MiST and MIDI questions

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MiST and MIDI questions

Postby distantminds » Fri Jan 03, 2014 9:29 pm

Hello gang, Happy New Year to you all :)

i've been reading with increasing interest the main MiST thread here, and my interest has really ramped up over the last few months, It definately feels like a very creative time for atari hardware projects at the moment!

Ok, so i've got some questions! specifically with regards to MiST and MIDI. i've read the 'big' thread and also the MiST or Hatari thread (i'm a massive Hatari fan also btw ;) ) and have picked up a few midi related things, but i'm still a bit uncertain about the lay of the land. I hope you don't mind if I bust off a couple of questions.

How is MIDI working out on the MiST? Does it work? is it atari-tight timing?
Does Cubase run (specifically I guess the cracks floating around.) Does the real-deal Cubase stand a chance of working one day (ie. dongle)
Does this MIDI breakout board exist? i read some posts with people requesting it.


In my head I can picture an Akai frankensampler with a built-in MiST :P

thanks alot for any thoughts on these questions :)

damo

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Re: MiST and MIDI questions

Postby MasterOfGizmo » Sat Jan 18, 2014 7:56 pm

Sorry for the late reply. But heer we go:

distantminds wrote:How is MIDI working out on the MiST? Does it work? is it atari-tight timing?

It works, here's a video: http://www.youtube.com/watch?v=phqs-UzhIL4 The timing is pretty close to a real ST.

distantminds wrote:Does Cubase run (specifically I guess the cracks floating around.) Does the real-deal Cubase stand a chance of working one day (ie. dongle)

Yes, cracked versions run. Uncracked ones don't. If if you could attach the dongle to the MIST (which you can't), then the Cubase 2 dongle wouldn't work as it needs a 100% perfect 68000 timing emulation. That's the reason why Cubase2 also doens't run on the TT or Falcon with the 68030. The Cubase2 dongle for the same reason cannot be implemented inside the FPGA. Actually i can implement it and i have implemented it as i analysed the inner workings of the Cubase2 dongle, but the TG68 68000 CPU core used in the MIST isn't perfect enough to cope with it.

Cubase3 probably is a different beast and i am pretty sure that dongle can be implemented inside the FPGA. But i have never had one of those dongles in my hand, so i can't tell for sure.

distantminds wrote:Does this MIDI breakout board exist? i read some posts with people requesting it.

I have just redesigned the board, so that it should now fit into the MIST case. But this is still a do-it-yourself thing as explained here: http://code.google.com/p/mist-board/wiki/MidiAddon

Actually i haven't used MIDI on the MIST for quite some time now.
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Re: MiST and MIDI questions

Postby mahen » Fri Apr 04, 2014 2:39 pm

Hi !

Some updates on the Amiga support for the MIDI interface ?

I would like to give OctamedSS and others a try... And also, if it could be accessed from Blitz it could come in handy !

Cheers ! & thanks again to all involved !
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Re: AW: MiST and MIDI questions

Postby MasterOfGizmo » Fri Apr 04, 2014 3:20 pm

mahen wrote:Some updates on the Amiga support for the MIDI interface ?


I've never owned an amiga and especially never used midi on one. Mmrobinson5 from the minimig.net forum has midi running on some home made setup pretty similar to the mist. So this is definitely possible without too much effort. But i focus on the atari st atm
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Re: MiST and MIDI questions

Postby mahen » Sun Apr 06, 2014 8:06 pm

Thanks for your reply !

I'm pretty sure the answer will be "no", but does any of you guys build MIDI interfaces for the MiST or is it "DIY" only ?

