Portable Pointers

[Henry Spencer]

In article <881 at dlhpedg.co.uk> cl at datlog.co.uk (Charles Lambert) writes:
>...pointers to different objects may be different sizes.  Forgetting the
>LONG/SHORT NEAR/FAR perversion of Intel memory models,  does anyone know how
>widespread this kind of implementation is and what are the foremost systems
>involved?

It happens on most machines whose memory is organized by words rather than
bytes.  The exceptions are machines which have "spare bits" in their
normal pointer format.  The Data General machines are this way, in particular.
The Crays are also word-organized, but I think they have spare bits.  There
are undoubtedly other machines, mostly old ones, with word-based memory
architectures.  It's not enormously common, but it happens often enough
to make it hard to ignore.
-- 
The meek can have the Earth;    |    Henry Spencer at U of Toronto Zoology
the rest of us have other plans.|uunet!attcan!utzoo!henry henry at zoo.toronto.edu