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Old 06-25-2010, 01:36 PM
Ralf Mardorf
 
Default basic MIDI note-on/note-off questions

On Fri, 2010-06-25 at 14:38 +0200, Ralf Mardorf wrote:
> On Fri, 2010-06-25 at 08:29 -0400, Paul Davis wrote:
> > On Fri, Jun 25, 2010 at 6:55 AM, James Morris <james@jwm-art.net> wrote:
> > > Hi,
> > >
> > > I keep getting surprised at some of the most basic problems I run
> > > into... This time, processing order.
> >
> > just remember that in "real" MIDI, nothing can be simultaneous. its a
> > serial protocol without timestamps. with traditional serial MIDI, the
> > time interval between bits and bytes is also fixed, creating a fixed
> > minimal interval between any two note on/off messages.
>
> In addition, the UART gives information about being ready to send. It's
> not fixed to e.g. 1ms. There's a register giving this information.

Note, there's nothing fixed, the limitation is just for the max Baud
MIDI is able to do. Regarding to the term 'fixed' UART is for 'Universal
Asynchronous Receiver Transmitter', the important word is
'Asynchronous'. We are talking about microseconds, taking care about the
CTS and RTS registers. Regarding to all that MIDI jitter, I wonder if
ALSA seq, might has to do with it. I don't know, perhaps there are
issues for USB specifications, but maybe there's something bad for this
'timestamp' routs.

*?*

I programmed on Assembler directly using the UART and there never was
jitter.

Could this be a reason for MIDI jitter using Linux or has it nothing to
do with it? Because, at the other hand there's no jitter internal the
studio in the box.

*?*

Ralf

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Old 06-25-2010, 01:51 PM
Ralf Mardorf
 
Default basic MIDI note-on/note-off questions

On Fri, 2010-06-25 at 15:36 +0200, Ralf Mardorf wrote:
> On Fri, 2010-06-25 at 14:38 +0200, Ralf Mardorf wrote:
> > On Fri, 2010-06-25 at 08:29 -0400, Paul Davis wrote:
> > > On Fri, Jun 25, 2010 at 6:55 AM, James Morris <james@jwm-art.net> wrote:
> > > > Hi,
> > > >
> > > > I keep getting surprised at some of the most basic problems I run
> > > > into... This time, processing order.
> > >
> > > just remember that in "real" MIDI, nothing can be simultaneous. its a
> > > serial protocol without timestamps. with traditional serial MIDI, the
> > > time interval between bits and bytes is also fixed, creating a fixed
> > > minimal interval between any two note on/off messages.
> >
> > In addition, the UART gives information about being ready to send. It's
> > not fixed to e.g. 1ms. There's a register giving this information.
>
> Note, there's nothing fixed, the limitation is just for the max Baud
> MIDI is able to do. Regarding to the term 'fixed' UART is for 'Universal
> Asynchronous Receiver Transmitter', the important word is
> 'Asynchronous'. We are talking about microseconds, taking care about the
> CTS and RTS registers. Regarding to all that MIDI jitter, I wonder if
> ALSA seq, might has to do with it. I don't know, perhaps there are
> issues for USB specifications, but maybe there's something bad for this
> 'timestamp' routs.
>
> *?*
>
> I programmed on Assembler directly using the UART and there never was
> jitter.
>
> Could this be a reason for MIDI jitter using Linux or has it nothing to
> do with it? Because, at the other hand there's no jitter internal the
> studio in the box.
>
> *?*
>
> Ralf

I can't remember, perhaps CTS and RTS are flags in one register and
maybe they have other acronyms , anyway, this is the important stuff.
Pedro Lopez-Cabanillas did post the technical specifications.

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Old 06-25-2010, 08:02 PM
Ralf Mardorf
 
Default basic MIDI note-on/note-off questions

Hi

I guess no answer is an answer .

There are several ways to program for asynchronous serial interfaces,
but there's only one way regarding to real time MIDI.

When I programmed on Assembler in the 80ies I directly talked to the
UART, and request CTS/RTS for every single byte.