I'm more an Amiga guy but using the ST core as a MIDI YM synthesizer could be pretty interesting !
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Re: MiST and MIDI questions

Postby MasterOfGizmo » Fri May 02, 2014 7:47 pm

I have a few prototypes left. But mounting them needs some soldering and metal work as mentioned in the other thread.
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Re: MiST and MIDI questions

Postby AnakiMana » Mon Jul 14, 2014 10:19 pm

Lotharek has a new MIST for sale in his online store now, which includes the MIDI interface. "MIST REVISED 2k14 with MIDI add-on in high quality METAL CASE"

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Re: MiST and MIDI questions

Postby knabo » Wed Aug 20, 2014 11:51 pm

Since getting the new MiST with MIDI I've been experimenting with lots of different MIDI programs. It's really incredible how compatible this little machine is and how much fun it is to wire it up to MIDI gear and set an algorithmic phrase generator to let loose... heavy nostalgia. I wanted to share some of my notes in case anyone else is doing the same. I'm only listing 100% reproducible bugs here, not the odd glitch or two.

  1. Using my Roland PC-200 mkII as a MIDI controller, the MiST seems to only capture a few notes at a time, somewhat randomly, and I need to wait a second or two before playing any more notes or they aren't registered... it's erratic. However, when I use my Yamaha PSS480 as a controller, it works perfectly. I think this is because the PSS480 doesn't send any velocity/modulation/etc. only note on and note off (and maybe the occasional program change).
  2. Timing in Master Tracks Pro and Machina Musica is 1:1, whereas Cubase and Live Plus (both of which use MROS) seem to lose 5 or 6 seconds in a minute.
  3. Cubase 2.01 (MCA Crack): If you start a new arrangement, create a new track and a pattern, and then go to edit it the pattern, it will work fine. You can draw in notes, pitch bend, modulation, etc. and they all play back as they should. If you keep your changes to that pattern and then play it back from arrangement mode it still works fine. But when you go back into that pattern to edit it (whether in the key, score, drum editors) it won't play in edit mode, only in arrangement mode. You can press the play button and the playhead will glide across your pattern, but no MIDI data will be output (the little MIDI output box that should be flashing in the bottom right shows no activity). This makes it basically unusable for manual sequencing because you can't listen to your pattern as you edit it. I've tried multiple copies and they've all given me this same behavior... has anyone else experienced this?
  4. Cubase 3.01 (MCA Crack): In step editor, the draw tool will randomly stop drawing notes. It will start working normally again after a few seconds or sometimes up to a minute or longer. I've never played with this version too much in the past, so I'm not sure if this is a bug with the crack or with the MiST.

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Re: MiST and MIDI questions

Postby MasterOfGizmo » Wed Sep 03, 2014 2:26 pm

After several weeks of non-atari core hacking i am now returning to my precious atari st core :-)

One thing i'd really like to fix is the MIDI as this is one part on the MIST that really makes a difference over emulators.

First thing will be the speed issue. I'll first have a close look at the MFP timers as these are the usual time source. In theory even the system clock should then show the same symptom.
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Re: MiST and MIDI questions

Postby MasterOfGizmo » Wed Sep 03, 2014 7:13 pm

I found and fixed an off-by-one bug in the MFP timers. When e.g. a prescaler of 10 was set (as cubase does) then it actually counted from 0 to 10 which aren't ten steps but eleven resulting in the MFP being 10% too slow.

I fixed that and cubase replay speed looks perfect now.
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Re: MiST and MIDI questions

Postby MasterOfGizmo » Wed Sep 10, 2014 9:40 am

A few days ago i fixed the MFP timer issue which made MIDI replay run 10% too slow.

There always was this "hack" i needed to get MIDI replay stable. I found the actual problem and fixed it, so MIDI replay now works without any hack.

And finally i found a small glitch in the ACIA receiver which causes bytes to be lost if data was to be received at full speed. This has also been fixed and in my tests MIDI in with cubase seems to work reliably.

In summary all known MIDI issues with the MIST board have hopefully been fixed :D
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Re: MiST and MIDI questions

Postby Eero Tamminen » Wed Sep 10, 2014 6:06 pm

I don't have MiST yet, but this is yet another great reason to consider ordering one. :-)

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Re: MiST and MIDI questions

Postby teevee » Wed Sep 10, 2014 6:58 pm

MasterOfGizmo wrote:A few days ago i fixed the MFP timer issue which made MIDI replay run 10% too slow.

