Infinity symbol in bookbinding to indicate that a book is printed on acid-free paper and will therefore be long-lasting. In modern mysticism, the infinity symbol has become identified with a variation of the ouroboros, an ancient image of a snake eating its own tail that has also come to symbolize the infinite, and the ouroboros is sometimes drawn in figure-eight form to reflect this identification, rather than in its more traditional circular form. In the works of Vladimir Nabokov, including "The Gift" and "Pale Fire", the figure-eight shape is used symbolically to refer to the Möbius strip and the infinite, for instance
Sideways address space Sideways address space The "Sideways" address space on the Acorn BBC Microcomputer, Electron and Master-series microcomputer was Acorn's bank switching implementation, providing for permanent system expansion in the days before hard disk drives or even floppy disk drives were commonplace. Filing systems, application and utility software, and drivers were made available as Sideways ROMs, and extra RAM could be fitted via the Sideways address space. The Advanced User Guide to the BBC Micro only refers to the Sideways address space as "Paged ROMs" because it predated the use of this address space for RAM expansion. The BBC B+, B+ 128