its the usb thats the problem not the midi
usb to midi interfaces are the ones that mess up midi timing
my hardware sequencers mpc60 and the quasimidi cyber6 dont suffer like certain usb to midi devices
and its also proven that not all usb to midi devices are equal as proven by some not sending sysex properly
----- Original Message -----
From: Lee Borrell
To: CZsynth@yahoogroups.com
Sent: Thursday, August 22, 2013 10:58 PM
Subject: Re: [CZsynth] Speed of sysex transfer
I am not quite clear on the mis-timing issue.
MIDI is asynchronous - each item has it's own master clock used to transfer the bits across the communicating line at 31.25 Kb - the timing of the MIDI clock is different than the clock used to clock the signals across the line,which is usually derived from a 1-4Mhz master clock.
The synchronization of any timing MIDI signal is thence due to the arrival of the timing message comprising the 8 bits of the System clock messages.
The MIDI system is capable of sending 31250 bits per second and the timing message is 8 bits - even if it was an entire midi message of 3x8bits (24 bits) this is still some 1300 messages during that time. Normal tempos of 120 or so BPM are hardly going to drift significantly are they?
I am open to "Bullshit calls" as I am just querying just how much any timing is likely to be out using 31.25 Kb?
________________________________
From: jammie <jammie.emma@...>
To: CZsynth@yahoogroups.com
Sent: Thursday, 22 August 2013, 21:40
Subject: Re: [CZsynth] Speed of sysex transfer
actually we have proven usb midi does drop notes out of time using an oscilloscope
and expersleepers software and usb timing is not rock solid as midi from the st
or expert sleepers audio to midi which is just great
http://www.expert-sleepers.co.uk/index_files/the-horrors-of-usb-midi-timing.php
heres a video showing you
defy away but thats just one example of many
----- Original Message -----
From: Loscha
To: CZsynth@yahoogroups.com
Sent: Thursday, August 22, 2013 1:37 PM
Subject: Re: [CZsynth] Speed of sysex transfer
You assert that MIDI over USB is sloppy.
This is the same as a schoolgirl saying toads gice you warts!!!
If you look at a MIDI USB over an oscilloscope, as I have, you'll see
it is just fine. I do not have any pictures to document this, sadly --
and my scope is not currently set up.
I defy you to produce factual evidence to the contrary, however!
MiDI is not ideal for tight timing.
If you look at, say, laying a 4 down kick drum on a track, unless that
tempo you are using is an integer divisor of 31250, it's going to flop
around and not be in time.
Period.
On 8/22/13, jammie <jammie.emma@...> wrote:
> you could fit a lan midi port on the cz this is attached to the pre opto
> isolaters of the uart
>
> then you can use midi over lan
>
> but the midi protocol is still 31.25kb period thats the standard set
>
> but the problem lies with the usb and windows changing it from win98
>
> and since then midi timing has been sloppy
>
> now a parallel interface is much better and timing is much better
>
> so a opcode x64 which i still use and has xp 32 and 64bit drivers
>
> and i have never had any problems with sysex
>
> but i still use sound diver and changeit which is a great sysex sender and
> has a section for slowing down packets
> ----- Original Message -----
> From: Lee Borrell
> To: CZsynth@yahoogroups.com
> Sent: Thursday, August 22, 2013 12:47 PM
> Subject: Re: [CZsynth] Speed of sysex transfer
>
>
>
> I think if you talking about USB to USB transfer - or Firewire then you
> may have a point ,but as soon as any interface hits a MIDI DIN plug it HAS
> to be 31.25 Kb - this is the MIDI standard. No commercial interface with DIN
> plugs on it is going to do better than that baud rate,or face the equipment
> not getting the signal. In the case of pre-USB vintage machines,there is no
> way to go faster than 31.25kB.
>
> ________________________________
> From: fulfil_objective <robot@...>
> To: CZsynth@yahoogroups.com
> Sent: Thursday, 22 August 2013, 7:21
> Subject: [CZsynth] Speed of sysex transfer
>
>
>
> Hi Steve,
>
> I think you are too focused on these vintage numbers like 31250 bps and
> 115200 bps. Transferring sysex by USB and MIDI are not limited to these old
> numbers. USB enables speeds that are hundreds or thousands of times faster
> than these numbers. In fact, greatly higher speeds are touted as one of the
> benefits of a USB MIDI device (along with multiple streams).
>
> High speed sysex transfer is both desired and encouraged, for example, in
> the case of sending sound data to a sampler. If you wanted to send 128
> megabytes of sounds to your sampler, and if you were restricted to 31250
> bps, it would take 9.5 hours to send the sounds. USB MIDI devices enable
> higher speeds, and that speed is encouraged.
>
> 31250 bps is the speed of an old dialup modem (actual throughput) on a
> good day. If you tested at 115200 bps, that is merely 3.7 times faster than
> 31250 bps. Still very slow by today's standards.
>
> USB 2.0 has a max throughput of something like 35 MB/s. But lets be
> generous and say that in the real world, you can only get your USB 2.0 to 20
> MB/s. That speed, 20 MB/s, works out to 160,000,000 bps, which is 5,120
> times faster than 31250 bps.
>
> So yes, I think a capable modern computer with a good USB system can send
> sysex out faster than the CZ can deal with it. And it's not necessarily tied
> to CPU speed of the computer either, more like the speed of the whole
> computer-USB system.
>
> You will probably find it enlightening to read the "Universal Serial Bus
> Device Class Definition for MIDI Devices", Release 1.0, Nov 1, 1999, which
> you cand download here:
>
> http://www.usb.org/developers/devclass_docs/midi10.pdf
>
> [Non-text portions of this message have been removed]
>
>
>
>
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> Checked by AVG - www.avg.com
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>
>
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>
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Re: [CZsynth] Speed of sysex transfer
2013-08-22 by jammie