It's also possible not to use CTS/RTS for every single byte, but than
you need to add headroom for the time. While it wouldn't be such a
drama, if 1ms headroom would be 1ms, it's a drama because for such a
long time a lot of IRQs are able to produce jitter, but a constant
latency.

I guess the MIDI coders for Linux did a bad job. I might be wrong, but
as I said before, getting no answer is getting an answer .

Hopefully I'm just paranoid and wrong .

Cheers!

Ralf

-------- Forwarded Message --------
From: Ralf Mardorf <ralf.mardorf@alice-dsl.net>
To: Paul Davis <paul@linuxaudiosystems.com>
Cc: James Morris <james@jwm-art.net>, Linux Audio Developers
<linux-audio-dev@lists.linuxaudio.org>, 64studio-users
<64studio-users@lists.64studio.com>
Subject: Re: [LAD] basic MIDI note-on/note-off questions
Date: Fri, 25 Jun 2010 15:51:13 +0200

On Fri, 2010-06-25 at 15:36 +0200, Ralf Mardorf wrote:
> On Fri, 2010-06-25 at 14:38 +0200, Ralf Mardorf wrote:
> > On Fri, 2010-06-25 at 08:29 -0400, Paul Davis wrote:
> > > On Fri, Jun 25, 2010 at 6:55 AM, James Morris <james@jwm-art.net> wrote:
> > > > Hi,
> > > >
> > > > I keep getting surprised at some of the most basic problems I run
> > > > into... This time, processing order.
> > >
> > > just remember that in "real" MIDI, nothing can be simultaneous. its a
> > > serial protocol without timestamps. with traditional serial MIDI, the
> > > time interval between bits and bytes is also fixed, creating a fixed
> > > minimal interval between any two note on/off messages.
> >
> > In addition, the UART gives information about being ready to send. It's
> > not fixed to e.g. 1ms. There's a register giving this information.
>
> Note, there's nothing fixed, the limitation is just for the max Baud
> MIDI is able to do. Regarding to the term 'fixed' UART is for 'Universal
> Asynchronous Receiver Transmitter', the important word is
> 'Asynchronous'. We are talking about microseconds, taking care about the
> CTS and RTS registers. Regarding to all that MIDI jitter, I wonder if
> ALSA seq, might has to do with it. I don't know, perhaps there are
> issues for USB specifications, but maybe there's something bad for this
> 'timestamp' routs.
>
> *?*
>
> I programmed on Assembler directly using the UART and there never was
> jitter.
>
> Could this be a reason for MIDI jitter using Linux or has it nothing to
> do with it? Because, at the other hand there's no jitter internal the
> studio in the box.
>
> *?*
>
> Ralf

I can't remember, perhaps CTS and RTS are flags in one register and
maybe they have other acronyms , anyway, this is the important stuff.
Pedro Lopez-Cabanillas did post the technical specifications.


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Old 06-25-2010, 08:13 PM
Ralf Mardorf
 
Default basic MIDI note-on/note-off questions

On Fri, 2010-06-25 at 22:02 +0200, Ralf Mardorf wrote:
> Hi
>
> I guess no answer is an answer .
>
> There are several ways to program for asynchronous serial interfaces,
> but there's only one way regarding to real time MIDI.
>
> When I programmed on Assembler in the 80ies I directly talked to the
> UART, and request CTS/RTS for every single byte.
>
> It's also possible not to use CTS/RTS for every single byte, but than
> you need to add headroom for the time. While it wouldn't be such a
> drama, if 1ms headroom would be 1ms, it's a drama because for such a
> long time a lot of IRQs are able to produce jitter, but a constant
> latency.
>
> I guess the MIDI coders for Linux did a bad job. I might be wrong, but
> as I said before, getting no answer is getting an answer .
>
> Hopefully I'm just paranoid and wrong .
>
> Cheers!
>
> Ralf

PS:

I'm not sure, possible even it's needed to check CTS/RTS for the UART at
all events (a long time ago since the 80ies), anyway, there is the
possibility to control the UART with major priority by directly talking
to it, or by using blabla seq talking to blabla serial interface handler
written on C, were nobody knows what time consuming = IRQ allowing
headroom it will produce. I suspect incompetent programming at least as
one part for the hw MIDI jitter issue.
I guess MIDI on Linux isn't programmed for rt threads.