There always was this "hack" i needed to get MIDI replay stable. I found the actual problem and fixed it, so MIDI replay now works without any hack.

And finally i found a small glitch in the ACIA receiver which causes bytes to be lost if data was to be received at full speed. This has also been fixed and in my tests MIDI in with cubase seems to work reliably.

In summary all known MIDI issues with the MIST board have hopefully been fixed :D


Interesting :)
Do you have some proof that it works? :) (demo, where you use the machine as master sequencer)

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Re: MiST and MIDI questions

Postby MasterOfGizmo » Sat Sep 13, 2014 5:29 am

You might take other peoples word in the other threads.

But if you don't trust the developers then the device is probably not the right thing for you.
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Re: MiST and MIDI questions

Postby INSPECTOR77 » Tue Sep 23, 2014 3:27 pm

MasterOfGizmo wrote:A few days ago i fixed the MFP timer issue which made MIDI replay run 10% too slow.

There always was this "hack" i needed to get MIDI replay stable. I found the actual problem and fixed it, so MIDI replay now works without any hack.

And finally i found a small glitch in the ACIA receiver which causes bytes to be lost if data was to be received at full speed. This has also been fixed and in my tests MIDI in with cubase seems to work reliably.

In summary all known MIDI issues with the MIST board have hopefully been fixed :D



This is a great update! now with midi 100% working i NEED a MiST!!! Thanks
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Re: MiST and MIDI questions

Postby novoline » Wed Sep 24, 2014 12:07 am

Yay, I've joined the MiST crew!
I got two MiSTs via Lotharek yesterday and have been exploring the MIDI as well as failing to get a hard drive image working.

I did some tests to see if the MIDI behaviour was consistent and I noticed two things, but the second one may be such a specialised case that it won't be worth fixing, but I hope so.

1) The MIDI out lacks enough current that all MIDI equipped instruments have, the (i think) 5 volts that powers certain midi equipment, such as a midi merger or splitter. I don't know if this is a limitation by the fact that the power supply is a USB charger(low amps), or if this is an oversight in the circuit modelling.

2) Speed is slightly slower than a normal Atari.
I usually use two ST's (or Mega ST or STE, it never matters,I have each kind, some with 1mb RAM and others with 4) both running the same software and sync them by hitting "play" (the spacebar.) The Ataris will stay in sync for as long as I let them run. I did a test earlier this year where I let two Ataris run for 4 hours after a spacebar sync. They stayed in time/sync the whole time.
Today I tried a similar test with the MiSTs and Ataris. It didn't take long (about 30 seconds) to notice that the MiST runs a few microseconds slower than the Atari. The two MiSTs stay synced together just as two Ataris would, but when I throw a real Atari ST in the mix, I can hear the Atari's sounds coming in earlier on the beat ever so slowly.
I took the liberty of recording this behaviour in the most controlled environment that was possible, so hopefully some measurements could be made to get an idea of exactly how much slower the MiSTs are running (and maybe fixed :P ).
The file below (mp3, 19mb) is ~20minutes, the audio is a 4/4 ~92bpm pulse of a snare drum in the left channel coming from an Atari Mega ST(via a drum expander triggered by MIDI), and a kick drum from one MiST(midi to drum exp.) in the right channel. Occasionally I bring in the other MiST (who sounds a snare drum as well) to see if it was remaining in sync with the other MiST (and it did.) At the end of the audio file you can hear that the St's snare drum is now a half beat in front of the (MiST's) kick drum.

file -> http://we.tl/UmQdP51Gdr

It's a minor disadvantage, but having them run identical speed to the Atari (if this is possible?) would enable me to swap ataris and mists around in my studio or on stage like they are the same machine. As it is now I need to keep them on different teams. We ARE talking about a half beat every 20 minutes here so its very small , but thats no good for a musician, or the music!

