Console Observatory 0.6.0: explore by selecting, with a detailed hardware reference

Select something in the running Game Boy and learn what it is, how it works,
and how it connects to the rest of the machine. Selection info replaces
the guided tutorials and works with every ROM, including both original
bundled examples.

What's new

• Detailed contextual information for memory, registers, flags, sprites,
  tiles, map cells, system components, cartridge banks, and captured writes.
  The panel follows the most recent selection and separates observed values
  from the general explanation.
• 38 linked hardware topics covering the memory map and each region,
  instruction/register/stack basics, cartridge banks and saves, graphics,
  palettes, scrolling, windows, DMA, input, interrupts, timers, audio, serial,
  boot mapping, and the times and limits of inspection. Each article explains
  the mechanism, its use in games, and how to read the inspector.
• Background and window map views: inspect either 32×32 map or the map
  selected by LCDC. Click a cell to follow its storage byte and resolved tile
  pattern, including signed addressing. These are current-storage
  reconstructions, with their limits clearly labeled.
• Related links, topic browsing, and Back/Forward reading history.
  Execution updates the small facts label without resetting the article or
  its scroll position. Reading never starts a tutorial or replaces your ROM.
• F1 restores Selection info. Reading navigation keeps arrow keys for the
  reader; the game controls still work in the other inspectors.

The star and bank-switching examples remain playable from File → Bundled
examples. There are no guided-step controls or automatically held demo inputs.
Save-safety and inspection fixes from 0.5.0 are retained.

Download

Platform	File	Run
Windows 10/11 x64	console-observatory-0.6.0-windows-x64.zip	Unzip and run console-observatory.exe.
Ubuntu 24.04 x86-64	console-observatory_0.6.0_amd64.deb	sudo apt install ./console-observatory_0.6.0_amd64.deb

SHA256SUMS.txt contains package checksums. The Windows package is unsigned.
No commercial game or proprietary boot ROM is included. Normal use is offline.

The release workflow builds both packages from one commit and publishes only
after native tests, Linux AddressSanitizer checks, packaging, and the clean
Windows packaged launch succeed. Detailed evidence is in docs/VERIFICATION.md.

Scope

Original monochrome Game Boy (DMG), native Qt Widgets. Map/tile views use
current storage, not historical pixel provenance. Audio playback, replay,
save states, Game Boy Color mode, and link-cable sessions remain unimplemented.

Console Observatory 0.5.0: safer battery saves, steadier lessons and inspectors

Console Observatory is a native desktop Game Boy teaching lab. Run a game, pause it at any moment, and follow what happens in the CPU, memory, and graphics hardware.

What's new

Your game saves are safer

• A damaged or unrecognised .sav file is never loaded half-way and never overwritten automatically. The Cartridge panel says it is protected, and File › Save battery RAM as… lets you keep new progress somewhere else.
• If a save can't be written (for example, a read-only folder), the Cartridge panel shows the error with Save now / retry and Save elsewhere. Closing the app or opening another game then asks you first: save elsewhere, discard the unsaved progress, or cancel and keep playing.
• Saves made by other emulators with a real-time clock (older SameBoy, VBA, BGB formats) load correctly. Malformed ones are rejected safely; one such case could previously make the emulator core read past the end of the file data.
• Autosave now also runs while paused, so progress made by stepping is kept too. Restart keeps track of unsaved progress.

Inspectors you can trust in more situations

• Fixed: after about 37 minutes of continuous running, the timing calculation overflowed.
• On cartridges with several RAM banks, "last writer" now finds the write to this bank's byte, not the same address in another bank.
• Cartridge facts now follow the emulator exactly for unusual headers (multicarts, contradictory RAM sizes, TPP1), and the panel says when the effective controller differs from the header.
• Selecting a sprite follows its tile as the game animates it; picking a tile yourself pins it. Links from tiles and the memory map open the Memory panel. Clicking around while paused keeps the last activity numbers.
• The picture line says how long before the current CPU state it was drawn.

