To allocate a file on a specific area on a disk or drum, the command:
@ALLOCATE-FILE <file name> <page address> <number of pages>
will create a continuous file, starting from the <page address> given. The page size is always 1K words (2K bytes) and the page address is given as a page number from the start of the device, which is always page 0.
If more than one version is created, they are allocated after each other with version 1 from the specified page address.