Don McKenzie wrote:

> Both the Parallel and serial ports on a Portfolio aren't at the usual
> addresses as seen on an XT, even though it supposed to be DOS 2 point
> something compatible.

  Ahh, well, there's a few machines that were "DOS 2.x compatible".
Doesn't mean to suggest they were "PC Compatible" or "IBM Compatible"
though.  Certain succulent fruit come to mind.  I nearly got my hands on
one, but the owner thought I wasn't interested because I hadn't picked
it up, and stuck it out in her (or their) garage sale.  Apparently
someone paid $10 for it before I twigged and got there!

  Another one was seen at a garage sale asking something absolutely
ridiculous (about $50 as I vaguely recall!).  Talk about p* in the wind!
Neither had more than the disk sitting in the drive and maybe a tatty
manual or two!

  Why do I care?  Well, I sort of ... collect them ... sort of. (Blush!)

> Sure it could be done with a bit of effort. The parallel port uses an
> 8255, so special drivers are required here.

  Isn't that what Nigel, David or Ken published some source code for?

  Cheers,
        Paul B.