RL02 version of UNIX6?

[Paul Koning]

> On Feb 1, 2017, at 5:55 PM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
> 
>> From: William Degnan
> 
>> I do not have an EIS installed. I have one however, I can try it. I am
>> unsure if it's good or not, but I guess I am going to find out.
> 
> Oh yeah, without that, you're totally hosed, Unix-wise. The V6 C compiler
> puts out MUL etc all over the place (e.g. for structure pointer math), so
> there's absolutely no way to run vanilla V6 Unix without it.
> 
> (The GCC compiler claims to be able to compile C to machines without the
> EIS; it might be an interesting hack to see if that could be used to get
> V6 running on a machine without the EIS. The machine language startups
> would still need work, though. And the bootstrap. :-)

Yes, GCC should do that correctly.  If not, report the bug and I'll take a look at it.  Dealing with the output might be a nuisance; it generates GNU "as" compatible text, or something that pretends to be DEC format but isn't actually.  You may need some post-processing to cast the output into the syntax that V6 "as" expects.

If you use gcc, you will also need whatever libgcc modules it happens to call on in the generated code; minimally the mul/div routines if you ask for no-eis of course.

	paul