Clearer lessons

• Stepping, running, pressing game keys, or changing capture during the guided lesson now leaves it cleanly, so old explanations never describe a different state. Starting again resets to a known frame and checks each expected event before moving on.
• Lesson pages add short prediction and explanation prompts and spell out instructions in plain language ("copy A = 73 into player_x").

Download

Platform	File	How to run
Windows 10/11 (64-bit)	console-observatory-0.5.0-windows-x64.zip	Unzip anywhere and run console-observatory.exe; nothing else to install. The app isn't code-signed, so Windows SmartScreen may ask first: choose More info → Run anyway.
Ubuntu 24.04 (x86-64)	console-observatory_0.5.0_amd64.deb	sudo apt install ./console-observatory_0.5.0_amd64.deb, then start Console Observatory from the app menu.

SHA256SUMS.txt lists each file's checksum. The app runs offline; it needs no browser, server, or account. No commercial game is included; open your own .gb/.gbc files.

Good to know

• It emulates the original monochrome Game Boy (via the SameBoy core); no Game Boy Color mode, Super Game Boy extras, or sound output yet.
• OAM DMA is observed (the request, then a later check of sprite memory), not traced byte by byte.
• Tested on Linux and on Windows in CI; not yet on a physical Windows PC.

How these files were made

The Release workflow built both files from this release's commit after the same checks as CI passed on that machine: five test suites, the widget suite on the native platform, and on Windows a launch of the unzipped package with only System32 on PATH. CI also runs the engine suite under AddressSanitizer. Details: docs/VERIFICATION.md.

Console Observatory 0.4.0: OAM DMA made visible, and tooltips that explain everything

Console Observatory is a native desktop Game Boy teaching lab. Run a game, pause it at any moment, and follow what happens in the CPU, memory, and graphics hardware, with every panel showing the same instant.

What's new

Sprite memory written by DMA now has an answer

Most commercial games build their sprite table in work RAM and have the hardware copy it into sprite memory (OAM) once per frame, by writing a page number to $FF46. Until now, those sprite bytes showed no writer. Now:

• Select a sprite byte and the writer panel says OAM DMA, which instruction requested it, and how many of the 160 bytes matched their source. The source address is a link; click it to see the instruction that put the value there.
• Run until written (F9) on a sprite byte stops right after the copy.
• The Sprites panel says where OAM's contents came from, the system overview shows the copy as a work RAM → OAM arrow with a count, and the $FF46 write is labelled "starts OAM DMA".

Tooltips that explain everything

Hover almost anything for a short, plain-language explanation written for curious newcomers: registers and flags, every memory byte (its region and, for hardware registers, what the register does), each part and arrow of the system overview, cartridge banks, tiles down to a single bit or pixel, panel tabs and title bars, buttons and menus.

Download

Platform	File	How to run
Windows 10/11 (64-bit)	console-observatory-0.4.0-windows-x64.zip	Unzip anywhere and run console-observatory.exe; nothing else to install. The app isn't code-signed, so Windows SmartScreen may ask first: choose More info → Run anyway.
Ubuntu 24.04 (x86-64)	console-observatory_0.4.0_amd64.deb	sudo apt install ./console-observatory_0.4.0_amd64.deb, then start Console Observatory from the app menu.

SHA256SUMS.txt lists each file's checksum. The app runs offline; it needs no browser, server, or account.

No commercial game is included. The app comes with two small original examples (File › Bundled examples); open your own .gb/.gbc files with File › Open or by dropping one on the window.

Good to know

• It emulates the original monochrome Game Boy (via the SameBoy core). Game Boy Color-only games show their own "needs Color" screen, Super Game Boy extras are absent, and there is no sound output yet.
• DMA is observed rather than traced byte by byte: the app records the request and checks OAM against the source once the copy must have finished. It needs Capture writes (on by default).
• Tested on Linux and on Windows in CI and under Wine; not yet on a physical Windows PC. Please report anything odd.

