cable, the sound is very quiet/low - is that normal?](#when-i-connect-the-sf2000-to-a-tv-via-the-av-cable-the-sound-is-very-quietlow---is-that-normal)
    - [Game saves don't seem to be working for me? Save states are fine, but the built-in save function in games doesn't seem to work?](#game-saves-dont-seem-to-be-working-for-me-save-states-are-fine-but-the-built-in-save-function-in-games-doesnt-seem-to-work)
  - [Hardware](#hardware)
    - [CPU](#cpu)
    - [Display](#display)
    - [Buttons](#buttons)
    - [D-Pad](#d-pad)
    - [Thumb Stick](#thumb-stick)
    - [Battery](#battery)
    - [Wireless Connectivity](#wireless-connectivity)
    - [A/V Output](#av-output)
  - [Emulators](#emulators)
    - [Arcade](#arcade)
      - [.skp Files](#skp-files)
    - [NES](#nes)
    - [SNES](#snes)
    - [Genesis/Mega Drive](#genesismega-drive)
    - [Game Boy](#game-boy)
    - [Game Boy Color](#game-boy-color)
    - [Game Boy Advance](#game-boy-advance)
    - [Save States](#save-states)
    - [Default ROMs](#default-roms)
  - [Firmware/BIOS (bisrv.asd)](#firmwarebios-bisrvasd)
    - [Bootloader Bug](#bootloader-bug)
    - [Button Mappings/Key Bindings](#button-mappingskey-bindings)
    - [Boot Logo](#boot-logo)
  - [Resources](#resources)
    - [Fonts](#fonts)
    - [Images (Used)](#images-used)
    - [Images (Unused)](#images-unused)
    - [Other Files](#other-files)
      - [Foldername.ini](#foldernameini)
      - [Favourites and History](#favourites-and-history)
    - [ROM Lists](#rom-lists)
    - [Sounds](#sounds)
    - [Unknown Files](#unknown-files)
    - [Notes For Theme Creators](#notes-for-theme-creators)
  - [Tools and Links](#tools-and-links)
  - [Version History](#version-history)

---

## FAQ (Frequently Asked Questions)

### Is this thing any good?
For a cheap device, it's actually fairly capable - most Game Boy, Game Boy Color, NES and Genesis/Mega Drive games play at full speed, and many arcade, Game Boy Advance and SNES titles do as well. The device has an IPS panel (not OCA laminated), and a user-replaceable 18650 battery, which can be charged via a USB-C port on the device. It also has analog A/V out (note: not HDMI), meaning it can be connected to a CRT TV - the type of display most arcade, Genesis/Mega Drive and SNES games were originally intended to be displayed on. It has a built-in 2.4GHz antenna, and can receive input from a compatible wireless controller (usually sold separately).

Some downsides to the device: it's mono only (you only get the left-channel audio), there's no headphone jack (although there is a volume wheel), screen brightness cannot be altered (it's fairly bright), SNES and Game Boy Advance are hit-or-miss in terms of performance (some games are fine, many games run unplayably slowly), the stock firmware is closed-source so the device's performance may never get any better than as-shipped, and some folks have had issues with the buttons (quality control is hit-or-miss, and some folks have had terrible button response, such as a d-pad that can't do diagonals reliably, or ABXY buttons that sit flush with or even go under the case).

So is the "Data Frog" any good? Only you can answer that question for yourself. There are certainly more powerful devices out there, more fully featured devices, devices with better hardware, etc. - but almost all of those devices cost a lot more than the SF2000. At the end of the day, you have to look at the features offered at the given price-point, and only then can you decide if you're interested in the device or not.

### Is there any custom firmware?
As of July 20th 2023, **no**, not yet. However efforts are underway; an SDK for the CPU has been identified, and custom firmware is now in the very early stages of development. Most recently, a limited build of Retroarch has been demonstrated to run, with two separate cores capable of loading ROM content compiled as separate firmwares (TGBDual, the same Game Boy/Game Boy Color emulator included in the stock firmware; and gpSP, the same Game Boy Advance emulator included in the stock firmware as well). Video and audio drivers for Retroarch are at very early stages of development and are therefore not optimised, and much audio "crackling" is present under TGBDual; gpSP as of yet has no audio at all. Additionally, performance issues have been hinted at (TGBDual runs much faster when the audio subsystem is not engaged, and gpSP requires frame-skipping to be playable).

[A GitLab repo](https://git.maschath.de/ignatz/hcrtos) has been set up by `ignatzdraconis` for the work, and you can [follow along with discussion in the `Retro Handhelds` Discord](https://discord.com/channels/741895796315914271/1092831839955193987).

### I just got my SF2000; what modding can I do with it?
In no particular order, some of the current customisation options available are:

* You can [fix an annoying bug in the device's bootloader](#bootloader-bug)
* You can [upgrade the firmware to the latest version](https://www.youtube.com/watch?v=j8dT2fdGfck)
* You can swap out the [buttons](#buttons) and [d-pad](#d-pad) (and their membranes) for ones from original SNES controllers (not SNES Classic), which gives a more retro "mushy" feel (if your replacement buttons have 3 "pins", you may need to file or clip one of the pins off)
* You can swap the [battery](#battery) for a higher-capacity `3500 mAh` 18650, which will give you longer playtime (at the cost of longer charging time). If you do decide to replace the battery, make sure you use one with a built-in protection circuit, as the SF2000 has no under-charge protection.
* You can [replace the boot logo](https://vonmillhausen.github.io/sf2000/tools/bootLogoChanger.htm) with a custom one
* You can [replace the main menu music, or remove it entirely](#sounds)
* You can [change the default button mappings](https://vonmillhausen.github.io/sf2000/tools/buttonMappingChanger.htm) for each emulator (newer firmwares have this feature built-in, but the built-in implementation is buggy)
* You can add your own ROMs to the `roms` folder on the microSD card, which will then appear in the user ROMs menu of the device. You can also modify the built-in ROM lists using [FROGTOOL](https://github.com/tzlion/frogtool)
* You can [replace the default menu theme with a custom one](#how-do-i-install-new-menu-themes)

### How do I install new menu themes?
The SF2000 doesn't natively support themes at all; however, all of the images and sounds for the stock theme live in the `Resources` folder on the microSD card. Therefore, by simply replacing the stock theme's files, the stock theme can be replaced.

A new centralised repository for boot logos, custom themes and background music has been created by `Zerter#4954`, which you can [find here](https://zerter555.github.io/sf2000-collection/); you can also find many of them linked in the ["The Frog's Best Bits 🐸" thread](https://discord.com/channels/741895796315914271/1110397766074638397) in the [Retro Handhelds Discord server](https://discord.gg/retrohandhelds).

Just take the files from the theme, and use them to replace the existing files on the microSD card. You might want to make your own backup of the stock `Resources` folder first, in case you want to go back to the stock theme yourself at a later date. Note also that in addition to theme assets, [the `Resources` folder](#resources) also contains data files related to your [button mapping](#button-mappingskey-bindings), [favourites and history](#favourites-and-history), etc.; so when backing up or replacing files in `Resources` for themes, just be aware not to overwrite anything non-theme-related you want to keep.

Another thing to note: some themes might come with an updated boot logo. If that logo is provided as [a `bisrv.asd` file](#firmwarebios-bisrvasd) in the `bios` folder, this is actually a modified _firmware_ for the device, which happens to contain the new logo. If you decide to replace your existing `bisrv.asd` file, you might want to make sure that the theme's firmware version matches the firmware version already on your device. Generally, it's probably safer just to [update your own firmware's boot logo](https://vonmillhausen.github.io/sf2000/tools/bootLogoChanger.htm) with an image file.

### How do I change the four shortcuts/games listed on each system's main menu page?
Answer: with a fair bit of work! The _images_ for the shortcuts are baked into each system's main menu background image - check out the ["Images (Used)"](#images-used) section below, and use your browser's search feature to search for `main menu background`, and you'll see what I mean. `Zerter#4954` has created a tool for theme makers which lets you more easily edit these icons, [which you can find here](https://zerter555.github.io/sf2000-collection/mainMenuIcoEditor.html). The _text_ under each shortcut is stored in a separate image - in the `05.22` firmware, the files are `gkavc.ers` if the device's language is set to Chinese, or `gakne.ctp` for all other languages (again, check the details in the ["Images (Used)"](#images-used) section below). Finally, the actual roms that are launched for each shortcut are stored in the `xfgle.hgp` file, which is plain text - you can learn more about it in the ["ROM Lists"](#rom-lists) section below.

### SNES games run really slowly... what's wrong?
There's a bug in all stock firmware versions later than the original mid-March firmware which often causes SNES games to run really slowly on first launch (and their sound is slow and lower pitch too); this only impacts SNES. Usually this can be corrected by launching the game, then quitting back to the game selection menu via `START + SELECT`, and then immediately re-launching the game again. Note however that the stock firmwares do also struggle a bit with SNES emulation in general, so any additional slowdown after the second launch is just what you get.

### Help! I was doing stuff in the bios folder or trying to install a new firmware, and now my SF2000 won't turn on, or is stuck at a black screen!
You've probably run into the bootloader bug - you can [find the two fixes to it below](#bootloader-bug). Alternatively, [follow Data Frog's instructions](https://www.youtube.com/watch?v=j8dT2fdGfck) to wipe your microSD card and flash a clean firmware image.

