The SNES relies heavily on mapping - for example, without mapping it wouldn't be possible to give all banks of $00 – $3F two pages of WRAM directly at the beginning of the bank. Range does not end with $FF - this is because $FF is the last address of a page, and after this byte a new page begins. You will notice that in the tables below there is no entry in which a certain memory A page is the smallest mappable unit of a Pages are also used for normal PCs (x86/x86-64 architectures) and are hence not exclusive for the SNES. If that's how the machine is supposed to work). Pages are used whenever the machine has to perform mapping tasks (for example, ensuring that address $AABBCC and address $DDBBCC point to the exactly same data, Therefore the SNES has $100 or 256 Banks (start at $00, end at $FF). With three bytes of address space the SNES can address up to 16 Megabytes (2^24 or 1<<24 or 16777216 Bytes = 16384 Kilobytes = 16 Megabytes).īeware that just because the SNES can address 16 Megabytes does not mean it also HAS 16 MB of RAM (here so-called WRAM) - it will be explained in detail later. The bank of the address $AABBCC is $AA (170). Addresses are often shown as hexadecimal values.īank: 64 Kilobytes (65536 or $10000 bytes), basically the most significant byte of the 3 byte address the CPU understands. $ or 0x prefix: the following number is hexadecimal. Before explaining LoROM and HiROM though, we should define some keywords here: There are two main types of SNES cartridges, the SNES community refers to them as LoROM and HiROM cartridges.
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