Version 2. The minimum version of Flex Navigator is 1.16.

struct FlxPluginHeader {
	char Id[8];
	unsigned short LoadOffset;
	unsigned short EntryOffset;
	unsigned char PluginMode;
	unsigned char Reserved[3];
};

	Header of Plugin for Flex Navigator v1.xx:
		8 bytes Id - identifier of plugin, you should begin from three symbols - FLX
		2 bytes LoadOffset - displacement in page of memory for load (0 - 0x3FFF)
			(according to the 0x3FFF mask, the 2 highest ones are not counted)
		2 bytes EntryOffset - displacement in page of memory for executing (0 - 0x3FFF)
			(according to the 0x3FFF mask, the 2 highest ones are not counted)
		1 byte  PluginMode - modes of work:
			0 - repairing Flex Navigator screen after finish 
			1 - without repairing Flex Navigator screen after finish 
			bit 1 = 0 is the compilation and operation address in addresses 0xC000-0xFFFF
			bit 1 = 1 - compilation and operation address in addresses 0x4000-0x7FFF
		3 bytes Reserved 
	length = 16 bytes

	ATTENTION!!!
	1. Size of plugin code (without header) must be less 4000 bytes.
	2. all plug-ins for Flex Navigator v1.xx must be compiled depending
	   on bit 1 in PluginMode from address 0x4000 or 0xC000 (i.e. org = 0x4000 or org= 0xC000).
	3. When control will return to Flex Navigator, Carry Flag are specify error status:
		CF = 1 an error at the initialization stage (nothing is restored after it)
		CF = 0 no error

History:
14.07.2025: added the ability for plugins to work in window 1 (addresses 0x4000-0x7FFF).