[[File:ZX Spectrum Plus3.jpeg|thumb|ZX Spectrum +3]]
The '''ZX Spectrum +3''' looked similar to the +2 but featured a built-in 3-inch [[floppy disk]] drive (like the Amstrad CPC 6128) instead of the tape drive, and was in a black case. It was launched in 1987, initially retailed for £249 and then later £199 . The ZX Spectrum +3 included CP/M support in ROM and was the only Spectrum capable of running the [[CP/M]] operating system without additional hardware, allowing access to its vast library of available software.
The +3 saw the addition of two more 16 kB ROMs. One was home to the second part of the reorganised 128 ROM and the other hosted the +3's disk operating system. This was a modified version of Amstrad's [[PCWDOS]] (the disk access code used in [[LocoScript]]), called +3DOS. These two new 16 kB ROMs and the original two 16 kB ROMs were now physically implemented together as two 32 kB chips. To be able to run CP/M, which requires RAM at the bottom of the address space, the bank-switching was further improved, allowing the ROM to be paged out for another 16 kB of RAM.