The next test I'll do regarding this will be to see if the MiST MIDI Clock is detected at a different speed than the ST within a modern PC's DAW. When I send MIDI clock from an ST, I always get erratic numbers: like if I'm running ~92bpm, a modern software package's clock detection will jitter around that, going down to 91 and up to 93. I don't know if this reflects bad modern software or unsteady clock in the Atari, but since the ST's stay in sync with each other it never concerns me.
\
Cheers
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Re: MiST and MIDI questions

Postby INSPECTOR77 » Wed Sep 24, 2014 10:51 am

Interesting........Did you test with diferents bpm? , did you test a external midi keyboard?

Now in using a Ste (midi) in sync with a Roland vs-880 (audio) , and i´d like to replace the Ste for the MiST, so i need a perfect sync time...


Thanks!!!
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Re: MiST and MIDI questions

Postby MasterOfGizmo » Wed Sep 24, 2014 1:46 pm

novoline wrote:1) The MIDI out lacks enough current that all MIDI equipped instruments have, the (i think) 5 volts that powers certain midi equipment, such as a midi merger or splitter. I don't know if this is a limitation by the fact that the power supply is a USB charger(low amps), or if this is an oversight in the circuit modelling.


It's not a problem with the power supply i am sure. We need a little background here:

MIDI was designed when 5V was the voltage being used in computers. Today it's 3.3V and less what most computers use internally. MIDI implementations struggle with this.

If you have a look at the MIST MIDI addon board documentation at https://code.google.com/p/mist-board/wiki/MidiAddon you'll see the resistors R1 and R5 each being 56ohms and both limiting the current that flows over pins 1 and 3 on connector X1 (MIDI OUT). That's where the board drives your gear.

The Atari ST was a 5V device and according to http://dev-docs.atariforge.org/files/52 ... ematic.pdf used 220 Ohms in the same place (R77 and R80).

On the receiving side there's always a 220 ohms resistor (R3 on the MIST and R76 in the Atari ST)

This limits the current to 5V/3*220ohms = 7.5mA in short circuit or 5mA if the opto couplers LED on the receiver side drops 1.7V as (5V-1.7V)/3*220ohms = 5mA. This is what the MIDI standard assumes.

A diode with a voltage drop of 1.7V is driven by the MIST with (3.3V-1.7V)/(2*56 + 220) = 4.8mA. This is a difference of 0.2mA and is actually pretty close and should work. But what if your device has a LED with e.g. 2V voltage drop? Then you have 4.5mA with the 5V circuit and 3.9mA on the 3.3V cicruit. The difference is now 0.6mA. So the influence of the voltage drop of receiver LED becomes bigger in the 3.3V circuit.

What can you do? Do you know how to use a soldering iron? Are you willing to use it? Then you could lower the values of R1 and R5 on your MiSTs MIDI add-on board. I think the new MIDI boards you guys have look a little bit different than the ones i have depicted on my page. I'll update that asap. But you could try to add 100ohms on top of R1 and R3. This will effectively lower both resistors to 35 ohms and increase the current to (3.3-1.7)/(2*35 +220) = 5.5mA with a 1.7V LED or (3.3-2)/(2*35+220)=4.5mA with a 2V LED.

The additional current shouldn't hurt any device and may help those of your devices that have difficulties with the MIST. It also doesn't hurt the MiST. It can drive that current (a complete MiST draws about 300-400mA).

novoline wrote: Today I tried a similar test with the MiSTs and Ataris. It didn't take long (about 30 seconds) to notice that the MiST runs a few microseconds


We can probably work on that one. The main clock source inside the MISTs Atari core is a PLL. This is basically a "tunable clock generator" and one thing this generates is the MFP clock which in turn is the clock Atari ST programs usually derive their timing from. I wonder if you could give me a number like "the MIST should run at factor 1.05 of the speed i currently see". I could try to adjust that. But there are limits. I cannot really do any value at any precision. But i can try.