BUT I don't know, nobody did reply.

> -------- Forwarded Message --------
> From: Ralf Mardorf <ralf.mardorf@alice-dsl.net>
> To: Paul Davis <paul@linuxaudiosystems.com>
> Cc: James Morris <james@jwm-art.net>, Linux Audio Developers
> <linux-audio-dev@lists.linuxaudio.org>, 64studio-users
> <64studio-users@lists.64studio.com>
> Subject: Re: [LAD] basic MIDI note-on/note-off questions
> Date: Fri, 25 Jun 2010 15:51:13 +0200
>
> On Fri, 2010-06-25 at 15:36 +0200, Ralf Mardorf wrote:
> > On Fri, 2010-06-25 at 14:38 +0200, Ralf Mardorf wrote:
> > > On Fri, 2010-06-25 at 08:29 -0400, Paul Davis wrote:
> > > > On Fri, Jun 25, 2010 at 6:55 AM, James Morris <james@jwm-art.net> wrote:
> > > > > Hi,
> > > > >
> > > > > I keep getting surprised at some of the most basic problems I run
> > > > > into... This time, processing order.
> > > >
> > > > just remember that in "real" MIDI, nothing can be simultaneous. its a
> > > > serial protocol without timestamps. with traditional serial MIDI, the
> > > > time interval between bits and bytes is also fixed, creating a fixed
> > > > minimal interval between any two note on/off messages.
> > >
> > > In addition, the UART gives information about being ready to send. It's
> > > not fixed to e.g. 1ms. There's a register giving this information.
> >
> > Note, there's nothing fixed, the limitation is just for the max Baud
> > MIDI is able to do. Regarding to the term 'fixed' UART is for 'Universal
> > Asynchronous Receiver Transmitter', the important word is
> > 'Asynchronous'. We are talking about microseconds, taking care about the
> > CTS and RTS registers. Regarding to all that MIDI jitter, I wonder if
> > ALSA seq, might has to do with it. I don't know, perhaps there are
> > issues for USB specifications, but maybe there's something bad for this
> > 'timestamp' routs.
> >
> > *?*
> >
> > I programmed on Assembler directly using the UART and there never was
> > jitter.
> >
> > Could this be a reason for MIDI jitter using Linux or has it nothing to
> > do with it? Because, at the other hand there's no jitter internal the
> > studio in the box.
> >
> > *?*
> >
> > Ralf
>
> I can't remember, perhaps CTS and RTS are flags in one register and
> maybe they have other acronyms , anyway, this is the important stuff.
> Pedro Lopez-Cabanillas did post the technical specifications.
>


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Old 06-25-2010, 09:05 PM
Gustin Johnson
 
Default basic MIDI note-on/note-off questions

On 10-06-25 02:02 PM, Ralf Mardorf wrote:
> Hi
>
> I guess no answer is an answer .
>
Not necessarily. You could be asking the wrong question and or in the
wrong place.

> There are several ways to program for asynchronous serial interfaces,
> but there's only one way regarding to real time MIDI.
>

> When I programmed on Assembler in the 80ies I directly talked to the
> UART, and request CTS/RTS for every single byte.
>
> It's also possible not to use CTS/RTS for every single byte, but than
> you need to add headroom for the time. While it wouldn't be such a
> drama, if 1ms headroom would be 1ms, it's a drama because for such a
> long time a lot of IRQs are able to produce jitter, but a constant
> latency.
>
> I guess the MIDI coders for Linux did a bad job. I might be wrong, but
> as I said before, getting no answer is getting an answer .

I would hesitate to jump to this conclusion if I were you. I would also
rephrase this. Saying someone did a bad job but providing no real proof
is not usually a successful strategy in the open source world.

