The computer is somewhat compatible with the Spectrum, in that it has an extended version of Sinclair BASIC written by Dr. Andrew Wright, the author of Beta BASIC, and it can load a fair proportion of Spectrum games.
The machine was sometimes regarded as a clone of the Spectrum or dubbed a 'SuperSpectrum', but many users would insist that it was more than that.
It was not compatible with software for the 128K/+2/+3 Spectrums, as it used an entirely different memory paging scheme.
It came equipped with either 256 KiB or 512 KiB of RAM, although external 1 MiB RAM packs were available, of which up to four could be connected. External memory required software to be specially written to make use of it, and as such, the main use of external memory is for RAM disks when using Dr. Wright's Master DOS.
Up to two floppy disk drives can be attached, although the system can load from tape. Due to the large amount of memory required for use of the Coupé's high-colour graphics mode, software for the machine is often distributed on floppy disks (or floppy disk images), as although tape loading is slightly faster than on the Spectrum, this does not make up for the increased amount of data that must be loaded.
Each SAM Drive has a VL1779 (WD1779) floppy controller attached, meaning that it is possible to access both drives simultaneously. Drives slot into bays in the front of the machine, towards the left and right sides.
Disk access requires a DOS, and SAMDOS was provided with the SAM Drive. The original SAM ROM contains a bug in its bootstrapping code, preventing DOS from being loaded from disk. This was fixed in later versions.
SAMCo produced the Messenger which allows transfer of programs (snapshots) between the SAM Coupé and ZX Spectrum.
A reimplementation of parts of the Spectrum ROM sufficient for playing of many Spectrum games was made available, known as the 'Skeleton' ROM.
Upon the request of Hans De Goede on behalf of the Fedora Linux distribution, Dr Andrew Wright granted permission for all of his titles for the SAM Coupé (including the SAM Coupé ROM) to be freely redistributed. Since then, Dr Wright granted permission for the SAM ROM to be redistributed under the GNU General Public License, and has granted similar permission for Skeleton ROM to be redistributed under the GPL since then.
The letters SAM are said to have stood for Some Amazing Micro during development, according to Alan Miles in an interview for ZAT (a paper-based magazine for the Spectrum and SAM, pronounced Zed Ey Tee), but the initials were kept with the expansion of those initials dropped prior to release. The phrase Coupé is said in the same interview to relate to the distinctive appearance of the machine, and an 'ice cream coupé' that was served at a restaurant.