Memory Information
	RAM Speed On Board RAM Supported sizes in MB Maximum RAM Virtual Memory On Board VRAM Number of VRAM slots	70ns 4MB 4,8,12,20,32 36MB 1Gb 512K* None

Notes

The PowerBook 520, 520c, 540 and 540c have 4Mb soldered on the daughterboard and one DRAM expansion slot. Expandable to 12Mb with 8Mb Apple RAM Expansion Card or up 36Mb with third-party RAM expansion cards. * There is 512K of VRAM available for internal and external video for a total of 1Mb. It is not expandable.

32-BIT Information

This system has 32-bit-clean ROMs allowing it to take advantage of more than 8Mb of physical RAM under System 7 by enabling 32 bit addressing in the Memory Control Panel.