### When I connect the SF2000 to a TV via the A/V cable, the sound is very quiet/low - is that normal?
It's "normal" for newer versions of the firmware, anyway! Older firmware versions had no issues with audio volume via A/V, but at least the `05.22` version does. `Zerter#4954` from Discord found a workaround:

> when I did this the AV audio work normally: I had to load the game first then plug-in the 2.5mm to rca jack. [...] but when I quit then exit then tried the game again it returns to very low audio. [...] will need to do the work around again

So you can try launching the game first, and _then_ plug in the A/V cable to get full volume on the TV.

### Game saves don't seem to be working for me? Save states are fine, but the built-in save function in games doesn't seem to work?
Unfortunately, correct - with the stock firmware, the built-in save feature of emulated games does not work correctly, and the SF2000 won't store new save data after the first time it's created for a game. If you want to save your progress in a game on the SF2000's stock firmware, use save states instead.

---

## Hardware

### CPU
Although the main CPU of the SF2000 has literally had it's markings milled off by a routing tool, the community has determined that it's a HCSEMI B210, a single-core MIPS processor running at 810 MHz. It appears to be a clone of an ALi Tech chip. [An SDK has been found](http://www.zcsd-tech.com//download/content-54.html) for it.

### Display
The SF2000 features a `240x320` IPS display panel (not OCA laminated), which has been rotated 90° clockwise to give a `320x240` display. It demonstrates screen tearing for all emulators, running from the right of the console to the left due to the panel rotation.

### Buttons
The ABXY are basically a clone of the original SNES controller buttons. Although everyone seems to be getting two purple and two lilac coloured buttons, there's a disparity to the _type_ of buttons folks are getting - some get two convex and two concave buttons, others have gotten three concave and one convex, etc..

Both the buttons and the underlying membrane from an original SNES controller can be swapped into the SF2000, which may improve the "feel" of the buttons. Note that the SF2000 uses ABXY buttons that have two plastic tabs sticking out to keep them in the shell (at 180 degrees from each other); some after-market SNES-style buttons have _three_ tabs, and won't fit the housing.

Some folks have modded the stock ABXY buttons on their SF2000s by adding a thin strip of tape or other thin material into the circular depression under each button - this causes the buttons to be raised a bit higher out of the shell, and to not sink as far into the shell when the button is pressed.

### D-Pad
Just like the ABXY buttons, the d-pad is a clone of the SNES d-pad. An original SNES d-pad and membrane can be swapped into the SF2000 as well.

### Thumb Stick
The SF2000 uses a Switch-style thumb stick that does _not_ depress for L2/R2. It is compatible with Switch thumb stick third-party covers.

### Battery
The SF2000 takes a 18650 type rechargeable battery, which is easily user replaceable (it's behind a battery door with a screw), and comes with a 1,500mAh one which runs for about 4 hours. 18650 batteries with and without "nubs" both fit fine. The console has built-in over-charge protection, but _does not have under-charge protection, so for safety do not leave the console turned on when the battery is low_. From when it displays a full-screen low battery indicator, it takes about 3.5 hours to charge the stock battery. The green charging light does _not_ turn off when fully charged.

Also note that while you can technically charge the SF2000 while it is powered on, doing so using a charger that supports fast charging or power delivery has a high chance of blowing the charging module IC and killing the device (multiple community reports). For safest charging, use a charger that only supports a maximum output of 5v.

### Wireless Connectivity
The SF2000 does not feature wifi or Bluetooth, but it _does_ have a 2.4Ghz antenna to support local wireless multiplayer using a compatible 2.4Ghz wireless controller for Player 2. The Y2 SFC wireless controller and the SF900 wireless controller have both been reported to work fine.

### A/V Output
The SF2000 features a mini-jack for analogue composite A/V output. The device is capable of output a user-selectable PAL or NTSC video signal. Only the _left_ audio channel is output - the device does _not_ down-mix to mono, which results in missing audio channels in games that expect to output stereo sound.

There's some limited evidence to suggest the A/V output is at 576i. When outputting a PAL signal, while the signal is indeed 50Hz, it seems like the emulators are still targeting 60Hz output - PAL scrolling is "jerky". Switching the device to output NTSC, scrolling becomes smooth. This holds true regardless of using a PAL or NTSC version of a ROM. Depending on your external display, video output over A/V may be somewhat heavily cropped on all screen edges - if so, this can result in UI elements at screen edges in games (health bars, remaining credits, etc.) being out-of-frame. Switching between PAL and NTSC doesn't alter the visible screen area. I've tested with a modern flat-panel Panasonic TV (cropped), a 1980s Commodore 1702 monitor (cropped), and with an el-cheapo USB 2.0 "EasyCap" video-capture USB stick (not cropped).

On my own unit, plugging in a charging cable while outputting over A/V introduces a lot of video noise in the A/V signal; so those planning to use the SF2000 as a TV console may need to do so while running on battery for the best experience.

---

## Emulators

The device advertises support for arcade, NES, SNES, Genesis/Mega Drive, Game Boy, Game Boy Color and Game Boy Advance; it also supports loading Master System ROMs. SNES and GBA performance are very hit-or miss (more miss than hit, really); the other consoles actually perform fairly well. All consoles currently stretch their output to fill the display, and do not maintain aspect ratio.

The SF2000 appears to be using Libretro with a custom front-end (i.e., not RetroArch).

### Arcade
The device is running Final Burn Alpha v0.2.97.42 (Git commit [`621e371`](https://github.com/Aftnet/fbalpha/commit/621e371)). Thanks to some truly exceptional work by `adcockm` from the Retro Handhelds Discord, we know it supports an unusual mix of ROM sets, largely based on MAME 0.106 and Final Burn Alpha v0.2.97.42. `adcockm` has gone ahead and compiled two separate [Clrmamepro](https://mamedev.emulab.it/clrmamepro/) dat files - [one for _all_ sets technically supported by the SF2000's current BIOS](/arcade/DataFrog_SF2000_FBA_v0.2.97.42.dat) (as of May 2023; though note that "supported" does not mean working or playable), and [one for all playable sets](/arcade/DataFrog_SF2000_FBA_v0.2.97.42_playable_no_dups.dat) with duplicates removed (and note, "playable" may include games with missing sound, graphical glitches, performance issues, but are otherwise technically functional). If you want to build a working set (must be non-merged) from the dat files, `adcockm` has further provided [a list of "hints"](/arcade/Building_the_DataFrog_SF2000_FBA_v0.2.97.42_set.txt) as the sets you'll need to track down - for obvious reasons neither I nor anyone else can provide links to such material, but hopefully the hints will get you something you can start searching for. Finally, there's also [a HTML document](/arcade/DataFrog_SF2000_FBA.html) with a list of all of the supported sets along with some useful metadata, such as the set's full name, playability information, screen orientation, etc.. The `inrom` column indicates if the ROM was included on the SF2000's stock microSD card; it's interesting to note that there were more ROMs located on the card than were defined in the `mswb7.tax` file (and thus available from the arcade game list); none of the unlisted games were actually playable on the SF2000, so it's possible someone from Data Frog actually tested the games to an extent, and removed ones from the available list that were broken.

`adcockm` also provided the following interesting statistics:

- Number of arcade ROMs known by the SF2000's firmware: `1431`
- Number properly rotated: `1291`
- Number with vertical orientation: `134`
- Number with screen upside-down: `6`
- Number "playable" (maybe no sound, some slowness, minor graphics issues): `949`
- Number unplayably broken but technically running: `175`
- Number fully broken (load hang/crash, etc.): `307`
- Number of playable unique games (dupes filtered out) in proper rotation: `354`
- Number of playable unique games (dupes filtered out) with rotated display: `61`
- Number of different versions of Street Fighter 2: `60+` 😵‍💫 [Von Millhausen: I think this stat is only half a joke!]
- Playable set total size: `3.10 GB` (3,336,344,502 bytes)
- Full set total size: `11.4 GB` (12,245,306,389 bytes)

#### .skp Files
Another thing worth mentioning about arcade emulation on the SF2000; in the `ARCADE` folder on the microSD card is a sub-folder called `skp`. This folder contains (by default) 167 `.skp` files, each named after one of the zipped ROM sets in the `ARCADE/bin` folder (e.g., `mslug.zip.skp`). These files are actually save state bundle files, just like the ones you can save yourself using the save state feature - the only difference is that these have the `.skp` extension instead of `.sa#`, and these are loaded automatically when the game itself is loaded. Many of these files start their respective arcade game up with a credit already inserted. One speculative possibility for why these files exist is that some arcade games will start to a dip-switch screen, or some other ROM-check screen, which may be difficult to bypass with the SF2000's limited controls - a save state that automatically loads _past_ such a screen is therefore very useful to have.

As the `.skp` files are just save states under a different name, if you want to mess around with them you can [use my Save State Tool](https://vonmillhausen.github.io/sf2000/tools/saveStateTool.htm) to do so - if you're creating a new `.skp` file, just pick any save state slot, and change the downloaded SF2000 save state bundle extension from `.sa#` to `.skp`.

You can [learn more about save states below](#save-states).

### NES
Emulator is FCEUmm (Git commit [`7cdfc7e`](https://github.com/libretro/libretro-fceumm/commit/7cdfc7e)). There are references in the firmware to different NES palettes, but there's no interface or configuration for the emulator itself to choose one. On the original firmware, the A and B buttons were swapped. See "[Button Mappings/Key Bindings](#button-mappingskey-bindings)" section below.

### SNES
Emulator is Snes9x 2005 v1.36 (Git commit [`b94a804`](https://github.com/libretro/snes9x2005/commit/b94a804)). With the April 20th version of the firmware, SNES games often appear to run very slowly _on first launch_; but if you exit the game and load it again, it usually starts performing _much_ better.

