From: utzoo!decvax!microsof!uw-beave!jim
Newsgroups: net.unix-wizards
Title: Re: Information on Unix/Vax peculiarities
Article-I.D.: uw-beave.246
Posted: Fri Dec 10 09:37:47 1982
Received: Sat Dec 11 06:56:06 1982
References: sri-unix.4758

I haven't seen this posted here yet, although I'm surprised no one has
mentioned it.

On the Intel 8086 (as in IBM PC) an int is 16 bits, and pointers are 32
bits.  The 32 bits is broken down into a 16 bit offset and a 16 bit segment,
and the total address space is only 20 bits, but you need to use two
registers to store a pointer.  The main problem is that offsets wrap around,
so incrementing a pointer (using the hardware instructions to do so) does
not always give you the address of the next memory location.

In practice I haven't had much trouble with this in porting C code to the
8086 (although there are lots of other things that do cause trouble).