How to Save Files to Disk on Sinclair ZX Spectrum +3

This article explains the specific BASIC command required to save data to the internal floppy disk drive on the Sinclair ZX Spectrum +3 computer. It covers the necessary syntax within the +3DOS environment, distinguishes between disk and tape saving methods, and provides examples of proper usage for programmers and retro computing enthusiasts.

The Sinclair ZX Spectrum +3 was distinct from its predecessors because it featured a built-in 3-inch floppy disk drive. To interact with this hardware, the machine utilized a specific operating system known as +3DOS. While earlier Spectrum models relied primarily on cassette tapes using the standard SAVE "" command, the +3 required users to direct the output specifically to the disk drive unit to ensure data was written to the floppy rather than the tape port.

The primary command used to save files to the disk is SAVE. However, to explicitly target the internal floppy drive, the command syntax typically includes a drive specifier. The internal disk drive is recognized by the system as Drive 3. Therefore, the complete command to save a BASIC program to the disk is SAVE "filename" DRIVE 3. If the default drive has already been set to the disk unit via the DRIVE command, users can simply type SAVE "filename", but including the drive specifier ensures the action is performed correctly regardless of the current default setting.

When saving machine code or other data types, the syntax expands to include the start address and length, such as SAVE "filename" CODE 16384,6912 DRIVE 3. It is important to note that file names on the +3 are limited in length and should adhere to +3DOS naming conventions. Using the correct command structure allows users to reliably store programs and data on floppy disks, taking full advantage of the faster load and save speeds offered by the +3’s integrated disk system compared to traditional cassette tapes.