Also getting no answer may indicate a completely different problem.

> Hopefully I'm just paranoid and wrong .

I don't think paranoia is the right word.
>
> Cheers!
>
> Ralf
>
> -------- Forwarded Message --------
> From: Ralf Mardorf <ralf.mardorf@alice-dsl.net>
> To: Paul Davis <paul@linuxaudiosystems.com>
> Cc: James Morris <james@jwm-art.net>, Linux Audio Developers
> <linux-audio-dev@lists.linuxaudio.org>, 64studio-users
> <64studio-users@lists.64studio.com>
> Subject: Re: [LAD] basic MIDI note-on/note-off questions
> Date: Fri, 25 Jun 2010 15:51:13 +0200
>
> On Fri, 2010-06-25 at 15:36 +0200, Ralf Mardorf wrote:
>> On Fri, 2010-06-25 at 14:38 +0200, Ralf Mardorf wrote:
>>> On Fri, 2010-06-25 at 08:29 -0400, Paul Davis wrote:
>>>> On Fri, Jun 25, 2010 at 6:55 AM, James Morris <james@jwm-art.net> wrote:
>>>>> Hi,
>>>>>
>>>>> I keep getting surprised at some of the most basic problems I run
>>>>> into... This time, processing order.
>>>>
>>>> just remember that in "real" MIDI, nothing can be simultaneous. its a
>>>> serial protocol without timestamps. with traditional serial MIDI, the
>>>> time interval between bits and bytes is also fixed, creating a fixed
>>>> minimal interval between any two note on/off messages.
>>>
>>> In addition, the UART gives information about being ready to send. It's
>>> not fixed to e.g. 1ms. There's a register giving this information.
>>
>> Note, there's nothing fixed, the limitation is just for the max Baud
>> MIDI is able to do. Regarding to the term 'fixed' UART is for 'Universal
>> Asynchronous Receiver Transmitter', the important word is
>> 'Asynchronous'. We are talking about microseconds, taking care about the
>> CTS and RTS registers. Regarding to all that MIDI jitter, I wonder if
>> ALSA seq, might has to do with it. I don't know, perhaps there are
>> issues for USB specifications, but maybe there's something bad for this
>> 'timestamp' routs.
>>
>> *?*
>>
>> I programmed on Assembler directly using the UART and there never was
>> jitter.
>>
>> Could this be a reason for MIDI jitter using Linux or has it nothing to
>> do with it? Because, at the other hand there's no jitter internal the
>> studio in the box.
>>
>> *?*
>>
>> Ralf
>
> I can't remember, perhaps CTS and RTS are flags in one register and
> maybe they have other acronyms , anyway, this is the important stuff.
> Pedro Lopez-Cabanillas did post the technical specifications.
>
>
> _______________________________________________
> 64studio-users mailing list
> 64studio-users@lists.64studio.com
> http://lists.64studio.com/mailman/listinfo/64studio-users


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Old 06-25-2010, 09:07 PM
Gustin Johnson
 
Default basic MIDI note-on/note-off questions

On 10-06-25 02:13 PM, Ralf Mardorf wrote:
> On Fri, 2010-06-25 at 22:02 +0200, Ralf Mardorf wrote:
<snip>
> PS:
>
> I'm not sure, possible even it's needed to check CTS/RTS for the UART at
> all events (a long time ago since the 80ies), anyway, there is the
> possibility to control the UART with major priority by directly talking
> to it, or by using blabla seq talking to blabla serial interface handler
> written on C, were nobody knows what time consuming = IRQ allowing
> headroom it will produce. I suspect incompetent programming at least as
> one part for the hw MIDI jitter issue.

You suspect based on what?

> I guess MIDI on Linux isn't programmed for rt threads.
>
> BUT I don't know, nobody did reply.
>
You may need to ask a more precise question. You do have access to the
relevant source code.

