rec.autos.simulators

When you load n2 does it log out "pentium class machine"?
My machine hangs when this is logged out.
This happens when I run the cyrix optimizer programs (m1opt, 6x86opt, or
cpuiden.exe)
If i don't run these, n2 loads fine, but it doesn't display "pent.. cl..
mach..".
My feeling is that when n2 detects pentium it loads a different
instruction
set.  486 vs. pentium.
Running on asus ip55t2p4 rev 3.1 with 512 cache on board.
Any suggestions?

Brian Johnson

I have the same problem I happen to have the same motherboard and cpu
that you have.
The 686_p.exe program that i have seen on a lot of web pages does not
solve the problem.
They have apparently included some pentium instructions in the game
that are not compatible with the cyrix 6x86.
My question is since the program treats the 6x86 like a 486 how much
is it costing me in performance?

The program treats your chip as a 486, because that's what it
basically is, a very, very fast 486.

I don't think it's costing you much performance at all. With DMA based
video cards (and to a lesser extent DMA for sound), you'll see your
joystick reads be a little less exact (because the Cyrix doesn't
support the Pentium RDTSC instruction). Other than that, there are no
Pentium-specific features that are switched based on CPU_ID. (that I'm
aware of.)

---Jim Sokoloff

The 'optimizer program' works fine for me (not sure if I get a
performance increase) unless I use the CPUIDEN program. I'm running a
Cyrix 166+. Nascar2 is the only program I have ran across that has a
problem with the 'Pentium ID'. It will not run if I use the CPUIDEN
program.

In answer to the question about the program(s)...There are
'optimization' programs that are supposed to get more performance out of
the Cyrix/IBM cpu's. These can be ran in your autoexec.bat or as needed.
Atleast one of the programs has a switch that can be entered that will
cause Win95 to ID the chip as a Pentium. CPUIDEN.exe is a program that
will cause Win95 to report Pentium.

For more info or to DL one of these check here:
http://www.ionet.net/~rbdavis/

I'm not sure why Nascr2 would crash unless the Pentium version has
optimized code for a Pentium. My best guess is that it does (Maybe Jim
can enlighten us?) but I don't know what (if anything) that we loose
with the Cyrix.

Good Luck,
Alan

A Cyrix chip is *NOT* a Pentium. If you install a program that causes
the Cyrix chip to incorrectly report itself as a Pentium, you deserve
for your programs to crash IMO.

With a non-Pentium, you get a less accurate joystick routine (because
of the lack of RDTSC on non-Pentiums). In any event, you are getting
the full performance of your CPU.

---Jim Sokoloff

As of this *instant* in time, I don't think it will be.

If it is possible to fix, we will. We're trying a few things, but the
lack of some Pentium instructions is obviously hampering... Obviously
though, if we come up with a solution that works, we'll make it
available.

---Jim Sokoloff

<SNIP>

I do use an optimization program (without the 'Pentium ID') because it
does seem to make a slight difference (perception and benchmarks).

BUT, in your reply, you mentioned a different Joystick read routine for
the Cyrix...Is that possibly in some way the source of the problem with
N2 and Cyrix when running the Renddma version. I've yet to come across
anyone who is able to run N2 Renddma with a Cyrix 6x86 that doesn't
experience major probs with steering (T2). Nasrend doesn't have the
problem with the steering. Renddma 'jerks' hard left.

Is the Renddma/Cyrix problem something that can be 'fixed' (game card,
tsr, patch, etc.) or is it something that probably can't be addressed
due to the complexity of the program (and then the best answer is 'get a
Pentium' ;o) ).

...of course then there's those AMD K series cpus... ;o)

Thanks,
Alan

[huge snip]

I have a long, fairly technical description of why exactly the Cyrix
(and AMD presumably) chips don't do well w.r.t joystick reads while
using DMA extensively in this database a while back.
(www.dejanews.com, search for Cyrix DMA RDTSC or something like that)
We have confirmed with Cyrix that their chips prior to the
(unreleasesd) M2 do not suppor the Pentium RDTSC instruction. We have
been investigating alternative solutions for more accurate joystick
routines for non-Pentium machines, but so far, we haven't found a
solution that works for 100% of the cases. To be perfectly frank, this
is not the highest priority problem facing Papyrus right now, as Cyrix
and AMD combined make up less than 10% of the market. There are other
problems which are receiving more attention, but this problem is not
being ignored...

---Jim Sokoloff

I have a cyrix 166+ and N2, Indy2, and F-1 all run fine. I upgraded to this
from a Intel P133 there was an improvement in fps in all three of the
games, as far as a problem with the joystick I never noticed it when I
switched to the cyrix cpu all though I use a home made wheel and pedals. I
did notice that n2 didn't recognize my cyrix as a pemtium, but who cares
the bottom line is the cyrix works just fine and is faster for less money.
        One thing though I don't use a rendition video card. ( there is more to
life then N2 and Indy2 ) and in my humble opinion that is the only thing I
find the rendition cards good for.
                                Denny M.

That's because the joystick problems occur with the 3D accelerated DMA
version.

--

Mike Radler

Member Hawaii Ace League http://www.dithots.org/hal

To clarify things a bit...

It is ONLY when using the combination of a Cyrix 6x86, Rendition vid
card, and then running Nascar2's Renddma.bat that there is a controller
problem (and I assume that is true for all using that combo). Nasrend,
which is the 'regular' Rendition version, runs fine (even with Cyrix).
The Renddma.bat version will have the fastest fps but can only be ran on
systems that support DMA bus mastering (Depending on MB, Even some Intel
systems can't run it).

If you are using a Cyrix with ANY OTHER Vid card odds are great you WILL
run as fine as your system will allow and you will not notice a control
problem. You, of course, can't run EITHER Rendition version on a non
Rendition video card.   http://www.rendition.com

As I understand Jim Sokoloff's reply, the Cyrix problem stems from a
difference in the Pentium and Cyrix instruction set and how the program
uses them.

In summary:
The Cyrix-Rendition-N2 control is fine for me in regular Rendition mode.
The graphics ARE improved over the regular N2 graphics (non Rendition).

If you are considering a Cyrix 6x86-Rendition combo be aware that you'll
most likely NOT be able to use the fastest mode (Renddma) but that
you'll be fine with the regular Rendition mode (Nasrend). You should see
better graphics and fps with 'Nasrend'. Unfortunately, you won't be able
to use the 'fastest fps''Renddma' version unless a Cyrix 'patch' comes
down the pike...;o)

...hope that clears things up a bit...

Alan