PC still playing Amiga catchup

[koaftder]

Thought experiment:

Suppose you took an analogue joystick and used the X/Y potentiometers to control an independent left/right output volume from a oscillator (generating a note at let say several kHz)  then fed that into your basic sound card and sampled this signal at 44.1kHz. You could then calculate the RMS intensity of each channel in frames of 441 sample chunks and use that (suitably calibrated) to represent the original X and Y potentials. 441 samples at 16-bit precision would be ample data to get a decent value for the RMS intensity of a simple tone in the kHz range.

That should be pretty damn close to 1kHz sampling of your joystick position

Make sure to use single copper crystal wires, coated in platinum.

I wonder if amigaksi has ever seen what a button press looks like with an oscilloscope, or has ever had to deal with debouching. Years ago, when I first started playing around with microcontrollers, I had a simple little project I threw together, one of my first. Toggle an LED based on the state change from a pin. I'd press the button and it would randomally decide whether or not it was gonna stay lit. That drove me up the wall but I learned something. Contact switches are full of noise and ring like hell. Polling the crap out of a contact switch or tying one to an interrupt line is a waste of time. You take a sample and you move on. Even if a person could press a button 1,000 times a second, the noise floor would make it impossible to ascertain what really happened. This is one of the many reasons why people typically sample the joystick once per frame. You're not likely to have a legitimate state change in under 50ms. Sampling at higher rates just means you're picking up noise.

*edit* lol, you guys beat me to it!

[Karlos]

:lol: amigaski has forgotten that physical switches have a maximum switch frequency... any amiga joystick will use cheap switches that will switch far bellow 1khz

Perhaps his joystick is built by the folks that made these

[bloodline]

The funny part is that it's fairly common to poll the joysticks only once per VBL, which generally means every 20ms on the Amiga...

And polling at the frequency he mentions gives erroneous values - that actually means it's inferior to modern counterparts - which is even more funny considering the argument used in this discussion.

So in fact the Amiga hardware is inferior to the PC since it doesn't debounce the input signal hahaha

[shoggoth]

So in fact the Amiga hardware is inferior to the PC since it doesn't debounce the input signal hahaha

Human reaction time is also worth taking into the equation:
http://en.wikipedia.org/wiki/Reaction_time

Reaction time from visual stimulus is actially in the 200ms range, which means polling the joystick every 20ms is more than adequate.

[GadgetMaster]

Perhaps his joystick is built by the folks that made these

Be careful what you search for on the net these days. :nervous:


[EDIT]

I just realised this is my 2000th post no wonder I gained a rep power point.

[ElPolloDiabl]

"Reaction time from visual stimulus is actially in the 200ms range"

I wouldn't use wiki as an authorative source on everything.

Look at Tennis, Cricket and Baseball or Clay pigeons even. Or how about snipers?

[meega]

Yeah... I did some reaction-time tests on a BBC micro when I was about 15 years old. These days they "red-flag" sprinters who respond to the gun in less than 0.1s, because it's counted as jumping the gun - but I was able to *average* about 0.08s, with lots of 0.04-0.06s, and that included making a decision as to which hand to use to press a key in response to a square appearing on either the left or right side of the screen. If you were less than 95% accurate on 100 tests then the whole caboodle was discarded - it assumed you were guessing.

[Trev]

Not everyone can play tennis, cricket, and basebell or shoot targets. The world's fastest tennis serve crossed the court in 326ms. Nice. Regardless, ~200ms is the magic number, and it's what you need to shoot for to make something appear instanenous.

[koaftder]

"Reaction time from visual stimulus is actially in the 200ms range"

I wouldn't use wiki as an authorative source on everything.

Look at Tennis, Cricket and Baseball or Clay pigeons even. Or how about snipers?

They're describing a specific thing here. Mainly, waiting for a visual cue and making some kind of movement, and 200ms is about  right, according to everything I've read over the years. People can move faster, of course, but within limits, but not hanging on a stimulus event. Typing or walking up a flight of stairs for example. In games, it's easy to get trained to the point where you just automatically hit the right sequence of interface buttons to go through a level without even thinking. But how fast can you click a button or move a stick?

Try this: http://www.urban75.com/Mag/java7.html

Best I can do is 6 clicks a second. 166ms per click.

[AmigaHeretic]

Have you seen typical driver sets for things like graphics cards these days?