According to the data sheet mentioned above the Atari STs MFP is clocked at 2.4576 MHz. The MISTs PLL is configured to the closest value i could achieve which is 2.457173 MHz giving an error of slightly less than 0.02 percent. This is pretty exactly an error of 1 second per 1.5 hours or 5 milliseconds in 30 seconds. Is this in the range of the error you rencounter?
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Re: MiST and MIDI questions

Postby knabo » Wed Sep 24, 2014 2:10 pm

INSPECTOR77 wrote:did you test a external midi keyboard?


I've been using the MiST with my Roland PC-200 mkII (and outputting to an SC-55), and everything works great: polyphony, velocity, pitch bend, modulation, program change, etc. Only thing I haven't had the time to try is sysex dumps, but I can't imagine there would be a problem... I'll be testing it with my TG-77 shortly.

Also, has anyone had any luck getting Notator/Creator to run with any reliability? The MCA crack of 3.0 I have throws up lots of odd errors, which I think is the crack's fault, but hard to tell.

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Re: MiST and MIDI questions

Postby foft » Wed Sep 24, 2014 4:29 pm

@Till: Could the pll accuracy be increased by cascading two plls? Cyclone iii supports this and I've used it in a few cases.

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Re: MiST and MIDI questions

Postby novoline » Wed Sep 24, 2014 6:11 pm

MasterOfGizmo wrote:
What can you do? Do you know how to use a soldering iron? Are you willing to use it? Then you could lower the values of R1 and R5 on your MiSTs MIDI add-on board. I think the new MIDI boards you guys have look a little bit different than the ones i have depicted on my page. I'll update that asap. But you could try to add 100ohms on top of R1 and R3. This will effectively lower both resistors to 35 ohms and increase the current to (3.3-1.7)/(2*35 +220) = 5.5mA with a 1.7V LED or (3.3-2)/(2*35+220)=4.5mA with a 2V LED.


I'm happy to solder, if fixing the problem is that simple then i'll head on over to Conrad tomorrow! :D

Which are you suggesting, to lower the values of R1 and R5 or add to R1 and R3? I don't understand the LED part, are you talking about the LEDs inside the MiST or a LED inside a powered MIDI device or something else?
MasterOfGizmo wrote:
novoline wrote: Today I tried a similar test with the MiSTs and Ataris. It didn't take long (about 30 seconds) to notice that the MiST runs a few microseconds


We can probably work on that one. The main clock source inside the MISTs Atari core is a PLL. This is basically a "tunable clock generator" and one thing this generates is the MFP clock which in turn is the clock Atari ST programs usually derive their timing from. I wonder if you could give me a number like "the MIST should run at factor 1.05 of the speed i currently see". I could try to adjust that. But there are limits. I cannot really do any value at any precision. But i can try.

According to the data sheet mentioned above the Atari STs MFP is clocked at 2.4576 MHz. The MISTs PLL is configured to the closest value i could achieve which is 2.457173 MHz giving an error of slightly less than 0.02 percent. This is pretty exactly an error of 1 second per 1.5 hours or 5 milliseconds in 30 seconds. Is this in the range of the error you rencounter?


In this case wouldn't the MiST be running faster than the ST? I've found that its running slightly slower than the ST. I'll try and do very precise measurements and let you know.
If you have time i encourage you to download that mp3 file, you can see/hear the slower MiST creep along.

INSPECTOR77 wrote:Interesting........Did you test with diferents bpm? , did you test a external midi keyboard?

Now in using a Ste (midi) in sync with a Roland vs-880 (audio) , and i´d like to replace the Ste for the MiST, so i need a perfect sync time...
Thanks!!!


Havent tested different BPMs, I thought of that in fact, if faster BPM will make the delay be shorter or will it be the same. But I ran out of time. As mentioned above i'm going to test more and record results.

