Memory Map - Revision history

Nitro2k01 at 02:11, 5 April 2020

2020-04-05T02:11:38Z

PinoBatch: $0000-$3FFF is only usually fixed. MBC1M and Wisdom Tree regularly switch it.

2019-07-08T20:47:40Z

$0000-$3FFF is only usually fixed. MBC1M and Wisdom Tree regularly switch it.

ISSOtm: /* General Memory Map */ Oops, fixed the table

2017-05-09T16:21:01Z

‎General Memory Map: Oops, fixed the table

ISSOtm: Added info...

2017-05-09T16:20:25Z

Added info...

Mantidactyle: /* External Memory and Hardware */

2015-05-04T19:21:15Z

‎External Memory and Hardware

FireFly: Fix wikilink and remove stray ']'

2015-01-05T09:29:33Z

Fix wikilink and remove stray ']'

Furrtek at 17:08, 8 January 2012

2012-01-08T17:08:39Z

TechFalcon: Created page with 'The gameboy is having a 16bit address bus, that is used to address ROM, RAM, and I/O registers. == General Memory Map == 0000-3FFF 16KB ROM Bank 00 (in cartridge, fixed …'

2010-10-08T01:49:40Z

Created page with 'The gameboy is having a 16bit address bus, that is used to address ROM, RAM, and I/O registers. == General Memory Map == 0000-3FFF 16KB ROM Bank 00 (in cartridge, fixed …'

New page

The gameboy is having a 16bit address bus, that is used to address ROM, RAM, and I/O registers.

== General Memory Map ==
0000-3FFF 16KB ROM Bank 00 (in cartridge, fixed at bank 00)
4000-7FFF 16KB ROM Bank 01..NN (in cartridge, switchable bank number)
8000-9FFF 8KB Video RAM (VRAM) (switchable bank 0-1 in CGB Mode)
A000-BFFF 8KB External RAM (in cartridge, switchable bank, if any)
C000-CFFF 4KB Work RAM Bank 0 (WRAM)
D000-DFFF 4KB Work RAM Bank 1 (WRAM) (switchable bank 1-7 in CGB Mode)
E000-FDFF Same as C000-DDFF (ECHO) (typically not used)
FE00-FE9F Sprite Attribute Table (OAM)
FEA0-FEFF Not Usable
FF00-FF7F I/O Ports
FF80-FFFE High RAM (HRAM)
FFFF Interrupt Enable Register

== Jump Vectors in First ROM Bank ==
The following addresses are supposed to be used as jump vectors:
0000,0008,0010,0018,0020,0028,0030,0038 for RST commands
0040,0048,0050,0058,0060 for Interrupts
However, the memory may be used for any other purpose in case that your program doesn't use any (or only some) RST commands or Interrupts. RST commands are 1-byte opcodes that work similiar to CALL opcodes, except that the destination address is fixed.

== Cartridge Header in First ROM Bank ==
The memory at 0100-014F contains the [[The Cartridge Header|cartridge header]]. This area contains information about the program, its entry point, checksums, information about the used MBC chip, the ROM and RAM sizes, etc. Most of the bytes in this area are required to be specified correctly. For more information read the chapter about The Cartridge Header.

== External Memory and Hardware ==
The areas from 0000-7FFF and A000-BFFF may be used to connect external hardware. The first area is typically used to address ROM (read only, of course), cartridges with [[Memory Bank Controllers|Memory Bank Controllers (MBCs)]] are additionally using this area to output data (write only) to the MBC chip. The second area is often used to address external RAM, or to address other external hardware (Real Time Clock, etc). External memory is often battery buffered, and may hold saved game positions and high score tables (etc.) even when the gameboy is turned of, or when the cartridge is removed. For specific information read the chapter about Memory Bank Controllers.

← Older revision		Revision as of 02:11, 5 April 2020
Line 1:		Line 1:
		+	{{Pandocs\|memory-map}}
		+
	The gameboy has a 16bit address bus, that is used to address [[ROM]], [[RAM]], and [[I/O registers]].		The gameboy has a 16bit address bus, that is used to address [[ROM]], [[RAM]], and [[I/O registers]].