### Genesis/Mega Drive
Emulator is PicoDrive 1.91 (Git commit [`cbc93b6`](https://github.com/libretro/picodrive/commit/cbc93b6)). Works pretty well. This emulator is capable of loading Master System ROMs if placed in the user ROMs folder on the microSD card; Game Gear ROMs do not load. Some PAL-region games may run too fast; NTSC-region games seem to always run at the correct speed. On the original firmware, A was mapped to A, B was mapped to B, and RB was mapped to C for some reason. See "[Button Mappings/Key Bindings](#button-mappingskey-bindings)" section below.

### Game Boy
Emulator is TGB Dual v0.8.3 (Git commit [`9be31d3`](https://github.com/libretro/tgbdual-libretro/commit/9be31d3)). Uses a black and white colour palette, which currently cannot be changed. On the original firmware, the A and B buttons were swapped. See "[Button Mappings/Key Bindings](#button-mappingskey-bindings)" section below.

### Game Boy Color
Emulator is TGB Dual v0.8.3 (Git commit [`9be31d3`](https://github.com/libretro/tgbdual-libretro/commit/9be31d3)). On the original firmware, the A and B buttons were swapped. See "[Button Mappings/Key Bindings](#button-mappingskey-bindings)" section below.

### Game Boy Advance
Emulator is gpSP v0.91 (Git commit [`261b2db`](https://github.com/libretro/gpsp/commit/261b2db)). Performance is fairly poor. On the original firmware, A and B buttons are mapped correctly, but the GBA shoulder buttons are mapped to X and Y for some reason. See "[Button Mappings/Key Bindings](#button-mappingskey-bindings)" section below.

While the SF2000 does include a copy of the real GBA BIOS file in the `bios` folder, there's a bug in the `05.22` firmware (and possibly earlier firmwares) that prevents that BIOS from ever actually being loaded. As such, gpSP _always_ falls back to the built-in "NORMMATT" BIOS instead (a reverse-engineered BIOS that is not identical to Nintendo's one). This has been noted to have some compatibility issues - for example, the main menu on "The Legend of Zelda - The Minish Cap" is broken on a stock SF2000 using the `05.22` firmware due to the NORMMATT BIOS. You can correct for this bug by copying the `gba_bios.bin` file from the `bios` folder to the two following locations (create any folders as needed - and credit to `bnister` for the finding!):

- `GBA/mnt/sda1/bios/gba_bios.bin` (this fixes it for the main GBA game list)
- `ROMS/mnt/sda1/bios/gba_bios.bin` (this fixes it for GBA games added to the user `ROMS` folder)

### Save States
All of the above emulators support stave sates natively through an interface that is accessed by pressing SELECT + START simultaneously in-game. Four save state slots are provided per-game; the files have the extensions `.sa0`, `.sa1`, `.sa2` and `.sa3` depending on which slot they're for. The extension is appended to the name of the ROM file the save state is for; for example, if the ROM is called `Apotris.gba`, and the save state is for slot 2, then the save state file name will be `Apotris.GBA.sa1`. One weird note is that save states created for ROMs stored in the user `ROMS` folder on the device get their ROM file extension capitalised when a save state is created (as per the previous example with `Apotris`, where `.gba` became `.GBA`); this does _not_ happen with save states created in the other ROM folders. The capitalisation doesn't appear to matter - the SF2000 successfully loads save states with any extension capitalisation in any folder.

The save state files themselves contain two zlib-compressed data blobs, plus associated metadata - one blob for the raw save state data created by the emulator itself, and one blob for the thumbnail used for the save state in the UI. The exact format is as follows

* The first four bytes are a little-endian Uint32 storing the length of the zlib-compressed raw save state data
* The next N bytes are the zlib-compressed raw save state data
* The next four bytes are a little-endian Uint32 storing the width of the thumbnail image in pixels
* The next four bytes are a little-endian Uint32 storing the height of the thumbnail image in pixels
* The next four bytes are a little-endian Uint32 storing the length of the zlib-compressed thumbnail data
* The next N bytes are the zlib-compressed thumbnail data (deflates to a raw RGB565 image, much like many of the other images used by the SF2000 UI)
* The last four bytes are a little-endian Uint32 storing the offset within the file of where the thumbnail metadata starts (i.e., the offset of the first byte of width data)

If you want to mess around with SF2000 save states, you can [do so using my SF2000 Save State Tool, which you can find here](https://vonmillhausen.github.io/sf2000/tools/saveStateTool.htm).

### Default ROMs
The default full firmware for the SF2000 comes with over 6000 ROMs across the seven supported systems. The manual suggests these are for "demonstration purposes" only, and should be deleted by the owner (with any failure to do so not being their responsibility) - despite the fact that the SF2000's menus are hard-coded for this specific list of ROMs. The ROM files themselves are a custom bundle format; the first `59,904 bytes` are an RGB565 image shown as a thumbnail beside the game when selected in a game-list, and the remainder of the file is a slightly mangled/obfuscated ZIP file containing the game's single ROM file. The only exception to this format are the arcade ROMs, which consist of a plain-old Final Burn Alpha ROM zip file, coupled with a `.zfb` file containing the thumbnail image and a pointer to the ROM zip file name.

I was curious to see how the included ROMs matched up against the current "[No-Intro](https://no-intro.org/)" catalogue for each of the non-arcade systems, so I wrote a small script to extract the ROMs from the SF2000's bundles (`05.22` firmware), and compare the hashes against the current (June 9th, 2023) set of No-Intro DAT files. You can [find a big HTML file with all of the results here](/defaultRoms/defaultRomsNoIntroCheck.htm), and [a raw CSV file of the same data here](/defaultRoms/defaultRomsNoIntroCheck.csv). You can click most of the column headers in the HTML version to sort the table by that column. The NES ROMs had their first 16-bytes stripped to remove their "iNES" header (thanks for the tip, `bnister`!), and were compared against the "header-less" No-Intro NES dat file.

---

## Firmware/BIOS (bisrv.asd)
The firmware for the SF2000 is actually located on the microSD card, in a file called `bisrv.asd` located in the BIOS folder. This file is a monolithic binary blob, which contains the device's OS, the emulators, their settings... basically everything. Data Frog have issued some firmware updates for the device since launch; the updates have added new features (e.g., additional language support, favourites, history, etc.), but have also introduced bugs (e.g., some SNES games run very slowly until they are quit and launched again, etc.). Data Frog have published a YouTube video showing how to update the firmware on the device, which [you can find here](https://www.youtube.com/watch?v=j8dT2fdGfck); the video's description contains a link to where you can download the latest firmware.

Known firmware versions are currently (dates approximate):

| Date | Version | Notes |
| ---- | ------- | ----- |
| Mid-March | ? | The original firmware that shipped with the first batch of devices |
| April 20th | ? | The first official firmware update; fixed some button mappings for Genesis, added support for 15 new languages. Also partially broke SNES compatibility - many SNES games will run very slowly on first launch, but quitting and immediately re-launching the game will have it run at normal speed (normal for the SF2000, anyway) |
| May 15th | ? | Added a built-in UI for global button mapping (which is broken in several ways, mainly SNES and Genesis controls are swapped, and no support for setting Player 2 controls), added a History feature, added a Favourites feature |
| May 22nd | 1.5V | First firmware with an official version number. Fixed the SNES/Genesis swapped button mappings, and now sets Player 2 controls to be identical to Player 1 (no way to set independently). There's some evidence of undocumented emulation improvements; some GBA homebrew that was non-functional in previous firmwares now loads correctly, and some GBA titles see marginally improved performance |

Custom firmware (CFW) is currently in the very early stages of development (see [here](#is-there-any-custom-firmware)). In the meantime, the stock firmware has been investigated quite a bit; here are some findings from it:

### Bootloader Bug
The bootloader on the SF2000 (the bit of code embedded in the devices hardware; it initialises things, and kicks-off loading of the BIOS from `bisrv.asd`) has a bug, which can cause the SF2000 to lock-up with a black screen during boot if the `bios` folder has been messed with. Specifically, the bug is triggered when the `bios` folder's FAT table contains a multiple of `4` entries, or a multiple of `4` plus `1`.

If your device is currently _not_ booting, and you've modified the `bios` folder in any way (e.g., patching a new boot logo, upgrading firmware, etc.), you can attempt to get the SF2000 booting again by creating empty text files inside the `bios` folder, one at a time (this creates new FAT entries, and should get you away from numbers of entries the stock bootloader doesn't like). For example, create an empty file in the `bios` folder called "temp1.txt", put the microSD card back in the SF2000, and see if it boots. If it still doesn't, add a "temp2.txt" file to the `bios` folder, put the card back in the SF2000 and try booting again, etc..

Alternatively, `bnister` found the root cause for the bug, and has created a patch which permanently fixes it (no added files required). Below are the patching instructions.