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Old 06-25-2010, 09:31 PM
Ralf Mardorf
 
Default basic MIDI note-on/note-off questions

On Fri, 2010-06-25 at 15:05 -0600, Gustin Johnson wrote:
> On 10-06-25 02:02 PM, Ralf Mardorf wrote:
> > Hi
> >
> > I guess no answer is an answer .
> >
> Not necessarily. You could be asking the wrong question and or in the
> wrong place.
>
> > There are several ways to program for asynchronous serial interfaces,
> > but there's only one way regarding to real time MIDI.
> >
>
> > When I programmed on Assembler in the 80ies I directly talked to the
> > UART, and request CTS/RTS for every single byte.
> >
> > It's also possible not to use CTS/RTS for every single byte, but than
> > you need to add headroom for the time. While it wouldn't be such a
> > drama, if 1ms headroom would be 1ms, it's a drama because for such a
> > long time a lot of IRQs are able to produce jitter, but a constant
> > latency.
> >
> > I guess the MIDI coders for Linux did a bad job. I might be wrong, but
> > as I said before, getting no answer is getting an answer .
>
> I would hesitate to jump to this conclusion if I were you. I would also
> rephrase this. Saying someone did a bad job but providing no real proof
> is not usually a successful strategy in the open source world.
>
> Also getting no answer may indicate a completely different problem.
>
> > Hopefully I'm just paranoid and wrong .
>
> I don't think paranoia is the right word.
> >
> > Cheers!
> >
> > Ralf
> >
> > -------- Forwarded Message --------
> > From: Ralf Mardorf <ralf.mardorf@alice-dsl.net>
> > To: Paul Davis <paul@linuxaudiosystems.com>
> > Cc: James Morris <james@jwm-art.net>, Linux Audio Developers
> > <linux-audio-dev@lists.linuxaudio.org>, 64studio-users
> > <64studio-users@lists.64studio.com>
> > Subject: Re: [LAD] basic MIDI note-on/note-off questions
> > Date: Fri, 25 Jun 2010 15:51:13 +0200
> >
> > On Fri, 2010-06-25 at 15:36 +0200, Ralf Mardorf wrote:
> >> On Fri, 2010-06-25 at 14:38 +0200, Ralf Mardorf wrote:
> >>> On Fri, 2010-06-25 at 08:29 -0400, Paul Davis wrote:
> >>>> On Fri, Jun 25, 2010 at 6:55 AM, James Morris <james@jwm-art.net> wrote:
> >>>>> Hi,
> >>>>>
> >>>>> I keep getting surprised at some of the most basic problems I run
> >>>>> into... This time, processing order.
> >>>>
> >>>> just remember that in "real" MIDI, nothing can be simultaneous. its a
> >>>> serial protocol without timestamps. with traditional serial MIDI, the
> >>>> time interval between bits and bytes is also fixed, creating a fixed
> >>>> minimal interval between any two note on/off messages.
> >>>
> >>> In addition, the UART gives information about being ready to send. It's
> >>> not fixed to e.g. 1ms. There's a register giving this information.
> >>
> >> Note, there's nothing fixed, the limitation is just for the max Baud
> >> MIDI is able to do. Regarding to the term 'fixed' UART is for 'Universal
> >> Asynchronous Receiver Transmitter', the important word is
> >> 'Asynchronous'. We are talking about microseconds, taking care about the
> >> CTS and RTS registers. Regarding to all that MIDI jitter, I wonder if
> >> ALSA seq, might has to do with it. I don't know, perhaps there are
> >> issues for USB specifications, but maybe there's something bad for this
> >> 'timestamp' routs.
> >>
> >> *?*
> >>
> >> I programmed on Assembler directly using the UART and there never was
> >> jitter.
> >>
> >> Could this be a reason for MIDI jitter using Linux or has it nothing to
> >> do with it? Because, at the other hand there's no jitter internal the
> >> studio in the box.
> >>
> >> *?*
> >>
> >> Ralf
> >
> > I can't remember, perhaps CTS and RTS are flags in one register and
> > maybe they have other acronyms , anyway, this is the important stuff.
> > Pedro Lopez-Cabanillas did post the technical specifications.
> >
> >
> > _______________________________________________
> > 64studio-users mailing list
> > 64studio-users@lists.64studio.com
> > http://lists.64studio.com/mailman/listinfo/64studio-users
>
>
> _______________________________________________
> 64studio-users mailing list
> 64studio-users@lists.64studio.com
> http://lists.64studio.com/mailman/listinfo/64studio-users

