Re: Audacity and Gentoo

On 2006-01-16, Nix <nix-razor-pit@xxxxxxxxxxxxx> wrote:

> Alas, if I put variable-speed fans into amaterasu I fear that the
> machine will blink its fan-failure light

I reckon a pair of wirecutters will fix that... Or some black
insulation tape!

> Bore holes in the door. (Hell, I'm boring holes in the *ceiling* when
> I move amaterasu into the loft, if the noise it makes up there is
> tolerable. I've got to get power and networking and serial console
> leads up there somehow.)

I don't want to bore holes in the rack until I've figured out where I
want the radio receiver to go on a more permanent basis. As for the
utility of a radio receiver for timekeeping, it keeps it all nice and
correct when I've got no net connection (for about 30 mins a year!)
but the main reason it's there is because I like the idea, and I made
it ages ago when I only had ISDN dialup. It cost me about £30 in
parts and is made on a tiny bit of veroboard, not very complicated to
make.

http://www.buzzard.me.uk/jonathan/radioclock.html

As for radio interference, with the amount of stuff in my rack and
around the house, plus the hills around me that mean I can't pick up
telly properly, or freeview, or DAB, and the fact that it's sat on top
of the rack about 3 feet away from any of the foot-thick walls in an
old stone-built house, I suspect it's perfectly capable of sorting out
the wheat from the chaff.. Also the frequency is quite low, something
around the 60KHz range IIRC so it's pretty good at ploughing through
anything.

Current sync state;

*tt89.ripe.net .GPS. 1 u 639 1024 377 30.546 -2.719 3.096
+gw.roaima.co.uk 130.159.196.118 3 u 661 1024 377 51.408 -0.417 1.178
+SHM(0) .rclk. 0 l 18 64 67 0.000 -1.279 1.150

> amaterasu has the OpenPROM bug that leads to it gaining about 15 minutes
> a day, so precise millisecond-accurate syncs seem a little over the
> top. I have to sync every ten minutes just to keep the time synched to
> within a second.)

NTP ought to cope with that, are you running NTP on your home network?

(BTW I'm a bit obsessive with accurate time, with four different
sources of correct time that I can check against each other, two NTP
sources and two non-computer sources)

> Oh, very true. A few really crude back-of-the-envelope calculations
> indicate that you're right: a CPU chip would need to be at about a
> thousand C before it chucked out as much heat as a disk running at 60C.
> I doubt even an Athlon runs that hot. :)

The removal of the heat is a problem, in a small case there's not so
much air room, and heatsinks are large but to cool the disc a good
airflow would be needed. I'll look into it when I get around to it.

> Well, *that* is crackers. Use 1U cases and set up cooling properly.
> This is sort of the *point* of rackmountable cases, isn't it?

To me, it's getting it all into one place with all the wiring safely
out of the way, correct cooling is as important as correct power
wiring of course!

> Nifty! Personally I find MAME very hard to use because the keybindings
> are so baroque. The source is fun to read, though, if only because those
> old machines are often so peculiar. (Plus the 6502 and Z80 and stuff
> like that are blasts from the past for this child of the microcomputer
> age...)

That's the idea behind it, document and preserve the machines in the
form of machine and human readable code. Much more effective than
a simple book about arcade games.

> I'm a bit surprised that *vector* stuff slowed down: it was generally
> the most computationally trivial to implement. I guess the quest
> for total accuracy has costs...

Yes, not sure about that one myself. BTW when I say a game "slows
down", I mean that it starts skipping frames. They almost always run
at the right speed, but the motion gets choppier.

> ... and this is what I use it for (perhaps I'm unusual in treating
> it as a fun read).

Yep, you are plainly bonkers.

I'm going to get mine going tonight and play R-Type for the first time
in months.. Blast off and strike the evil Bydo empire!

> Well, of course. Do it *right*. (Also, a lot of things really depend
> on precise timings, undocumented instructions and so on, so the more
> like the original hardware you can make it, the better. You might
> slow some things down and make some others that never worked right
> suddenly start to function.)

Timing is also the reason behind another often-asked question, "why
doesn't MAME make use of multiple processors", timing gets much harder
to keep track of when you do that. Of course there is a degree of
parallel processing, e.g. MAME on one processor, X on the other.

> How... unexpectedly sane of them (I really never expected that of the
> secrecy-wild Japanese ones).

Yes, odd isn't it ;-) There have been occasions when the
manufacturers have used MAME code in retro products, so I think
there's some give and take going on but it's mostly MAME and us
taking, which makes a nice change.

> Now that really *is* peculiar. Probably also trivially fixable (even if
> distributed as a separate patch). I mean, what would be a better
> emulation of the hardware than the hardware itself?

I think we're talking old 3DFX chips here, MAME don't emulate anything
that's still being seriously sold.

> Oh, that's what all the fibreglass in the loft is for. (Cold water tanks
> catch fire all the time, donchaknow.)

Really? I'll put a smoke alarm up there, about halfway down the
inside of the tank...

> Bah, if you want cool, go ARM.

Price is an issue, ISTR the ARM boards were more expensive than the
x86 clone boards, but there were some very small machines that looked
quite nifty, Gumstix I think, but perhaps a little too small.

> A term I don't know. How do you pipe heat? A solid copper tube?

They're sort-of passive cooling devices, they transfer heat from one
end of the metal flattened tube to the other using thermal convection
of either a liquid or a gas, no moving parts like pumps, just the
convection. Usually you fix one end to the processor and the other to
the case.

> Well, if you want to waste space, in a month or so you should be
> able to stick Recant on it. Say what you like about database-backed
> filesystems, space-efficient they aren't.

Well, we all store stuff we don't need, how about automatically
throwing half of it away? I had some tape drives that used to do
that, very space efficient. I wonder if the lzip source code is still
available now the web page has gone, you could integrate it into your
filing system!

I was trying to make sense of the Lustre web pages, I'm not keen on
reading too much into any pages that are linked from a page that
states at the top that the information on them indicates what they
want to do, and not necessarily what has been done!

--
Blast off and strike the evil Bydo empire!
.

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