Lexicon

B

• Bank (mapper): A chunk of memory (8 or 16 KB) managed by a register that allow to select what part of the mapped ROM (segment) is visible in the given bank. For 8 KB mappers, there is 2 banks per page and for 16 KB one, there is 1 bank per page1.

M

• Mapper: A device that contains one or more registers that allow to select the memory accessible through the pages where the device is selected. These registers are generally accessible either via I/O ports, or via write access to given addresses.
• Mapped-RAM: A device with a mapper that allow to select chunk of the RAM (called 'segment') to be visible in each mapper's address blocs (called 'bank').
• Mapped-ROM: A device with a mapper that allow to select chunk of the ROM (called 'segment') to be visible in each mapper's address blocs (called 'bank').
• MegaROM: A ROM of 128 KB or more (1048576 bits, or 1 mega-bit, hence the name MegaROM). All MegaROM are Mapped-ROM.
• Memory space: The total memory address space visible by the Z80 (64 KB from 0x0000 to 0xFFFF).

P

• Page (memory): A quarter of the memory space (16 KB). The page number is defined by the 2 higher bits of the address. MSX allow to select an given slot/subslot to be visible in each page.

S

• Segment (mapper): A chunk of mapped ROM (8 or 16 KB) that can be selected into a given bank.