@@ Line 11: / Line 11: @@
 |3FFF
 |16KB ROM bank 00
-|From cartridge, fixed bank
+|From cartridge, usually a fixed bank
 |-
 |4000

@@ Line 22: / Line 22: @@
 |8KB Video RAM (VRAM)
 |Only bank 0 in Non-CGB mode
-|Switchable bank 0/1 in CGB mode
+Switchable bank 0/1 in CGB mode
 |-
 |A000
@@ Line 38: / Line 38: @@
 |4KB Work RAM (WRAM) bank 1~N
 |Only bank 1 in Non-CGB mode
-|Switchable bank 1~7 in CGB mode
+Switchable bank 1~7 in CGB mode
 |-
 |E000

@@ Line 16: / Line 16: @@
 |7FFF
 |16KB ROM Bank 01~NN
-|From cartridge, switchable bank via [[Memory_Bank_Controllers|MBC]]
+|From cartridge, switchable bank via [[Memory_Bank_Controllers|MBC]] (if any)
 |-
 |8000
 |9FFF
 |8KB Video RAM (VRAM)
 |Switchable bank 0/1 in CGB mode
 |-
@@ Line 35: / Line 36: @@
 |D000
 |DFFF
-|4KB Work RAM bank 1~N
+|4KB Work RAM (WRAM) bank 1~N
 |Switchable bank 1~7 in CGB mode
 |-
 |E000
 |FDFF
-|Mirror of C000~DDFF (ECHO)
+|Mirror of C000~DDFF (ECHO RAM)
 |Typically not used
 |-
 |FE00
 |FE9F
-|Sprite attribute table ([[OAM]])
+|Sprite attribute table ([[Video_Display#VRAM_Sprite_Attribute_Table_.28OAM.29|OAM]])
+|
 |-
@@ Line 65: / Line 67: @@
 |FFFF
 |FFFF
-|[[Interrupts]] Enable Register
+|[[Interrupts]] Enable Register (IE)
+|
 |}
@@ Line 73: / Line 75: @@
 *RST commands: 0000,0008,0010,0018,0020,0028,0030,0038
 *Interrupts: 0040,0048,0050,0058,0060
-However, the memory may be used for any other purpose in case that your program doesn't use any (or only some) RST commands or interrupts. RST commands are 1-byte opcodes that work similiar to CALL opcodes, except that the destination address is fixed.
+However, the memory may be used for any other purpose in case that your program doesn't use any (or only some) RST commands or interrupts. RST commands are 1-byte opcodes that work similar to CALL opcodes, except that the destination address is fixed. Since they are only 1 byte large, they are also slightly faster.
 == Cartridge Header in first ROM bank ==
@@ Line 80: / Line 82: @@
 == External Memory and Hardware ==
 The areas from 0000-7FFF and A000-BFFF may be used to connect external hardware. The first area is typically used to address ROM (read only, of course), cartridges with [[Memory Bank Controllers|Memory Bank Controllers (MBCs)]] are additionally using this area to output data (write only) to the MBC chip. The second area is often used to address external RAM, or to address other external hardware ([[RTC|Real Time Clock]], etc). External memory is often battery buffered, and may hold saved game positions and high score tables (etc.) even when the Game Boy is turned off, or when the cartridge is removed. For specific information read the chapter about Memory Bank Controllers.

← Older revision		Revision as of 19:21, 4 May 2015
Line 79:		Line 79:

	== External Memory and Hardware ==		== External Memory and Hardware ==
−	The areas from 0000-7FFF and A000-BFFF may be used to connect external hardware. The first area is typically used to address ROM (read only, of course), cartridges with [[Memory Bank Controllers\|Memory Bank Controllers (MBCs)]] are additionally using this area to output data (write only) to the MBC chip. The second area is often used to address external RAM, or to address other external hardware ([[RTC\|Real Time Clock]], etc). External memory is often battery buffered, and may hold saved game positions and high score tables (etc.) even when the ~~gameboy~~ is turned of, or when the cartridge is removed. For specific information read the chapter about Memory Bank Controllers.	+	The areas from 0000-7FFF and A000-BFFF may be used to connect external hardware. The first area is typically used to address ROM (read only, of course), cartridges with [[Memory Bank Controllers\|Memory Bank Controllers (MBCs)]] are additionally using this area to output data (write only) to the MBC chip. The second area is often used to address external RAM, or to address other external hardware ([[RTC\|Real Time Clock]], etc). External memory is often battery buffered, and may hold saved game positions and high score tables (etc.) even when the Game Boy is turned off, or when the cartridge is removed. For specific information read the chapter about Memory Bank Controllers.

