On Mon, Dec 31, 2018, 1:38 PM Noel Chiappa <jnc@mercury.lcs.mit.edu wrote:

>     > From: Paul Winalski
>
>     > What is magic number 0411?  That one I've never heard of before.
>
> It's a PDP-11-ism. Separate I+D.
>

Venix/86, a v7 sys iii hybrid that ran on 8086/286 also uses it for
basically the same thing... its compiler was limited to one 64k code
segment and one 64k data / stack segment. The syscall interface depends on
this quirk as well...

Warner

>