Thanks to direct support for CUDA, PhysX, OpenGL1.0 - 3.0, Direct X (up to v10), Pure Video etc, the drivers for my card alone weigh in at around 100 MB, not including tweaking tools.

The linux drivers aren't much smaller.

I don't really think that has anything to do with initalisation though.  With drivers your really are getting back to HD speed and CPU speed. Besides even it took a full second to initalize the card, with the Quad core beast, blazing fast bus speeds, and HD speeds you should be able to initialize just about everything at the same time.  Aside from the fact that many people, as some have pointed our here, this is possible.   Something QNX or Amithlon, take seconds to boot and you can access the internet, hear sound, see the desktop.


For Windows, there's also the speed that "some" apps install.  Or some Windows updates.  Windows update can take minutes just to figure out what needs to be updated.   I can render huge 3D scenes in Maya in less time.  What in the world could Windows be doing in all that time?

[Karlos]

Churning your hard disk, that's what. Rendering is usually a CPU/memory IO bound task. The bottlenecks there are small and a fast CPU/memory system will plough through such work.

Dependency resolution and all the nonsense that goes with it is generally a disk IO bound task. Modern hard disks have great transfer speeds but they don't seek much more quickly than they did years ago. If you are processing thousands of small files, the time is totally dominated by seeks and the like. The CPU will be twiddling it's virtual thumbs for a lot of it.

Having said that, yum and apt-get (to name just two) are significantly quicker. I think we just live in a world where windows is expected to be slow for these things.

[smerf]

@DonnyEMU
Well, I've no delusions about the many weaknesses of the Amiga, but to be honest, I do like the fact that I can boot it up, do a quick Google and shut it down again before my Windows system has become responsive. That's a positive asset for me, in a real situation. Don't get me wrong, the PC is probably used more than the Amiga in my world, but it takes so long for the PC to boot that I don't really use it for looking up something quickly. Hell, fiddling about on my phone's browser is usually faster, and I don't have to go upstairs

I don't like having computers turned on all the time; they generate heat and use electricity. And those hardware guys should have been able to tell you, that hibernating a computer is pretty much the same as a full shut down/start up as far as the PSU and hard drives are concerned. Sleeping might be a little less harsh on the PSU, but I'd be far more worried about the starting/stopping of the mechanical hard drives. And that's the same whether you sleep or shut down a system.

Hi,

Not only that but while your computer is sleeping the power supply keeps running and a fan in the power supply stays on pulling through air, this draw through pulls in dust, but that just brings another market to the PC world, compressed air to blow the dust out of their many heat sink fans, and air ducts.

smerf

[juan_fine]

Hi,

Not only that but while your computer is sleeping the power supply keeps running and a fan in the power supply stays on pulling through air, this draw through pulls in dust, but that just brings another market to the PC world, compressed air to blow the dust out of their many heat sink fans, and air ducts.

smerf

Ummm, time to wake up, it's 2009! My computer's power supply and fans power down to something like 5% or so when it sleeps. Even the pretty lights go out...

[smerf]

Ummm, time to wake up, it's 2009! My computer's power supply and fans power down to something like 5% or so when it sleeps. Even the pretty lights go out...

Hi,

@juan_fine,

Don't really know about that but my modern day computer keeps the fan in the power supply running when it sleeps, it may slow down some but still produces enough noise to bother my wife when she is trying to sleep, so I have gotten used to turning my computer off. By the way this is a totally year old machine built to play the most modern day games at very fast frame rates, equal to maximum pc test point computer. And by the way pretty blue lights still stay on after shutdown, the only way to get rid of them is to hit the main power switch off on the power supply, and yes juan_fine, my computer does have an off switch. Don't have to wait for winblows or linux to shut it down, but this is not advised with these two OS's

smerf

[the_leander]

Be careful what you search for on the net these days. :nervous:


[EDIT]

I just realised this is my 2000th post no wonder I gained a rep power point.

Gratz!

I guess this means I'm going to have to really put my back in to posting more regularly again!

:laughing:

[Hammer]

Hi,

Not only that but while your computer is sleeping the power supply keeps running and a fan in the power supply stays on pulling through air, this draw through pulls in dust, but that just brings another market to the PC world, compressed air to blow the dust out of their many heat sink fans, and air ducts.

smerf

My laptop's sleep mode shuts down the fan.