So, what's the current status of everything?


One Moment please: You allready play some Emulators?? Dos this means our MP Pyra want be just Doorstoppers in Two Months ?? , Or are they only Emus from the Debian Repo who needs to Optimice ??

Just installed via standard Debian Repo. Stella works fine, but other emulators like Nestopia use GL for graphics output... and as that's currently being done in software, it's really slow. :)
But yeah, DOSBox and Stella work fine :)
 
Stella was for Atari VCS ?? So from Pacman up to these at these whyred XXX games ?? (at this time it was a scandal, today its just funny)..

Dosbox is cool, when i find my few Game Disquettes, as i now have a USB 3,5 ° Disk Drive..

Unfortunaly, on Pandora, Dosbox was too divicult for me, as i cant remember it had a Option to just pick up the Games from a Folder via GUI and Run them..

The C64 Emu had a Option to just chose a File, ..

Maybe im not that good as a Pandora Owner..

EDIT: OK, just looked at Wikipedia: Stella is for VCS /2600 Atari..
 
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I don't understand something from the device pictured on the right. Those squares at the bottom appear to be position for stereo speakers - in portrait mode. Not much room for any separation of the audio that way. Wouldn't it make more sense to place those top and bottom? The device would then have stereo sound in landscape mode and have better symmetry.

Stereo in landscape mode makes perfect sense - movies, games, whatnot.
Stereo in portrait mode though? I can't think of any reason for it.
 
And on an update: While the DigiKey package arrived, the part I needed to modify the Display board to change the prototypes to basically the final version wasn't in the package. Meeeh,
So I can't update the display boards.

But I still can check and work on the mainboards, as I have everything for that here :)

Glad to see that there is movement on these. My questions are casual and based on curiosity - don't bother to answer if you don't have time to deal with it. Although I'm obviously looking forward to the prototype, don't let the prototypes prevent you from your more profitable ventures or from having a Merry Christmas and Happy New Year and spending some good quality time with your family.

If I recall right on the mainboards - there were a few very tiny resistors that were not positioned right and had to be removed, cleaned up, repositioned and re-soldered on. Pretty close to microsurgery with a soldering iron is my interpretation. Is that what you are working on or was there something more to it?

Display boards modifications? I wasn't aware that there was much left to do on those. Hope the parts come in without drama.

Is that it then? Are you comfortable that you have the plastics sorted out?

Thanks again!
 
I'm hardly an expert, but I always imagined that modern audio processors do some sort of interpolation to bring the digital signal up to the DACs native sample-rate, and then filtered the signal in analogue-land to eliminate any interesting artefacts left over from the time quantisation.

Trying to interpret a sample-stream as a stepped wave seems clearly the worst option for audio. Real sounds don't have sharp edges in them like that! (Except, perhaps, for detonations and extremely violent impacts?). Other things aside, you'll have trouble finding a loudspeaker that can accurately reproduce step functions...

You really, really need to watch at least the second video I posted links to above earlier. Filtering is actually far easier in the digital domain*, and the output of a DAC is not square waves - essentially the digital numbers give the coefficients of different frequencies and magnitudes of sine waves that need to be added together to give the intended output. This has the side effect that a DAC cannot reproduce a square wave, as it would need to sum an infinite series of sine waves to get a step function.

e.g. High quality Notch filters are expensive in the analogue domain, but trivial to do digitally.
 
Did you read the whole message or did you just stop to read when you want?

I did. Your message said «Comparing x86 with ARM. Nice. Edit: Wrong FORUM, lol».

Obviously from previous message (not yours) I understand he compares actual PC x86 CPU with actual mobile ARM CPU, and we can't compare them in a lot of cases. If you'd write «Comparing actual PC x86 with actual mobile ARM» you would be correct.

(Although I think it may be you wanted to point that x86 vs ARM is not a matter for this forum)

The question I wanted to point, the one you didn't get: it is not a problem/limitation of ARM architecture but a limitation on power (energy-heat-etc). If you had a x86 cell phone/mobile (and we did: there were x86 smartphones), you would have the same problem: power.

There is a lot of misconception about ARM (I have seen all types of misconception it).

An ARM CPU can be as powerful as a x86 CPU, even more powerful, if it is built with same number of transistors, integration, etc. And I know about some ARM CPU with more power than some x86 CPU (both around same age; obviously if you compare CPUs too far in time, it losses sense).
 
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the output of a DAC is not square waves (...) a DAC cannot reproduce a square wave

Any DAC I've ever worked with has been perfectly able to output square waves (ignoring non-zero rise and fall times of course). A DAC basically just converts a number on an input to a voltage (usually, but it could just as well be a current) on its output - if the number on the input changes between the minimum and maximum all the time then the DAC will happily output a square wave for you.
 
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So dit the right Parts from Digikey finaly arived ?? , Cool then its not that far away from hopefully Picturefull Reviews from the Protoyph Guys ^^

Hopefully Trump ditnt make a Ameriexid so they can still be shipped to the Greatest Country in the World (whit the Biggest Atombutton).. ^^ (I want a discussion about the Pyra in this Thread, dotnt derail it whit politics..)..
 
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@Akko "perfectly" and "ignoring non-zero ..." doesn't go together. If a DAC/DACs are capable of outputting square waves depends on the tolerances you're prepared to allow. Or in other words, DACs can approximate square waves, but cannot output perfect ones - especially not fine steps at the sample rate. And, this is, what Confuzzles was saying, as I understand it.
 
@Akko "perfectly" and "ignoring non-zero ..." doesn't go together. If a DAC/DACs are capable of outputting square waves depends on the tolerances you're prepared to allow. Or in other words, DACs can approximate square waves, but cannot output perfect ones - especially not fine steps at the sample rate. And, this is, what Confuzzles was saying, as I understand it.

That's nitpickery, *nothing* can output *perfect* square waves. A maximum step from say 0V to 5V at 44kHz is ~0.22V/µs (if I didn't mess that up, I'm still not quite awake ^^) which is definitely doable with a good DAC. The first one I found right now can do 35V/µs for example.

What *I* was mainly trying to say is that (common) DACs do not output several added sinus waves but rather a voltage defined by a series of input values directly converted to a series of output values.
 
What *I* was mainly trying to say is that (common) DACs do not output several added sinus waves but rather a voltage defined by a series of input values directly converted to a series of output values.
Try outputting a constant voltage using one - you'll be surprised.
 
Try outputting a constant voltage using one - you'll be surprised.

I have - no surprises there. A DAC fed a constant input value should have no problems outputting a constant voltage. If it can't do that, something is wrong with it. I'm not sure what kind of DAC you've used...
 
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