The question is very simple. The UART (used by MPU etc.) in the 80ies
very seldom the ACIA too, can be used directly on Assembler or by
grotesque detours and C must not be the bad, if one knows what he does
on C. At least I wonder about the statements from Paul Davis, the Guru
for RT Linux. It is completely nonsense what he has written, that there
anything regarding to the time is fixed for an asynchronous serial
interface. If you take care about the CTS/RTS there's nothing fixed. He
doesn't know what he was talking about. I do know what I'm talking
about, hence it was my job and in addition I did what today is called
FLOSS myself a long time before there was Linux rt.

The big OZ Mr. Davis did wrote nonsense, idiotic stuff, he complete has
no knowledge about RT MIDI regarding to software + hardware.

That's it!

Cheers!

Ralf

PS: Is MIDI for Linux an RT thread? Is it? Or could e.g. the graphics
interrupt the movement from ALSA seq to the MIDI interface?

I've got no knowledge about Linux, but I do have knowledge about
hardware + software regarding to music and especially regarding to MIDI.

What's bad with my question?

Jitterless MIDI does mean you have to program for MIDI rt too, this
means you request CTS/RTS and do write one byte directly to the MIDI
interface. If it should be done on Linux in any other way, than it's
incompetent programed.

ALSA seq might not be the bad, but how is it handled to talk to the
UART? Is runtime lib a talking to runtime lib b? If so the coders did a
bad job. This isn't the way you can handle an asynchronous serial
interface for real time.

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Old 06-25-2010, 09:40 PM
Ralf Mardorf
 
Default basic MIDI note-on/note-off questions

On Fri, 2010-06-25 at 15:07 -0600, Gustin Johnson wrote:
> On 10-06-25 02:13 PM, Ralf Mardorf wrote:
> > On Fri, 2010-06-25 at 22:02 +0200, Ralf Mardorf wrote:
> <snip>
> > PS:
> >
> > I'm not sure, possible even it's needed to check CTS/RTS for the UART at
> > all events (a long time ago since the 80ies), anyway, there is the
> > possibility to control the UART with major priority by directly talking
> > to it, or by using blabla seq talking to blabla serial interface handler
> > written on C, were nobody knows what time consuming = IRQ allowing
> > headroom it will produce. I suspect incompetent programming at least as
> > one part for the hw MIDI jitter issue.
>
> You suspect based on what?
>
> > I guess MIDI on Linux isn't programmed for rt threads.
> >
> > BUT I don't know, nobody did reply.
> >
> You may need to ask a more precise question. You do have access to the
> relevant source code.

I did answer to your mail before, if this isn't precise enough, well, I
could go deeper to the stuff. What exactly is needed for a 'Linux
community correct question'? Since the 80ies I've forgotten a lot, but
this isn't an issue, I still have all those folders (not files, real one
for paper) at hand.

I did program + solder, I guess for MIDI on Linux the coders have a lot
of knowledge regarding to program by theory, but they miss to optimice
it to the oldish hardware (no soldering anymore). Not the MIDI hardware
or the technical specifications are bad. Don't believe me, just compare
a sequencer from the 80ies with a Linux one.

Truth seems to be a problem for Linux rt .

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Old 06-25-2010, 10:07 PM
Ralf Mardorf
 
Default basic MIDI note-on/note-off questions

On Fri, 2010-06-25 at 15:05 -0600, Gustin Johnson wrote:
[snip]

The CPU for the C64, 0.985248 MHz PAL and 1.022727 MHz NTSC. You even
don't need to do zeropage programming for MIDI rt, for other usage you
need to do zeropage programming to be fast enough. The 6502 and 6510
were single core processors with less, but 64-bit.