**NOTE: While many people have already reported success with patching their bootloader, and no-one has yet reported any issues with it, this patch should be considered experimental:**

1. Ensure your SF2000 is in a state where it boots normally when turned on (displays a boot logo, proceeds to the main menu)
2. Ensure your SF2000's battery is fully charged (having the device power off during the patching process will likely "brick" it, rendering it inoperable)
3. Power off the SF2000, and remove the microSD card
4. Connect the microSD card to your computer
5. Download this zip file: [SF2000_bootloader_bugfix.zip](https://cdn.discordapp.com/attachments/1099465777825972347/1105582470990135316/SF2000_bootloader_bugfix.zip)
6. Extract the zip file; inside is a folder called `UpdateFirmware`, containing a single file called `Firmware.upk`
7. Copy the `UpdateFirmware` folder to the root of the microSD card, so that the `UpdateFirmware` folder is in the same place as the `bios` and `roms` folders
8. Eject the microSD card from your computer, and put it back in the SF2000
9. Turn the SF2000 on; you should see a message in the lower-left corner of the screen indicating that patching is taking place. The process will only last a few seconds
10. When the patching is complete, you will be taken to the main menu as usual
11. Power off the SF2000, and remove the microSD card
12. Connect the microSD card to your computer
13. Delete the `UpdateFirmware` folder (it's no longer needed)

### Button Mappings/Key Bindings
`bnister` discovered that the OS supports loading game-specific key bindings from `.kmp` files, stored in the `save` folder for each system and named after a game's ROM file (e.g., `/FC/save/Game Name.EXT.kmp`). They also discovered where in the `bisrv.asd` file the default mappings for each emulator are stored. Working with this information, `notv37` worked out what bits related to what buttons for each emulator. Using both their findings, we now have a tool which can be used to update both the global button mappings for the emulators, as well as create per-ROM mappings - you can [find this tool here](https://vonmillhausen.github.io/sf2000/tools/buttonMappingChanger.htm).

Note that the game-specific key bindings function have been removed from the May 15th firmware onwards.

### Boot Logo
When the device is powered on, a "Welcome" image is displayed for a short time before the main menu appears. This image comes from inside `bisrv.asd`, (towards the end; exact offset varies between BIOS revisions). It's a `512x200` RGB565 Little Endian raw image file, and looks like this:

![Boot Logo](/images/bootlogo.png)

The image is _actually_ displayed at half-resolution on the internal display though, `256x100`, centred in the middle of the screen. The boot logo can be changed to an arbitrary `256x100` image using a web-based tool I wrote, which you can [find here](https://vonmillhausen.github.io/sf2000/tools/bootLogoChanger.htm).

---

## Resources
The Resources folder on the microSD card contains all of the resources used by the device's firmware to construct the user interface at runtime. The following tables list the files from various firmware versions (the numbered columns, in approximate `mm.dd` format) and what they are used for, grouped by broad categories. Resolution and format given are for the latest firmware version only; details may be different for older firmwares. The icons in the firmware columns have the following meanings:

- ✨: file is new to this firmware version
- ✅: file is unchanged this firmware version
- 🚩: file is changed this firmware version
- ❌: file is removed this firmware version

### Fonts
| Filename | 03.15 | 04.20 | 05.15 | 05.22 | Description |
| -------- | ----- | ----- | ----- | ----- | ----------- |
| `Arial_cn.ttf` |  | ✨ | ✅ | ✅ | The "Arial" typeface, containing Latin, Greek, Cyrillic, Chinese, and Japanese characters. Duplicate of `yahei_Arial.ttf`, the single font file from the original firmware version |
| `Arial_en.ttf` |  | ✨ | ✅ | ✅ | The "Arial" typeface, containing Latin, Greek, Cyrillic, Armenian, Hebrew and Arabic characters |
| `Arial_jp.ttf` |  | ✨ | ✅ | ✅ | The "Arial" typeface, containing Latin, Greek, Cyrillic, Chinese and Japanese characters |
| `Arial_kr.ttf` |  | ✨ | ✅ | ✅ | The "Arial" typeface, containing Latin, Greek, Cyrillic, Chinese, Japanese and Korean characters |
| `Tahoma.ttf` |  | ✨ | ✅ | ✅ | The "Tahoma" typeface, containing Latin, Greek, Cyrillic, Armenian, Hebrew, Arabic and Thai characters  |
| `yahei_Arial.ttf` | ✨ | ✅ | ✅ | ✅ | The "Arial" typeface, containing Latin, Greek, Cyrillic, Chinese, Japanese and Korean characters |

### Images (Used)
As far as I am aware, all of the below images are actively used by the `20230515` version of the firmware; happy to take any corrections if it turns out any of them are unused! Note that while the stock theme is based around a `640x480` resolution, the actual _display_ on the SF2000 is a `320x240` one. The OS on the device uses nearest-neighbour scaling for its images, giving the stock UI a somewhat aliased appearance. If you're planning to make your own theme for the SF2000, design it for `320x240`, and then double the resolution when exporting the final images to the device for a crisper look on the internal panel. I've written a generic image tool for the SF2000 - it lets you convert SF2000-formatted images to PNG files, and lets you convert PNG or JPEG images to SF2000 formats (which may be useful if you want to theme your device); you can [find this tool here](https://vonmillhausen.github.io/sf2000/tools/genericImageTool.htm).

| Filename | Resolution | Format | 03.15 | 04.20 | 05.15 | 05.22 | Description | View |
| -------- | ---------- | ------ | ----- | ----- | ----- | ----- | ----------- | ---- |
| `aepic.nec` | 1008x164 | BGRA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Korean | [view](/images/aepic.nec.png) |
| `apisa.dlk` | 640x480 | RGB565 Little Endian | ✨ | ✅ | 🚩 | ✅ | Arcade game-list background | [view](/images/apisa.dlk.png) |
| `appvc.ikb` | 150x214 | BRGA | ✨ | ✅ | ✅ | ✅ | Game art placeholder | [view](/images/appvc.png) |
| `awusa.tax` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Thai | [view](/images/awusa.tax.png) |
| `bisrv.nec` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu (position 3) | [view](/images/bisrv.png) |
| `bttlve.kbp` | 60x144 | BGRA | ✨ | ✅ | ✅ | ✅ | Battery level indicator icons | [view](/images/bttlve.png) |
| `c1eac.pal` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | SNES game-list background | [view](/images/c1eac.png) |
| `cero.phl` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Game Boy Color game-list background | [view](/images/cero.png) |
| `certlm.msa` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | NES game-list indicator | [view](/images/certlm.png) |
| `cketp.bvs` | 640x816 | RGB565 Little Endian |  |  | ✨ | ✅ | The console selection images at the bottom of the new button mapping feature screen | [view](/images/cketp.bvs.png) |
| `d2d1.hgp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu (position 2) | [view](/images/d2d1.png) |
| `dism.cef` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu (position 1) | [view](/images/dism.png) |
| `djctq.rsd` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | SNES game-list indicator | [view](/images/djctq.png) |
| `djoin.nec` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Spanish | [view](/images/djoin.nec.png) |
| `dpskc.ctp` | 640x320 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu save-state slots (positions 1, 2, 3 and 4) | [view](/images/dpskc.png) |
| `drivr.ers` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | SNES main menu background | [view](/images/drivr.png) |
| `dsuei.cpl` | 640x480 | RGB565 Little Endian | ✨ | ✅ | 🚩 | ✅ | User ROMs main menu background | [view](/images/dsuei.cpl.png) |
| `dxdiag.bin` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Genesis/Mega Drive game-list indicator | [view](/images/dxdiag.png) |
| `dxkgi.ctp` | 1008x164 | BRGA | ✨ | ✅ | 🚩 | ✅ | User settings screen icons and labels in English | [view](/images/dxkgi.ctp.png) |
| `dxva2.nec` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Search keyboard (pressed) | [view](/images/dxva2.png) |
| `ectte.bke` | 161x126 | BRGA | ✨ | ✅ | ✅ | ✅ | Main menu icon selection box | [view](/images/ectte.png) |
| `efsui.stc` | 640x480 | RGB565 Little Endian | ✨ | ✅ | 🚩 | ✅ | Game Boy Advance game-list background | [view](/images/efsui.stc.png) |
| `esent.bvs` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Turkish | [view](/images/esent.bvs.png) |
| `exaxz.hsp` | 152x1224 | BRGA | ✨ | 🚩 | ✅ | ✅ | Main menu "Games Exist" and "Start: Open" labels for all languages | [view](/images/exaxz.png) |
| `fixas.ctp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | NES main menu background | [view](/images/fixas.png) |
| `fltmc.sta` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Game Boy game-list background | [view](/images/fltmc.png) |
| `fvecpl.ai` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Game Boy game-list indicator | [view](/images/fvecpl.png) |
| `gakne.ctp` | 576x256 | BGRA |  |  | ✨ | ✅ | A new copy of the English menu labels image, identical to older versions of `dxkgi.ctp` (which was changed entirely in `05.15`) | [view](/images/gakne.ctp.png) |
| `gkavc.ers` | 576x256 | BGRA |  |  | ✨ | ✅ | A new copy of the Chinese menu labels image, identical to older versions of `itiss.ers` (which was changed entirely in `05.15`) | [view](/images/gkavc.ers.png) |
| `gpsvc.bvs` | 392x80 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu save-state slot (position 3) | [view](/images/gpsvc.png) |
| `hctml.ers` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Arcade main menu background | [view](/images/hctml.png) |
| `hgcpl.cke` | 392x80 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu save-state slot (position 2) | [view](/images/hgcpl.png) |
| `hlink.bvs` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Search keyboard (hover) | [view](/images/hlink.png) |
| `htui.kcc` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Game Boy Color game-list indicator | [view](/images/htui.png) |
| `icm32.dll` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Game Boy Advance game-list indicator | [view](/images/icm32.png) |
| `icuin.cpl` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Genesis/Mega Drive main menu background | [view](/images/icuin.png) |
| `igc64.dll` | 217x37 | BGRA | ✨ | ✅ | ✅ | ✅ | "Yes" and "No" text, with "No" selected; used when being asked if you want to overwrite a save-game slot | [view](/images/igc64.png) |
| `ihdsf.bke` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Genesis/Mega Drive game-list background | [view](/images/ihdsf.png) |
| `irftp.ctp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Game Boy Advance main menu background | [view](/images/irftp.png) |
| `irmon.tax` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Dutch | [view](/images/irmon.tax.png) |
| `itiss.ers` | 1008x164 | BRGA | ✨ | ✅ | 🚩 | ✅ | User settings screen icons and labels in Chinese | [view](/images/itiss.ers.png) |
| `jccatm.kbp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | "Battery Empty" screen | [view](/images/jccatm.png) |
| `ke89a.bvs` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Portuguese | [view](/images/ke89a.bvs.png) |
| `kmbcj.acp` | 640x480 | RGB565 Little Endian |  |  | ✨ | ✅ | The full-screen background image for the new button mapping screen | [view](/images/kmbcj.acp.png) |
| `ksxbar.ax` | 392x80 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu save-state slot (position 4) | [view](/images/ksxbar.png) |
| `lfsvc.dll` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Search game-list background | [view](/images/lfsvc.png) |
| `lk7tc.bvs` | 52x192 | BGRA |  |  | ✨ | ✅ | Transparent labels for the button assignments in the new button mapping feature; these are the ones overlaid on the big SF2000 image showing the current assignments | [view](/images/lk7tc.bvs.png) |
| `lkvax.aef` | 640x480 | RGB565 Little Endian |  |  | ✨ | ✅ | History game-list background | [view](/images/lkvax.aef.png) |
| `mkhbc.rcv` | 640x1440 | RGB565 Little Endian |  |  | ✨ | ✅ | Six vertically-stacked images of the SF2000 with different buttons highlighted, used as part of the new button mapping feature's UI | [view](/images/mkhbc.rcv.png) |
| `mksh.rcv` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Search keyboard (normal) | [view](/images/mksh.png) |
| `msdmo.gdb` | 392x80 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu save-state slot (position 1) | [view](/images/msdmo.png) |
| `msgsm.dll` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Arcade game-list indicator | [view](/images/msgsm.png) |
| `mssvp.nec` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Japanese | [view](/images/mssvp.nec.png) |
| `normidna.bin` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Search game-list indicator | [view](/images/normidna.png) |
| `ntdll.bvs` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Polish | [view](/images/ntdll.bvs.png) |
| `nvinf.hsp` | 16x240 | BGRA | ✨ | ✅ | ✅ | ✅ | Latin numbers 0 to 9 listed vertically, used for the number of games available in each main menu category | [view](/images/nvinf.hsp.png) |
| `okcg2.old` | 32x32 | BGRA |  |  | ✨ | ✅ | The star icon that appears beside favourited games in the game-lists | [view](/images/okcg2.old.png) |
| `pcadm.nec` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Italian | [view](/images/pcadm.nec.png) |
| `pwsso.occ` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu (position 4) | [view](/images/pwsso.png) |
| `qasf.bel` | 640x480 | RGB565 Little Endian | ✨ | ✅ | 🚩 | ✅ | User game-list background | [view](/images/qasf.bel.png) |
| `qwave.bke` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Game Boy Color main menu background | [view](/images/qwave.png) |
| `rmapi.tax` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in German | [view](/images/rmapi.tax.png) |
| `sdclt.occ` | 120x240 | RGB565 Little Endian | ✨ | 🚩 | 🚩 | ✅ | TV system selection icons | [view](/images/sdclt.occ.png) |
| `sensc.bvs` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in French | [view](/images/sensc.bvs.png) |
| `sfcdr.cpl` | 576x1344 | BRGA | ✨ | 🚩 | ✅ | ✅ | Main menu system logos | [view](/images/sfcdr.png) |
| `subst.tax` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Russian | [view](/images/subst.tax.png) |
| `ucby4.aax` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Arabic | [view](/images/ucby4.aax.png) |
| `urlkp.bvs` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | NES game-list background | [view](/images/urlkp.png) |
| `uyhbc.dck` | 640x480 | RGB565 Little Endian |  |  | ✨ | ✅ | Favourites game-list background | [view](/images/uyhbc.dck.png) |
| `vidca.bvs` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Hebrew | [view](/images/vidca.bvs.png) |
| `vssvc.nec` | 1008x164 | BRGA |  | ✨ | 🚩 | ✅ | User settings screen icons and labels in Malay | [view](/images/vssvc.nec.png) |
| `wshrm.nec` | 217x37 | BGRA | ✨ | ✅ | ✅ | ✅ | "Yes" and "No" text, with "Yes" selected; used when being asked if you want to overwrite a save-game slot | [view](/images/wshrm.png) |
| `xajkg.hsp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Game Boy main menu background | [view](/images/xajkg.png) |
| `ztrba.nec` | 64x320 | RGB565 Little Endian |  |  | ✨ | ✅ | Non-transparent labels for the button assignments in the new button mapping feature; these are the ones that pop up when you go to change a button assignment | [view](/images/ztrba.nec.png) |

