On some m68k-based Texas Instruments graphing calculators, high memory addresses that go beyond the physical memory can be used to access the physical memory (the address space folds itself over the physical memory). This range of addresses is called ghost space, because it mirrors the actual physical space.
For TI-89 programmers, ghost space starts from address 0x40000, and it is widely used to circumvent some of the protections introduced with the HW2 (hardware version 2) release of the calculator. This became a compatibility issue with the release of HW3 (the Ti-89 Titanium), where it is disabled, and patching the ROM (HW3Patch) becomes necessary.
Famous quotes containing the words ghost and/or space:
“If an addict who has been completely cured starts smoking again he no longer experiences the discomfort of his first addiction. There exists, therefore, outside alkaloids and habit, a sense for opium, an intangible habit which lives on, despite the recasting of the organism.... The dead drug leaves a ghost behind. At certain hours it haunts the house.”
—Jean Cocteau (1889–1963)
“In the tale proper—where there is no space for development of character or for great profusion and variety of incident—mere construction is, of course, far more imperatively demanded than in the novel.”
—Edgar Allan Poe (1809–1849)