What Is jsbeeb and What Can You Do With It?

jsbeeb (bbc.xania.org) is a browser-based emulator for the BBC Micro, the popular 1980s British home computer. You open the page and a working BBC B starts in your browser — no installer, no plugin, no account. It's aimed at anyone who wants to run BBC Micro software, revisit the machine, or poke at 6502 code without owning the hardware. It works best in Chrome or Firefox, according to the site.

What the emulator gives you

The core of the page is a running BBC Micro with a set of controls around it:

• Media loading — drag and drop a disc, tape, or save state onto the emulator, or use the media panel to insert images into Drive 0/1 or the cassette.
• Reset options — soft reset and hard reset, plus a "BBC B Media Reset" control.
• State handling — save state, load state, and rewind, so you can step back from a mistake.
• Display — fullscreen mode and a Help panel.
• Disc surface view — a visualisation of the disc surface, with Drive 0/1 and Side 0/1 selectors, pulse display, and format options for drive 0/2 and drive 1/3.
• Cassette controls — a data recorder with rewind, play, stop, and eject, plus a counter and a "Show power" toggle.
• Debugger — a 6845 state and register view, memory address display, and a 6502 register/instruction panel (A, X, Y, S, PC, flags) with step, step over, step out, breakpoint, and memory navigation keys.

The default disc loaded is Elite, made available by Ian Bell. The About panel credits Matt Godbolt as the author, notes the emulator is based on Sarah Walker's b-em, and mentions Andrew Hague's Acorn Atom emulation and the Visual 6502 project for cycle-accurate work.

Things worth knowing before you start

Audio may be suspended. The page shows a notice that your browser has suspended audio until you click or press a key — so if a game seems silent, interact with the page first.

Saving to Google Drive. There's a "Connect Google Drive" option for storing discs, with a choice of where to save (in this browser or on Google Drive). The privacy note says logging in to Google Drive stores only what's needed to reach your own discs, and that this is never shared with the jsbeeb developers.

Privacy and hosting. The site states it uses cookies for simple analytics, keeps no server logs, and stores nothing on jsbeeb servers — it's a static page served from an AWS bucket. Use is at your own risk, for any lawful purpose.

Self-hosting. If you'd rather run your own copy, the source is on GitHub.

Who it's for

• Nostalgia and retro computing — run BBC Micro titles like Elite directly in a tab.
• Learning 6502 assembly — the built-in debugger lets you step through code, set breakpoints, and inspect registers and memory.
• Disc and tape experimentation — the disc surface and cassette panels are useful if you want to see how media images behave.
• Quick access without hardware — no emulator install, no ROM files to hunt down for the default setup.

If you want a zero-setup way to use a BBC Micro in the browser, open bbc.xania.org and click the page to enable sound. If you need a specific machine model beyond what's emulated, or you want to modify the emulator itself, the GitHub source is the place to look.