### Images (Unused)
To the best of my knowledge, the following image files are currently __unused__ by the `20230515` firmware, and were probably left over from previous devices (the SF2000 shares a bit of lineage with some USB-stick devices) or development. The images marked "Alternate UI" below appear to have been for a UI where the systems were scrolled through horizontally, and the "shortcut" games for each system were scrolled vertically.

| Filename | Resolution | Format | 03.15 | 04.20 | 05.15 | 05.22 | Description | View |
| -------- | ---------- | ------ | ----- | ----- | ----- | ----- | ----------- | ---- |
| `aeinv.bke` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Genesis/Mega Drive main menu background | [view](/images/unused/aeinv.bke.png) |
| `aepic.ers` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: User main menu background | [view](/images/unused/aepic.ers.png) |
| `c1e.pal` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | CPS2 game-list background | [view](/images/unused/c1e.pal.png) |
| `cca.bvs` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu (position 1; Chinese language hardcoded) | [view](/images/unused/cca.bvs.png) |
| `dectMap.key` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Button test screen (active) | [view](/images/unused/dectMap.key.png) |
| `desk.cpl` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Eight-game selection screen | [view](/images/unused/desk.cpl.png) |
| `djoin.hsp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Arcade main menu background | [view](/images/unused/djoin.hsp.png) |
| `fcont.ctp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: User main menu background | [view](/images/unused/fcont.ctp.png) |
| `fdbil.ph` | 1100x120 | BGRA | ✨ | ✅ | ✅ | ✅ | Large icons for each system, including systems not supported by the SF2000 (selected) | [view](/images/unused/fdbil.ph.png) |
| `gpapi.bvs` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | In-game menu (position 5; looks like it was for some kind of button layout changing UI) | [view](/images/unused/gpapi.bvs.png) |
| `ihds.bke` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Genesis/Mega Drive game-list background, with baked-in thumbnail placeholder | [view](/images/unused/ihds.bke.png) |
| `kdill.hsp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Game Boy Advance main menu background | [view](/images/unused/kdill.hsp.png) |
| `logilda.be` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | CPS1 game-list indicator | [view](/images/unused/logilda.be.png) |
| `mfc64.emc` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | CPS2 game-list indicator | [view](/images/unused/mfc64.emc.png) |
| `mfpmp.ers` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Arcade main menu background | [view](/images/unused/mfpmp.ers.png) |
| `mhg4s.ihg` | 400x192 | RGB565 Little Endian |  |  | ✨ | ✅ | Background and buttons for a "warning" prompt with "OK", "Yes" and "No" buttons. Also has rounded edges stored in a separate image file, `zaqrc.olc` | [view](/images/unused/mhg4s.ihg.png) |
| `mrtac.klo` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Neo Geo game-list indicator | [view](/images/unused/mrtac.klo.png) |
| `msdtc.bke` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Game Boy Advance main menu background | [view](/images/unused/msdtc.bke.png) |
| `mswbv.cpl` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Game Boy Advance main menu background | [view](/images/unused/mswbv.cpl.png) |
| `nettrace.dll` | 40x24 | BGRA | ✨ | ✅ | ✅ | ✅ | Unknown game-list indicator (grey joystick with yellow buttons) | [view](/images/unused/nettrace.dll.png) |
| `nsibm.ctp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Arcade main menu background | [view](/images/unused/nsibm.ctp.png) |
| `nvinfohsp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Genesis/Mega Drive main menu background (note: there's no extension separator for this file, I suspect the file name is typo'd in the filesystem!) | [view](/images/unused/nvinfohsp.png) |
| `pcadm.hsp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: User main menu background (NTSC TV system selected) | [view](/images/unused/pcadm.hsp.png) |
| `plasy.ers` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Game Boy Advance main menu background | [view](/images/unused/plasy.ers.png) |
| `rmapi.cpl` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: User main menu background (English UI language selected) | [view](/images/unused/rmapi.cpl.png) |
| `seltMap.key` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Button test screen | [view](/images/unused/seltMap.key.png) |
| `spmpm.gdp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: NES game-list background, with baked-in thumbnail placeholder | [view](/images/unused/spmpm.gdp.png) |
| `subst.bke` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Arcade main menu background | [view](/images/unused/subst.bke.png) |
| `tsmcf.cpl` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Alternate UI: Arcade main menu background | [view](/images/unused/tsmcf.cpl.png) |
| `url.bvs` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | CPS1 game-list background | [view](/images/unused/url.bvs.png) |
| `werui.ioc` | 320x240 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | "NODATA" save-state thumbnail placeholder image, with a "horror" style typeface | [view](/images/unused/werui.ioc.png) |
| `wshom.ocx` | 1100x120 | BGRA | ✨ | ✅ | ✅ | ✅ | Large icons for each system, including systems not supported by the SF2000 (normal) | [view](/images/unused/wshom.ocx.png) |
| `x86e.hgp` | 640x480 | RGB565 Little Endian | ✨ | ✅ | ✅ | ✅ | Neo Geo game-list background | [view](/images/unused/x86e.hgp.png) |
| `zaqrc.olc` | 8x224 | BGRA |  |  | ✨ | ✅ | Rounded ends that pair with the warning dialogue stored in `mhg4s.ihg` | [view](/images/zaqrc.olc.png) |

