Joy of Joys (porting C-shell)

Boyd Roberts boyd at basser.oz
Fri Jul 8 11:27:00 AEST 1988


Those coders who believe all the world is a VAX are just
wrong-wrong-wrong.  There's a machine in the UK called an
Orion made by some people called High Level Hardware.  It
has TWO (count them) stacks and is word (32 bit) addressed.
Miss-aligned byte references don't fault and the byte offset
is in the HIGH order address bits.  So you get a byte address
space that looks something like this:

	0x00000000
	0x10000000
	0x20000000
	0x30000000
	0x00000001
	0x10000001
	0x20000001
	0x30000001

	    etc...

But then the two stacks come in.  A high order bit (in fact two)
select which stack you're referencing.  Either, the ``scalar''
or the ``vector'' stack.  The address space is NOT contiguous.

Stick to K&R and you're fine.

Somehow High Level Hardware ported 4.2BSD to their box.  They
must have been crazy!!  I used it & it worked.  Hats off to
HLH, but their hardware people should've been shot.  Worse
still I think I heard rumours about them releasing NFS on it.

Now if XDR ain't VAX dependant, I don't know what is.  SysV NFS 2.0
XDR has some real cuties for non VAX byte order machines.  Puke!
One Sunday afternoon & a lot of printf's later I found it.  Assuming
how unions/structures are packed & passed to function calls as their
constituent elements is NO way to write a ``portable'' piece of code.


Boyd Roberts			boyd at basser.cs.su.oz
				boyd at necisa.necisa.oz

``When the going gets wierd, the weird turn pro...''



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