@@ Line 65: / Line 65: @@
 |FFFF
 |FFFF
-|[Interrupts|Interrupt] Enable Register
+|[[Interrupts]] Enable Register
+|
 |}

@@ Line 1: / Line 1: @@
-The gameboy is having a 16bit address bus, that is used to address ROM, RAM, and I/O registers.
+The gameboy has a 16bit address bus, that is used to address [[ROM]], [[RAM]], and [[I/O registers]].
 == General Memory Map ==
--3FFF   16KB ROM Bank 00     (in cartridge, fixed at bank 00)
+{| cellpadding="2" cellspacing="0" border="1"
--7FFF   16KB ROM Bank 01..NN (in cartridge, switchable bank number)
+|'''Start'''
--9FFF   8KB Video RAM (VRAM) (switchable bank 0-1 in CGB Mode)
+|'''End'''
-  A000-BFFF   8KB External RAM     (in cartridge, switchable bank, if any)
+|'''Description'''
-  C000-CFFF   4KB Work RAM Bank 0 (WRAM)
+|'''Notes'''
-  D000-DFFF   4KB Work RAM Bank 1 (WRAM)  (switchable bank 1-7 in CGB Mode)
+|-
-  E000-FDFF   Same as C000-DDFF (ECHO)    (typically not used)
+|0000
-  FE00-FE9F   Sprite Attribute Table (OAM)
+|3FFF
-  FEA0-FEFF   Not Usable
+|16KB ROM bank 00
-  FF00-FF7F   I/O Ports
+|From cartridge, fixed bank
-  FF80-FFFE   High RAM (HRAM)
+|-
-  FFFF        Interrupt Enable Register
+|4000
-== Jump Vectors in First ROM Bank ==
+== Jump Vectors in first ROM bank ==
 The following addresses are supposed to be used as jump vectors:
-,0008,0010,0018,0020,0028,0030,0038   for RST commands
+*RST commands: 0000,0008,0010,0018,0020,0028,0030,0038
-,0048,0050,0058,0060                  for Interrupts
+*Interrupts: 0040,0048,0050,0058,0060
-However, the memory may be used for any other purpose in case that your program doesn't use any (or only some) RST commands or Interrupts. RST commands are 1-byte opcodes that work similiar to CALL opcodes, except that the destination address is fixed.
+However, the memory may be used for any other purpose in case that your program doesn't use any (or only some) RST commands or interrupts. RST commands are 1-byte opcodes that work similiar to CALL opcodes, except that the destination address is fixed.
-== Cartridge Header in First ROM Bank ==
+== Cartridge Header in first ROM bank ==
 The memory at 0100-014F contains the [[The Cartridge Header|cartridge header]]. This area contains information about the program, its entry point, checksums, information about the used MBC chip, the ROM and RAM sizes, etc. Most of the bytes in this area are required to be specified correctly. For more information read the chapter about The Cartridge Header.
 == External Memory and Hardware ==
-The areas from 0000-7FFF and A000-BFFF may be used to connect external hardware. The first area is typically used to address ROM (read only, of course), cartridges with [[Memory Bank Controllers|Memory Bank Controllers (MBCs)]] are additionally using this area to output data (write only) to the MBC chip. The second area is often used to address external RAM, or to address other external hardware (Real Time Clock, etc). External memory is often battery buffered, and may hold saved game positions and high score tables (etc.) even when the gameboy is turned of, or when the cartridge is removed. For specific information read the chapter about Memory Bank Controllers.
+The areas from 0000-7FFF and A000-BFFF may be used to connect external hardware. The first area is typically used to address ROM (read only, of course), cartridges with [[Memory Bank Controllers|Memory Bank Controllers (MBCs)]] are additionally using this area to output data (write only) to the MBC chip. The second area is often used to address external RAM, or to address other external hardware ([[RTC|Real Time Clock]], etc). External memory is often battery buffered, and may hold saved game positions and high score tables (etc.) even when the gameboy is turned of, or when the cartridge is removed. For specific information read the chapter about Memory Bank Controllers.