### Other Files
These are other files that have been identified, which don't fit into the other categories. Non-Latin characters in the files are encoded in UTF-8.

| Filename | 03.15 | 04.20 | 05.15 | 05.22 | Description |
| -------- | ----- | ----- | ----- | ----- | ----------- |
| `Archive.sys` | ✨ | 🚩 | ✅ | ✅ | Stores the settings for UI language and TV system. Two 32-bit words (4-bytes), little endian. The first is UI language; `0x00000000` is English, `0x01000000` is Chinese, etc.. The second is the TV system setting; `0x00000000` is NTSC, `0x01000000` is PAL. Note the "🚩" icon here indicates the format of the data, or the permissible values were changed (as opposed to the data itself, which will vary from device to device based on user settings) |
| `bfrjd.odb` |  | ✨ | 🚩 | ✅ | UI strings in Korean |
| `bxvtb.sby` |  | ✨ | 🚩 | ✅ | UI strings in Thai |
| `dufdr.cwr` |  | ✨ | 🚩 | ✅ | UI strings in Turkish |
| `eknjo.ofd` |  | ✨ | 🚩 | ✅ | UI strings in Spanish |
| `Favorites.bin` |  |  | ✨ | ✅ | Used to store the list of ROMs added to the Favorites list; only appears after the first game is favourited after installing the 05.15 or later firmware. User ROMs cannot be added to favourites, only built-in games |
| `fhshl.skb` | ✨ | ✅ | 🚩 | ✅ | UI strings in English |
| `Foldername.ini` | ✨ | 🚩 | 🚩 | ✅ | Used to control menu rotation for the main menu; see below for more notes on this |
| `History.bin` |  |  | ✨ | ✅ | Used to store the history of played ROMs; only appears after the first game is played after installing the 05.15 or later firmware. User ROMs are not added to history, only built-in games. If a built-in game that is referenced in history is removed from the device, the device will crash when trying to view the History screen. You can delete the History.bin file to clear the device's history; there is no built-in functionality to do so |
| `jsnno.uby` |  | ✨ | 🚩 | ✅ | UI strings in Dutch |
| `kcbn7.avc` |  | ✨ | ❌ |  | Duplicate copy of `bisrv.asd`, the main firmware for the device which is found in the BIOS folder  |
| `KeyMapInfo.kmp` |  |  | ✨ | ✅ | Used to store the user-assignable global button mappings for each emulated system |
| `lf9lb.cut` |  | ✨ | 🚩 | ✅ | UI strings in Portuguese |
| `ntrcq.oba` |  | ✨ | 🚩 | ✅ | UI strings in Japanese |
| `ouenj.dut` |  | ✨ | 🚩 | ✅ | UI strings in Polish |
| `qdbec.ofd` |  | ✨ | 🚩 | ✅ | UI strings in Italian |
| `sgotd.cwt` |  | ✨ | 🚩 | ✅ | UI strings in French |
| `snbqj.uby` |  | ✨ | 🚩 | ✅ | UI strings in German |
| `t2act.sgf` | ✨ | ✅ | 🚩 | ✅ | UI strings in Chinese |
| `Test.zsf` |  | ✨ | ❌ |  | A SNES ROM, which displays a controller test program |
| `tvctu.uby` |  | ✨ | 🚩 | ✅ | UI strings in Russian |
| `vdaz5.bjk` |  | ✨ | 🚩 | ✅ | UI strings in Arabic |
| `wtrxj.lbd` |  | ✨ | 🚩 | ✅ | UI strings in Malay |
| `xjebd.clq` |  | ✨ | 🚩 | ✅ | UI strings in Hebrew |

#### Foldername.ini
This file controls some of the UI settings for the main menu. It's a plain-text file, but not an actual INI file. It's contents from the `05.22` firmware (just as an example) are as follows:

```
SF2000
17
FFFFFF
FF8000 ROMS
FF8000 FC
FF8000 SFC
FF8000 MD
FF8000 GB
FF8000 GBC
FF8000 GBA
FF8000 ARCADE
FF8000 ROMS
FF8000 ROMS
8 7 0
24 184 144 208
40 24


```

And here's my current understanding of what each line is used for:

- `SF2000`: The name of the device; I don't believe it's actively used anywhere, please correct me if I'm wrong!
- `17`: The number of languages supported by the firmware
- `FFFFFF`: Hexadecimal colour (RGB) for the general game-list texts, and the `x/yyy` game count in the top-right corner of each game-list
- `FF8000 ROMS`: The first defined main menu section (the sections that are scrolled vertically on the main menu). Internally they are numbered from 0; so the `ROMS` section (user ROMs and settings) is 0, `FC` (NES) is 1, `SFC` (SNES) is 2, etc.. The `FF8000` is the hexadecimal colour (RGB) to display the text of the currently selected/highlighted game in the list; the default colour is orange. _Side note:_ after the `ARCADE` section, there's two additional `ROMS` sections; the firmware is hard-coded to have ten sections. The SF2000 appears to share its firmware with other similar devices, and some of those devices feature different menu sections (e.g., "CPS1", "Neo Geo", etc.). I suspect that the best of those systems has ten sections in its main menu, which doesn't match up with the eight sections on the SF2000 (seven supported systems + the user ROMs/settings section). As the firmware requires ten sections to be defined, they just repeated the `ROMS` section to fill in the remaining places. Like I say, that's just a guess!
- `8 7 0`: This is used to control the main menu rotation. `8` tells the firmware how many main menu sections are actually in-use on this device; for the SF2000 that's seven supported consoles + the user ROMs/settings section, for eight total. `7` tells the firmware which menu section to default to when the device boots up, which is why by default it always starts in the `ARCADE` section. `0` tells the firmware which section to display the special "user settings" menu on (the one with History, Favourites, TV System, Language, etc.). So for example, if you wanted the SF2000 to start up on the user ROMs/settings screen instead of Arcade, you could change this line to read `8 0 0`
- `24 184 144 208`: These numbers control the position and size of the game artwork in each system's game-list. The first two numbers are the X and Y coordinates from the top-left corner of the screen for where to start drawing the artwork; the second two numbers are the width and height of the artwork to draw. Note that the SF2000 doesn't do any image scaling; the dimensions are for the rectangular area the device will begin adding each pixel of the source artwork to. If the artwork's dimensions don't exactly match the dimensions specified here, the artwork will not display properly
- `40 24`: The width and height of the icon shown beside the currently selected/highlighted game in a game-list. Again, these are the dimensions of the rectangular area the SF2000 draws the pixel data into, so if these numbers don't match the dimensions of the list indicator image, the image will not display properly

NOTE: While the text colours above work just fine with the SF2000 _first_ boots up, after loading a game and returning to the menu the general game-list/game count colour reverts to an off-white colour, and is likely being pulled from inside the BIOS somewhere. Also note that currently there is no way to choose a highlight colour for the Favourites or History sections - those are fixed at the stock orange colour (FF8000), and are almost certainly hardcoded in the BIOS as well.

#### Favourites and History
The `Favorites.bin` and `History.bin` files above both share the same file structure:

* The first 4 bytes are a little-endian Uint32 storing the number of entries in the list
* The rest of the file is composed of pairs of 2 byte little-endian Uint16s - the first byte pair is a number indicating which ROM list the entry belongs to (more on that below); the second number is the 0-based game number within that list

The ROM lists are numbered as follows:

| Number | ROM List | List File |
| ------ | -------- | --------- |
| 1 | NES | `rdbui.tax` |
| 2 | SNES | `urefs.tax` |
| 3 | Genesis/Mega Drive | `scksp.tax` |
| 4 | Game Boy | `vdsdc.tax` |
| 5 | Game Boy Color | `pnpui.tax` |
| 6 | Game Boy Advance | `vfnet.tax` |
| 7 | Arcade | `mswb7.tax` |

So, for example: if your most recently played game (first in the history list) was "Batman - The Video Game" for Game Boy, and that game happened to be the ninth game listed in the Game Boy section on your device, the fifth and sixth bytes in your `History.bin` would be `0x04 0x00` (which is `4` in decimal, i.e. the "Game Boy" ROM list), and the seventh and eighth bytes would be `0x08 0x00` (which is `8` in decimal, i.e. the 9th game in the 0-based list of Game Boy games). The `Favorites.bin` file works exactly the same way, just with games you've favourited rather than played recently.

For more information on the ROM lists in general, see the next section.

