Memory Map

Documentation of PotatOS

memory map

address	size	usage	description
0x00000	1024 Byte	unusable	interupt vector table
0x00500	1 Byte	read only	The current color attribute byte is saved here.
0x00501	2 Byte	read only	The return code of the last execution is saved here.
0x00503	2 Byte	read only	This word saves the current length of the path.
0x00505	1024 Byte	read only	The current path is saved here.
0x01000	12288 Byte	unusable	system.sys gets loaded here. It provides all the system calls and should therefor not be overriden.
0x04000	8 KiByte	unusable	directory cache. A copy of the current working directory gets loaded here for quick access. Gets overriden everytime a the directory is changed.
0x06000	8 KiByte	unusable	The file allocation table of the current drive gets loaded here. Is required to allow for file and directories to be read.
0x08000	4 KiByte	read only	strings.sys gets loaded here to allow for language specific error messages etc. Can be accessed by language.asm.
0x09000	700 KiByte	free for use	A user programm gets loaded at address 0x09000. The programm has then guaranteed access to the space from 0x9000 up to 0xB8000 without destroying the kernel.
0xB8000	4096 Byte	special usage	Represents the videobuffer for text mode. Everything written to this area is displayed on the screen. The format is: [ even byte | odd byte ] [ ascii char | color attr. ]
0xB8FA0	???	undefined	Could be available for use. But BIOSes might put CMOS data or mappings here. If A20 Gate is enabled, this could range up to 0xFFFFF. Probe and use at your own risk.