Disks that work on real hardware

The ZX Spectrum +3 was the only Spectrum with a built-in floppy drive, using its own +3DOS disk format — and that format has real, specific rules that a disk image has to follow exactly to be usable. plus3 builds to those rules.

What it does

• Create blank +3DOS disk images with the standard +3 layout, ready to use.
• Add, list, extract, and delete files on a disk image directly from the command line, including detokenising a BASIC program straight to readable text on extraction.
• Convert between tape and disk — bring a program in from a TAP file, or pull a file back out as a tape.
• Build a standalone +3DOS file — a correctly headered program or code file — without needing to create a whole disk image first, for cases where that's all you actually need.

plus3 is also available as a Go library, for anyone building their own tools that need to read or write +3DOS images directly.

Why it matters

The +3DOS format has real, specific requirements — where the directory sits on the disk, exactly how a file header is laid out, what makes a header valid — and getting any of it slightly wrong produces a disk image that looks fine but that real +3 hardware, or other +3DOS-aware software, refuses to recognise. plus3's disk images are built to the specification directly, verified against real +3-written disks, so what you create actually works — not just in this emulator, but on the real thing.