### ROM Lists
Credit for this section goes to `taizou`, author of [FROGTOOL](https://github.com/tzlion/frogtool). These files relate to the built-in game-lists under each main system; the list of games is pulled from these files instead of being built at runtime - annoying, but presumably for performance reasons. It means if you want to change the list of built-in games (instead of using the User ROMs section), you have to edit these files - hence FROGTOOL, you should really check it out. There is also a tool called [Tadpole](https://github.com/EricGoldsteinNz/tadpole) by `.ericgoldstein` which provides a GUI for FROGTOOL along with some additional features.

| Files | Description |
| ----- | ----------- |
| `mfpmp.bvs` (Arcade), `mgdel.bvs` (Game Boy Color), `nethn.bvs` (NES), `qdvd6.bvs` (Game Boy), `sppnp.bvs` (Game Boy Advance), `wmiui.bvs` (Genesis/Mega Drive), `xvb6c.bvs` (SNES) | Pinyin translations of the English ROM names, used for Chinese language searching. Not all game names are translated |
| `adsnt.nec` (SNES), `fhcfg.nec` (NES), `htuiw.nec` (Game Boy Advance), `msdtc.nec` (Arcade), `setxa.nec` (Genesis/Mega Drive), `umboa.nec` (Game Boy), `wjere.nec` (Game Boy Color) | Chinese translations of the English ROM names, used to display the game-lists when the UI language is set to Chinese. Not all game names are translated |
| `mswb7.tax` (Arcade), `pnpui.tax` (Game Boy Color), `rdbui.tax` (NES), `scksp.tax` (Genesis/Mega Drive), `urefs.tax` (SNES), `vdsdc.tax` (Game Boy), `vfnet.tax` (Game Boy Advance) | English ROM Names, used to display the game-lists when the UI language is set to English |
| `xfgle.hgp`, `xfgle.hgp.bak` | The `xfgle.hgp` file is a plain-text file containing the ROM "shortcuts" on the main menu for each game system. The `xfgle.hgp.bak` file appears to be a test version of this file that was not removed from the firmware before being sent to production |
| `TSMFK.TAX` | This is a ROM list file similar to the other `.tax` files, except it is built at run-time from the ROM files in the user roms folder. The file is regenerated each time the device boots |

### Sounds
There are several sound files in the `20230420` firmware, stored in raw signed 16-bit PCM format (mono, little-endian at 22050 Hz). The SF2000 seems to play the files back at an incorrect sample rate vs. the raw data; if you want to customise the background music, resample your audio to 21560 Hz (21561.1 Hz is technically precise, but 21560 Hz is easer to remember, and all but the most exacting of human ears is unlikely to detect the difference), and then speed the audio up to 22050 Hz, using the resulting audio as the raw data (credit to `notv37` in Discord for doing the initial discovery math, and to `bnister` for doing technical follow-up in the firmware - you can [read their deep-dive into the details here](https://discord.com/channels/741895796315914271/1099465777825972347/1112643797344583710) (Discord link)).

If you want to do it using [Audacity](https://www.audacityteam.org/) , the steps are:

1. Open your audio file
2. Click the "Audio Setup" button on the top toolbar, choose "Audio Settings..."
    * Set "Project Sample Rate" to "22050 Hz"
    * Click "OK"
3. Click the "Select" button in the lower-left corner of your audio track area to select all the audio
4. If your track is stereo, down-mix to mono: "Tracks" menu > "Mix" > "Mix Stereo Down to Mono"
5. "Tracks" menu > "Resample..."
    * Set "New sample rate (Hz)" to "22050"
    * Click "OK"
6. "Effect" menu > "Pitch and Tempo" > "Change Speed..."
    * Set "Speed Multiplier" to "1.023"
    * Click "Apply" (your audio will now sound slightly too high-pitched if you play it back, but don't worry - the SF2000 plays everything slightly slow/low-pitched, so we speed/pitch things up before exporting so it plays back correctly)
7. "File" menu > "Export" > "Export Audio..."
    * Set "Save as type" to "Other uncompressed files"
    * In "Format Options", set "Header" to "RAW (header-less)"; set "Encoding" to "Signed 16-bit PCM"
    * Enter your "File name", and click "Save"
    * If the "Edit Metadata Tags" window appears, just leave everything blank and click "OK"

| Filename | 03.15 | 04.20 | 05.15 | 05.22 | Description | Listen |
| -------- | ----- | ----- | ----- | ----- | ----------- | ------ |
| `c2fkec.pgt` | ✨ | ✅ | 🚩 | ✅ | "Popping" sound that is played when moving around the search keyboard | [listen](/sounds/c2fkec.pgt.mp3) |
| `dpnet.dll` | ✨ | ✅ | ✅ | ✅ | "Downwards Zap" sound, unknown usage | [listen](/sounds/dpnet.dll.mp3) |
| `dsreg.bvs` | ✨ | ✅ | ✅ | ✅ | "Upwards Bleeping" sound, unknown usage | [listen](/sounds/dsreg.bvs.mp3) |
| `help.lis` | ✨ | ✅ | ✅ | ✅ | "Double Buzzer" sound, unknown usage | [listen](/sounds/help.lis.mp3) |
| `mfsvr.nkf` | ✨ | ✅ | 🚩 | ✅ | "Beep" sound that is played when entering a letter on the search keyboard | [listen](/sounds/mfsvr.nkf.mp3) |
| `nyquest.gdb` | ✨ | ✅ | 🚩 | ✅ | "Whooshing" sound that is played when switching between emulated systems on the main menu, between the "Resume", "Quit", "Load" and "Save" options on the in-game menu, and scrolling by pages within a system's game-list | [listen](/sounds/nyquest.gdb.mp3) |
| `oldversion.kbe` | ✨ | ✅ | 🚩 | ✅ | "Three Note Upward Chime" sound that is played when deleting a letter on the search keyboard | [listen](/sounds/oldversion.kbe.mp3) |
| `pagefile.sys` | ✨ | ✅ | 🚩 | ✅ | Main menu background music. If you don't like background music, and would rather just have silence, you can [find a replacement silent `pagefile.sys` here](/sounds/silentMusic/pagefile.sys) - just replace the one in the `Resources` folder (don't forget to backup the original file first, in case you ever want that jaunty tune again!) | [listen](/sounds/pagefile.sys.mp3) |
| `swapfile.sys` | ✨ | ✅ | ✅ | ✅ | "Squishy" sound played when navigating horizontally through "shortcut" games on the main menu, or vertically within a system's game-list | [listen](/sounds/swapfile.sys.mp3) |

### Unknown Files
These are files that I have not yet determined what they do; if anyone has any information on these, do post about it in the Data Frog channel in the Retro Handhelds Discord server please!

| Filename | 03.15 | 04.20 | 05.15 | 05.22 | Description |
| -------- | ----- | ----- | ----- | ----- | ----------- |
| `kcnuv.lit` | ✨ | ✅ | ✅ | ✅ | UNKNOWN; a bunch of 4-byte binary chunks (e.g., `0xC4 0x00 0x00 0x00`), followed by a list of .NES ROM file names. Very similar to the `.bvs`/`.nec`/`.tax` files detailed above, but doesn't have the same type of "header" they have |

### Notes For Theme Creators
This section isn't really about the `Resources` files per-se, but it's tangentially related. The fact that the SF2000's UI resources are pulled from the microSD card opens up the door to "theming" the device, which is great. However, if you do decide you want to make a theme for the SF2000, here's a few things I've found that you may want to bear in mind:

- If you're including background music in your theme, note that when the SF2000 starts up it fails to output about the first 1 second of audio; therefore, if you'd like the person using your theme to hear your background music from the start, cut one second off the end of your background music loop, and move it to the start of the loop instead.
- If you're creating custom system logos (`sfcdr.cpl`), make sure the logos don't overlap the "Games Exist" image's screen area (`exaxz.hsp`, top-left coordinate `456, 88`, width and height `152, 72`); the main menu compositor clips an area of the section's _background_ image behind where the "Games Exist" artwork will be drawn, renders the "Games Exist" artwork into that clipped section, and then draws the result _on top_ of the system logo. As a result, any pixels of the system logo that should be visible in that area will be replaced by the background image, even if you make the "Games Exist" image fully transparent. Removing the `exaxz.hsp` file entirely doesn't work either, as you get garbage drawn on the screen in the same area instead. The only section not impacted by this is the "User ROMs and Settings" section, as on that screen the "Games Exist" artwork is not drawn.
  - There's a workaround, but it's not perfect: you can bake a system's logo directly into the background for its main-menu section, and make it's portion of `sfcdr.cpl` fully transparent (so that you don't see the logo physically moving). As the code for drawing the "Games Exist" image pulls from the section's background, it'll pull the portion that overlaps with the system logo and render that too. The _downside_ is that the poor draw code of the stock OS only updates the horizontal portion of the screen that contains the rotating logos during section transitions, and only draws the lower portion of the screen (the bit under the rotating logos) afterwards. So baking your logo into background for the section will create some artificial "latency" for the theme user - they'll see the new logo appear instantly, then have to wait the quarter second for the invisible "rotation" animation to complete, before the lower portion of the screen with the new shortcuts for the new section appears.
  - One _other_ workaround (that's even worse than the first workaround): bake just the portion of the system logo that overlaps with `exaxz.hsp` into the background. Doing it this way, you can still have your custom system logo in `sfcdr.cpl`, and still have it in the rotation animation (which gives the user something to look at, and reduces that fake "latency" feeling from the workaround above)... but you'll see the bit of logo baked into the background appear instantly, and then the rotating logo will slide up/down to meet it, so it'll still look a bit janky. So really it comes down to picking your particular flavour of jank: scaling your logos to avoid the `exaxz.hsp` screen area (which might leave you with a lot of empty space), baking your logo into the section background (adding fake "latency" to the experience), or only partially baking your logo into the section background (which will make things look jank during the rotation animation, but perfect otherwise)... the decision is yours!
- When designing your theme, think carefully about the use case in which you want your theme to look best. Although the SF2000 uses many different UI images at many different scales, internally the screen area it draws to is `640 x 480` pixels in size. However, the actual physical display is only `320 x 240`; as the SF2000's OS does not do any image resampling when downscaling its UI output to the screen, what essentially happens is every second row and column of pixels is thrown away - and as a result, a theme designed for the internal `640 x 480` resolution can look a bit aliased or "jagged" on the internal display. If you want your theme to look pixel-perfect on the internal display, design it for `320 x 240` instead (i.e., for any image asset you create, design and create it at half of the original resolution of the same file in the stock SF2000 theme), and perform a nearest-neighbour upscale of the image back to the original resolution when converting it to an SF2000 data format. The resulting images will be pixel perfect on the internal display. _HOWEVER... there is one major downside to do thing this_: AV output. When using the AV output of the SF2000, it does so at 576i - higher than the resolution of the internal display. If you're using a theme that was scaled up from a `320 x 240` design base, you can clearly see pixelisation of the UI assets on the external display; a `640 x 480` based theme displays smooth assets. So what if you want to design a theme that looks decently sharp (not aliased) on the internal display, _and_ looks decently smooth on an external display, then design your theme for three-quarters resolution (`480 x 360` design base), and do a bilinear upscale to `640 x 480` based resolutions during final data conversion. To summarise:
  - If you only care about how your theme looks on the internal display, and don't care about how it looks on AV output, design for a `320 x 240` base resolution and do a **nearest-neighbour** 2x upscale when converting to SF2000 formats
  - If you only care about how your theme looks via AV out, and don't care about it looking aliased/jagged on the internal display, design for the regular `640 x 480` base
  - If you care about both display types, and want your theme to look great (but not perfect) on both, design for a three-quarters `480 x 360` base, and do a **bilinear** upscale to regular `640 x 480` base resolutions when converting to SF2000 formats