Testing an external keyboard in what sense? In my setup all synths and drums are simply sound modules, the only clock and midi source is the ST. Do you mean to test how the MiST handles as MIDI Clock slave vs a real ST? I'd be happy to help -- if it weren't for feedback on this forum and Till's work, I wouldn't even have bought my MiSTs yet!
I can probably do whichever testing you need when i find the time, just tell me exactly what you're looking for, however I need to get my HD image problem worked out first, and in a week I go on a 3 week trip away from most of my gear. :coffe:

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Re: MiST and MIDI questions

Postby MasterOfGizmo » Wed Sep 24, 2014 7:13 pm

Cascading two plls or even using a seperate one just for the mfp clock is what I'll do next to increase the mfp precision.

And no, the mist wouldn't be faster. It runs basically synchronous to the mfps clock. If the mfp clock is slow (and it is by 0.02%) then the software running in sync with this is also slow.

And finally the leds. There is an optocoupler inside every midi receiver. The receiving part of this is a led. So I am talking about a led on receiver side which is driven by the sender. I suggest to add 100 ohms on top of each of the two 56 ohms resistors. That way you don't have to unsolder anything and don't risk damaging the board.
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Re: MiST and MIDI questions

Postby novoline » Wed Sep 24, 2014 7:39 pm

MasterOfGizmo wrote:And no, the mist wouldn't be faster. It runs basically synchronous to the mfps clock. If the mfp clock is slow (and it is by 0.02%) then the software running in sync with this is also slow.

Indeed! I don't know what I smoked earlier

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Re: MiST and MIDI questions

Postby MasterOfGizmo » Thu Sep 25, 2014 10:38 am

I've uploaded a new core which is supposed to be 0.001% close to a real Atari ST. This is meant to be 20 times closer to a real ST than the previous version. I didn't do much tests with this version. But please give it a try.

We are now exceeding the limits of the precision of the parts involved (in the mist as well as in the ST). Standard oscillators have a precision of typically 100ppm which is 1/10000 or 0.01%. Most devices will perform better as this is the precision quaranteed by the vendor. But no two oscillators are really identical. It only question how big the differences are.
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Re: MiST and MIDI questions

Postby novoline » Thu Sep 25, 2014 10:58 pm

MasterOfGizmo wrote:I've uploaded a new core which is supposed to be 0.001% close to a real Atari ST. This is meant to be 20 times closer to a real ST than the previous version. I didn't do much tests with this version. But please give it a try.

We are now exceeding the limits of the precision of the parts involved (in the mist as well as in the ST). Standard oscillators have a precision of typically 100ppm which is 1/10000 or 0.01%. Most devices will perform better as this is the precision quaranteed by the vendor. But no two oscillators are really identical. It only question how big the differences are.


Fantastic! Too bad for me that i just spent 2 hours taking notes on that mp3 file. :lol: (at least i multitasked with copying subfolders one by one on my HD image)
I was just about to download a graphing program and enter all the data (i took down measurements of the difference between the snare and kick for every 20 seconds for 10 minutes of audio.) Ah, the foils of no internet at work.
Cant wait to try tomorrow. great work

a glimpse:
2:00.28223 2.00.31779 0.035
2:23.43856 2:23.47861 0.040
2:35.65960 2:35.70270 0.043
2:53.66977 2:53.71681 0.047
3:13.61000 3:13.66065 0.050
3:20.04177 3:20.09402 0.052
3:32.90635 3:32.96123 0.054
3.46.41387 3.46.47115 0.057
3.51.53855 3.51.59697 0.058
4.01.82990 4.01.89069 0.060
4.11.47862 4.11.54081 0.062
4.25.98585 4.25.05163 0.065
4.35.27783 4.35.34533 0.067
4.44.92587 4.44.99541 0.069
4.57.79035 4.57.86246 0.072
5.09.36835 5.09.44295 0.074
5.24.80588 5.24.88394 0.078
5.29.95158 5.30.30000 0.078
5.31.23763 5.31.31960 0.079
5.39.59966 5.39.68020 0.080
5.46.67517 5.46.75765 0.082


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