Don't try to teach me to ask the correct questions, as long you aren't
able to teach me were I'm mistaken . Prejudice against my person,
won't move away the facts.

This doesn't mean that my conjectures are correct. I just asked and
anybody who put my conjectures right is welcome.

Brainstorming should become part of rt MIDI for Linux.

I don't say that I'm right, I just say that e.g. Paul Davis is mistaken.

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Old 06-25-2010, 10:18 PM
Gustin Johnson
 
Default basic MIDI note-on/note-off questions

On 10-06-25 03:31 PM, Ralf Mardorf wrote:
> On Fri, 2010-06-25 at 15:05 -0600, Gustin Johnson wrote:
>> On 10-06-25 02:02 PM, Ralf Mardorf wrote:
>>> Hi
>>>
>>> I guess no answer is an answer .
>>>
>> Not necessarily. You could be asking the wrong question and or in the
>> wrong place.
>>
>>> There are several ways to program for asynchronous serial interfaces,
>>> but there's only one way regarding to real time MIDI.
>>>
>>
>>> When I programmed on Assembler in the 80ies I directly talked to the
>>> UART, and request CTS/RTS for every single byte.
>>>
>>> It's also possible not to use CTS/RTS for every single byte, but than
>>> you need to add headroom for the time. While it wouldn't be such a
>>> drama, if 1ms headroom would be 1ms, it's a drama because for such a
>>> long time a lot of IRQs are able to produce jitter, but a constant
>>> latency.
>>>
>>> I guess the MIDI coders for Linux did a bad job. I might be wrong, but
>>> as I said before, getting no answer is getting an answer .
>>
>> I would hesitate to jump to this conclusion if I were you. I would also
>> rephrase this. Saying someone did a bad job but providing no real proof
>> is not usually a successful strategy in the open source world.
>>
>> Also getting no answer may indicate a completely different problem.
>>
>>> Hopefully I'm just paranoid and wrong .
>>
>> I don't think paranoia is the right word.
<snip>
>
> The question is very simple. The UART (used by MPU etc.) in the 80ies
> very seldom the ACIA too, can be used directly on Assembler or by
> grotesque detours and C must not be the bad, if one knows what he does
> on C. At least I wonder about the statements from Paul Davis, the Guru
> for RT Linux. It is completely nonsense what he has written, that there
> anything regarding to the time is fixed for an asynchronous serial
> interface. If you take care about the CTS/RTS there's nothing fixed. He
> doesn't know what he was talking about. I do know what I'm talking
> about, hence it was my job and in addition I did what today is called
> FLOSS myself a long time before there was Linux rt.

Did the hardware you use in any way resemble modern hardware? Personal
attacks are probably not the best way to get the help. Just a little a
suggestion.
>
> The big OZ Mr. Davis did wrote nonsense, idiotic stuff, he complete has
> no knowledge about RT MIDI regarding to software + hardware.
>
<snip>
> PS: Is MIDI for Linux an RT thread? Is it? Or could e.g. the graphics
> interrupt the movement from ALSA seq to the MIDI interface?
>
I don't know, but I bet the answer is in the source code.

> I've got no knowledge about Linux, but I do have knowledge about
> hardware + software regarding to music and especially regarding to MIDI.

>
> What's bad with my question?

I am not sure to which vague question you are referring.
>
> Jitterless MIDI does mean you have to program for MIDI rt too, this
> means you request CTS/RTS and do write one byte directly to the MIDI
> interface. If it should be done on Linux in any other way, than it's
> incompetent programed.
>
So, how was it done? You have oversimplified the equation.

> ALSA seq might not be the bad, but how is it handled to talk to the
> UART? Is runtime lib a talking to runtime lib b? If so the coders did a
> bad job. This isn't the way you can handle an asynchronous serial
> interface for real time.
>
You know, I am not sure how it was done. I am sure the answer is there
in the source code if you want to find out.

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