---

## Tools and Links
All of these are linked above already in their relevant sections, but just in case you prefer to see them as a pulled-out list, here they are again:

- [BIOS CRC32 Patcher](https://vonmillhausen.github.io/sf2000/tools/biosCRC32Patcher.htm)
- [`bnister`'s Bootloader Patch](#bootloader-bug)
- [Boot Logo Changer](https://vonmillhausen.github.io/sf2000/tools/bootLogoChanger.htm)
- [Button Mapping Tool](https://vonmillhausen.github.io/sf2000/tools/buttonMappingChanger.htm)
- [Community DataFrog SF2000 Compatibility List](https://docs.google.com/spreadsheets/d/19TCedWEKFXlnS2dlmLxk1BcnlHrX-MSVrKwEURuiU0E/edit#gid=1327539659)
- [Data Frog's firmware update tutorial](https://www.youtube.com/watch?v=j8dT2fdGfck)
- [FROGTOOL](https://github.com/tzlion/frogtool) (for updating the built-in game lists)
- [Generic Image Tool](https://vonmillhausen.github.io/sf2000/tools/genericImageTool.htm)
- [`ignatzdraconis`'s Gitlab Repo](https://git.maschath.de/ignatz/hcrtos)
- [Main Menu Icon Editor Tool by Zerter](https://zerter555.github.io/sf2000-collection/mainMenuIcoEditor.html)
- [Save State Tool](https://vonmillhausen.github.io/sf2000/tools/saveStateTool.htm)
- [SF2000 Theme Compilation Page](https://zerter555.github.io/sf2000-collection/)
- [Silent background music file](/sounds/silentMusic/pagefile.sys) (replace the file in the `Resources` folder on the microSD card)
- [Tadpole](https://github.com/EricGoldsteinNz/tadpole) (a GUI and additional features for FROGTOOL)

---

## Version History
- `20230720 - 1.29`: Another custom firmware FAQ update (a second core, gpSP, has now been compiled and is at an early stage of running).

- `20230719 - 1.28`: Moved most of the intro section under the "Is this thing any good?" FAQ, and slightly reworded parts of it. Fixed a few typos.

- `20230718 - 1.27`: Updated FAQ about custom firmware with latest details (first running Retroarch core! 🎉)

- `20230714 - 1.27`: Updated FAQ about custom firmware with latest details (Retroarch input driver in basic functional state)

- `20230712 - 1.26`: Updated FAQ about custom firmware with latest details (Retroarch video driver is now able to display the main menu!)

- `20230710 - 1.25`: Added link to `Zerter#4954`'s new main menu icon editor tool.

- `20230709 - 1.24`: Updated FAQ about custom firmware with latest details (initial Retroarch build! 🎉)

- `20230705 - 1.23`: Updated FAQ about custom firmware with latest details. Moved "what can I do" bullet point about custom themes to its own separate FAQ to make it easier to find, and added more details about how to actually _install_ a theme.

- `20230630 - 1.22`: Added a FAQ about save games not working.

- `20230626 - 1.21`: Added a FAQ about slow SNES games. Updated details of CFW development with the latest status. Added a link to the discovered SDK. Added a link to `Zerter#4954`'s new theme collection site. Added a link to the Tadpole tool by `.ericgoldstein`.

- `20230622 - 1.20`: Added a note to the Game Boy Advance section about the newly discovered `gba_bios.bin` loading bug, and how to work around it (thanks `bnister`!)

- `20230618 - 1.19`: Added a question to the FAQ regarding how to change the main menu shortcuts.

- `20230617 - 1.18`: Added an FAQ. Added a section about the bootloader bug, along with steps for installing `bnister`'s patch. Added a link to `ignatzdraconis`'s Gitlab Repo. Some folks have updated their Discord handles to Discord's new naming convention, and those handles have been updated throughout.

- `20230609 - 1.17`: Added a section about the default ROMs that come with the SF2000, including a HTML file and a CSV file that have the SHA256/SHA1/MD5/CRC32 hashes for all non-arcade ROMs, and details about which ROMs match the current No-Intro database.

- `20230605 - 1.16`: Added my new [Save State Tool](https://vonmillhausen.github.io/sf2000/tools/saveStateTool.htm). Added documentation to the Emulators section about the save state files and their format. Also added a note specifically to the Arcade section about the `.skp` files (which are secretly just save state files with a different extension). Added a "Favourites and History" section detailing the format of the `Favorites.bin` and `History.bin` files.

- `20230530 - 1.15`: Added link to the community ROM compatibility list. Added some personal notes for theme creators.

- `20230529 - 1.14`: Updated the main menu BGM sample rate details with the latest findings from `bnister`. Clarified which menu text colour resets after exiting a game. Added a note about charging safety (thanks for your sacrifices, `Zerter#4954`! 🫡)

- `20230526 - 1.13`: Updated Audacity instructions to support latest version of Audacity. Added a BIOS CRC32 patcher tool for the reckless and brave. Added a note about `Foldername.ini` text colours reverting after loading a game (thanks `Zerter#4954`!)

- `20230525 - 1.12`: Added a section about the internals of the `Foldername.ini` file. Added a note to the Arcade section about the "inrom" column in `adcockm`'s metadata document. Added a small firmware note for the `05.22` about community-spotted GBA performance improvements. Added specific emulator versions and Git commit links for each emulator (thanks `bnister` and `notv37`!). Added specific steps for producing SF2000-format audio files using Audacity.

- `20230524 - 1.11`: Added my new [Generic Image Tool](https://vonmillhausen.github.io/sf2000/tools/genericImageTool.htm). Added more exceptional information from `adcockm` in regards to arcade emulation on the SF2000, and cleaned up the old info accordingly. Corrected some typos related to `bisrv.asd` (thanks `luke7352`!). Usage of `nvinf.hsp` was tracked down to the numbers of games available on the main menu pages (thanks `kid_sinn#9691`!).

- `20230522 - 1.10`: Updated resource tables for the new `05.22` firmware (no changes); added a table with details about known firmware versions. Added a "Tools & Links" section.

- `20230516 - 1.9`: Updated most of the Resources file lists to include firmware-related information (added, (un)changed, removed). Added new image resources for the latest May 15th firmware. Updated some images files previews to contain the fake name extensions as well. Added detail about the removal of per-game button maps from May 15th firmware. Renamed the sound previews to contain the fake name extensions as well.

- `20230513 - 1.8`: Discovered two "unused" images (the yes/no buttons) are indeed actually used, when being asked if you want to overwrite a saved game. Fixed a few typos. Changed formatting of file names used throughout. A bit more info on A/V out.

- `20230512 - 1.7`: Added a note about stock battery runtime. Added a section with information about A/V output performance. Added a bit of info about PAL/NTSC region speed for Genesis/Mega Drive. Retitled the "bisrv.asd" section to make it clearer that's the BIOS/firmware. 

- `20230511 - 1.6`: Added a quick note about the display panel to the Hardware section, and added a new section for Emulators, including an incredible collection of ROM notes for Arcade thanks to `adcockm`! Also added a "silent" background music file for download, and a table of contents (this page is getting fairly long 😅). Added a `favicon.ico` to get rid of that one annoying console error.

- `20230510 - 1.5`: Added additional detail to the Hardware section about the buttons, d-pad, thumb-stick, battery, and wireless controller support.

- `20230510 - 1.4`: Added my own version of `bnister`'s button mapping tool at their request, and changed the link in the Key Mapping section accordingly.

- `20230509 - 1.3`: Added more details about how the boot logo ends up scaled on the screen, as well as a link to a new tool I wrote for altering the logo. Corrected one small formatting error.

- `20230508 - 1.2`: Added details for `Archive.sys` - thanks to `bnister` for the hints on what it related to!

- `20230507 - 1.1`: Some "unknown" files from the `Resources` folder identified with `taizou`'s help (thanks!); moved them to the Sounds and Rom Lists sections with details. Only two files left!

- `20230507 - 1.0`: Original creation of this page.