Dr Andy Wright ran BetaSoft, a one-man software house through which he sold BetaBASIC: an improved version of BASIC for the Sinclair ZX Spectrum. When MGT were designing the Sam, they approached Doctor Wright and contracted him to provide the ROM and DOS.
The Sam ROM includes a full BASIC interpreter, floating-point maths library, and command-line user interface. The DOS, which is bootstrapped from disk to memory via a small ROM routine, supports file operations onto one or two floppy disk drives. Later on, Dr Wright wrote MasterBasic and MasterDos; extended versions of his earlier work, which he sold through BetaSoft.
He also wrote Games Master, an original sprite-based games creation system. Because of its flexibility, and that it was very easy to learn, Games Master games became very common as contributions to disk magazines such as Fred, and even the occasional commercial title such as T 'n' T.
File Manager by Carol Brooksbank was also released through BetaSoft.