Directory and Disk Searching/Locating a File on Your System
The early implementations of Business BASIC used multiple disk drives. Each disk contained one directory. When a request was made to locate a file (using OPEN, RUN, LOAD, SAVE, ERASE, CALL, or ADDR) the filesystem automatically searched each disk starting with the first. Frequently, the program needed to know which disk the file was ultimately found on. PRO/5 must run in environments that are different from this concept. Some systems have multiple disk drives and multiple directories. Some systems hide the disk drives from the applications that see only multiple directories.
An OPEN command from PRO/5 will cause PRO/5 to search numerous directories until the named file or device is located. The disks searched are specified using the DISABLE/ENABLE and SETDRIVE commands.