What does the ROM "shawde" is mean?

This bit I know. Executing code from a 150ns (or slower), 8-bit ISA bus ROM is very slow compared to executing from RAM. To speed up execution of the BIOS code, it can be copied to RAM. Using memory management, this area of RAM can be mapped into the address space that was originally used by the ROM, so the code appears in the same place but runs faster. This used to be particularly useful for VGA BIOSes back in the days of DOS.hbxffrm wrote:What does the ROM "shawde" is mean?