How these files were made

The Release workflow built both files from this release's commit, after the same checks as CI passed on that machine: five test suites (emulation parity with tracing on and off, inspection purity, stepping, the lessons, cartridge banks, OAM DMA timing, tooltips, ROM reproducibility, vendored-source integrity), the widget suite on the native platform, and on Windows a launch of the unzipped package with only System32 on PATH. Details: docs/VERIFICATION.md.

Console Observatory 0.3.0: open any Game Boy ROM, with cartridge banks made visible

Superseded by 0.4.0, which adds DMA-aware sprite writers and explanatory tooltips. Download the latest release unless you need this one.

Console Observatory is a native desktop Game Boy teaching lab. Run a game, pause it at any moment, and follow what happens in the CPU, memory, and graphics hardware.

What's new

• Open any Game Boy ROM up to 8 MiB (File › Open, Ctrl+O, or drop a file on the window), with every cartridge controller SameBoy emulates (MBC1, MBC2, MBC3 with clock, MBC5, MBC7, MMM01, HuC1, HuC3, camera, TPP1). The 32 KiB limit of earlier versions is gone.
• Cartridge · banks panel: the CPU's three cartridge windows linked to every ROM and RAM bank, lines showing what is mapped right now, banks shaded by how much code ran from them, a plain explanation that adapts to the cartridge, and every bank switch with its effect ($2000 ← $02 · ROM bank 1 → 2). Run until the bank changes stops right after the next switch.
• Bank-switching demo (File › Bundled examples) with a short lesson that presses A and stops at the real switch.
• Battery saves: a .sav file next to the ROM, loaded on open and saved automatically.
• The built-in startup program now leaves the machine in the state real games expect.

Download

Platform	File	How to run
Windows 10/11 (64-bit)	console-observatory-0.3.0-windows-x64.zip	Unzip and run console-observatory.exe. Not code-signed: SmartScreen may ask, choose More info → Run anyway.
Ubuntu 24.04 (x86-64)	console-observatory_0.3.0_amd64.deb	sudo apt install ./console-observatory_0.3.0_amd64.deb

SHA256SUMS.txt lists each file's checksum. No commercial game is included.

Good to know

• Original monochrome Game Boy only; no sound output.
• In this version, sprite bytes written by DMA (most commercial games) show no writer; 0.4.0 adds that.

Built and verified by the Release workflow from this release's commit (same checks as CI). Details: docs/VERIFICATION.md.

Console Observatory 0.2.0: Windows build, a guided lesson, and visual inspectors

Superseded by 0.4.0. This version only runs the bundled teaching game and other 32 KiB ROM-only cartridges; 0.3.0 and later open any Game Boy ROM.

Console Observatory is a native desktop Game Boy teaching lab: run a tiny original game, press Right, and follow the change from the joypad through a CPU instruction to memory, sprite memory, the next frame, and the tile bits that make the picture.

What's new

• Windows build: a portable ZIP that runs on Windows 10/11 without installing anything.
• Guided lesson "Follow one press of Right": five steps, each ended by a real emulator event, with the system overview highlighting the path.
• Run until written (F9) for any memory byte.
• Sprites and tiles inspector: the sprite table and VRAM tiles decoded bit by bit.
• Memory map of all 64 KiB, coloured by writes and code execution.
• System overview with live values; dockable panels.

Download

Platform	File	How to run
Windows 10/11 (64-bit)	console-observatory-0.2.0-windows-x64.zip	Unzip and run console-observatory.exe. Not code-signed: SmartScreen may ask, choose More info → Run anyway.
Ubuntu 24.04 (x86-64)	console-observatory_0.2.0_amd64.deb	sudo apt install ./console-observatory_0.2.0_amd64.deb

SHA256SUMS.txt lists each file's checksum.

Built and verified by the Release workflow from this release's commit (same checks as CI). Details: docs/VERIFICATION.md.