Format of HP 95LX image buffer:
Offset	Size	Description	)
 00h	WORD	number of planes (always 01h on HP 95LX)
 02h	WORD	number of bits/pixel (always 01h on HP 95LX)
 04h	WORD	image width in pixels
 06h	WORD	image height in pixels
 08h  N BYTEs	image data
		requires (WIDTH+7)/8 * HEIGHT bytes