pointer question

[Hans Albertsson]

[come & get it ]

	I know one machine where pointers are not just different
	length, but different data structures as well. I'm thinking
	of the DEC PDP-10, a 36-bit machine, ( VERY nice.. ) where
	most stuff gets put in an integral no. of full words, and a
	pointer	to one of these objects is 18 bits, that is a Half-word.
	
	However, characters can have one of many representations,
	usually, but not always, 7 bits each ( other usual sizes are
	5 or 6 bits ), and packed an integral no. of characters in a
	word, usually 5 7-bit char:s ( = 35 bits ) in a word. The left-
	over bit is ignored... This means that a "pointer" to a
	character string is a complex structure, containing A) the
	starting address, B) the "Byte Size" in bits plus the "Byte
	Number" you're presently looking at. It takes up MOST of a
	36-bit word.
	
	Other examples probably exist.