Do you use/need more than one MIDI input?

Somewhere to chat about MIDI music creation, sequencers and related hardware

Moderators: Mug UK, lotek_style, Moderator Team

User avatar
Foxie
Captain Atari
Captain Atari
Posts: 354
Joined: Wed Feb 03, 2016 7:12 pm

Do you use/need more than one MIDI input?

Postby Foxie » Tue Feb 27, 2018 7:02 pm

If you have SMP24/II, Midi3, Midex, Unitor or a Mac interface on your Atari, do you use and rely on the MIDI inputs on it?

Since I'm working on designing a new MIDI port expander for the Atari, I wondered whether to include extra MIDI inputs on the device in addition to the eight outputs.

Some potential advantages of including the MIDI inputs:

1: Obviously, you can connect multiple MIDI sources to your Atari without a MIDI merger (although I'll only include a couple of inputs, most likely - unless there's a real demand for more).

2: The additional inputs will be low latency and low jitter. If you use a MIDI merge box to feed everything into the Atari's single input, they usually add 0.3ms - 1ms extra latency. If you use a device like Midex or Unitor, they have a jitter on their MIDI inputs of around 0.3ms. Whether you can tell the difference in Cubase (which has an additional jitter and latency of its own) I don't know - but Midex/Unitor are not as good as theoretically possible.

3: It provides a way of getting MIDI time code into the Atari without the overhead of merging it with your keyboard's output. Merging live keyboard playing with MTC results in a 0.6ms jitter on occasional notes. Not as bad as the Midex/Unitor jitter because it's only occasional, not every note. Though of course, you could use a Midex or a Unitor with its LTC SMPTE input for sync instead of MTC.

4: The device could also be used to add MIDI inputs to systems that don't have any MIDI inputs, like the Amiga. Though not strictly necessary - you can add a MIDI input to the Amiga's modem port inexpensively.

And some disadvantages of including the MIDI inputs:

1: Larger PCB, slightly more costly hardware. Also longer development time. More potential for bugs.

2: Initially, the MIDI inputs won't work in Cubase anyway. I need to learn more about how Cubase drivers work in order to implement the MIDI inputs. While I hope to succeed in this, I can't guarantee anything because there's zero documentation on MROS drivers. I hope to eventually make some music software of my own - in which case the MIDI inputs will of course work there. The MIDI inputs can also be used for a MIDI thru function, by flipping a thru switch which routes the input through to all eight outputs (without needing the computer to be turned on).

3: If I design my own music software, it's more difficult to implement multiple MIDI inputs (but not too difficult). If most musicians are only using the Atari MIDI input, that's all I need to implement.

4: For a while I've been pondering the design of a zero-latency MIDI merger device. As far as I can see, this is very possible to do. So by making such a device available, you won't need multiple inputs. You can just merge everything into the Atari's MIDI input with no latency penalty. There are some advantages to this approach, since it will work with all software - including synthesizer editors which are often hard-coded to use only the Atari's MIDI input.

User avatar
Saturnin51
Captain Atari
Captain Atari
Posts: 158
Joined: Thu Jan 14, 2010 7:59 pm
Location: THIAIS - FRANCE

Re: Do you use/need more than one MIDI input?

Postby Saturnin51 » Tue Feb 27, 2018 7:54 pm

I have a SM24. It is plugged to the Falcon by the printer port.
I plug on the SMP24 two devices on the MIDI IN (keybord and drum) and three expanders on MIDI OUT.
I use the Falcon MIDI ports when I use an editor with an expander, IN and OUT/THRU.
Falcon 030-14 Mo - FDI Steinberg -Soundpool Analog 8 - SMP24 - Cubase Audio Falcon 2.06 dongle - SC55 - SG64 - Yamaha CBX-T3

User avatar
Atari74user
Captain Atari
Captain Atari
Posts: 297
Joined: Mon Aug 10, 2009 8:00 pm

Re: Do you use/need more than one MIDI input?

Postby Atari74user » Tue Feb 27, 2018 9:03 pm

Indeed, personally I use the MIDI Ins on my SMPII, Midex and Unitor.

I do use a MIDI merger too. I have never had too many problems with latency, but again, personally I am not going to sit there and measure it, I'll just go by ear. Different when you are designing of course, you want to factor this stuff in and be meticulous. If I do experience issues, then I just mix down onto multitrack and sync via MTC to take any MIDI strain off.
Atari Falcon 14mb, 68882, Dual 8gb CF, Steinberg FDI & Analog 8
Atari Jaguar, Rotary controller, Skunkboard & Cat Box
Atari 520STFM 4mb, TOS 2.06 switcher, OverScan, GigaFile, PARCP-USB, Unicorn-USB, System Solutions MiniS HD, SyQuest drives, ICD Link II, PhatBoy MIDI Controller, Philip Rees 5M MIDI merge box, SoundPool MO4, Steinberg MIDEX, SMP II, Emagic Log 3, C-Lab Unitor 2, Combiner & Export expanders

ranix
Atari maniac
Atari maniac
Posts: 89
Joined: Sun Jan 14, 2018 8:01 pm

Re: Do you use/need more than one MIDI input?

Postby ranix » Wed Feb 28, 2018 4:56 am

I also do use the midi inputs on my Unitor. I have a keyboard near the Atari for using for step input connected to the unitor and a midi controller for recording live play connected directly to the Atari. This is pretty useful. I could use a merge box to combine the inputs though that's not a big deal

Miguel
Obsessive compulsive Atari behavior
Obsessive compulsive Atari behavior
Posts: 134
Joined: Mon Sep 21, 2015 2:59 pm

Re: Do you use/need more than one MIDI input?

Postby Miguel » Wed Feb 28, 2018 1:59 pm

I wouldn't say I rely on the additional MIDI inputs but I do use them on occasion for MIDI dumps and controlling stuff that isn't timing critical.

plexicube
Retro freak
Retro freak
Posts: 14
Joined: Fri Oct 28, 2016 2:19 am

Re: Do you use/need more than one MIDI input?

Postby plexicube » Mon Mar 05, 2018 2:27 am

I use one input to sync a 24 track recorder with MTC and one for actual musical input.

User avatar
charles
10 GOTO 10
10 GOTO 10
Posts: 2372
Joined: Tue Aug 17, 2004 12:11 am
Location: ont. Canada
Contact:

Re: Do you use/need more than one MIDI input?

Postby charles » Mon Mar 05, 2018 4:45 am

often yes ,,,,however merger works
atari is my lifestyle,not a hobby.
HOLD ON ! ! !,
Im printing unreadable characters ...!

User avatar
Foxie
Captain Atari
Captain Atari
Posts: 354
Joined: Wed Feb 03, 2016 7:12 pm

Re: Do you use/need more than one MIDI input?

Postby Foxie » Tue Mar 06, 2018 5:57 pm

It appears there is demand for additional MIDI inputs? Or could it be that everyone who wants additional MIDI inputs already has the necessary hardware?

My main concern at this point is figuring out how to write a Cubase driver to take advantage of the additional inputs. It seems pointless to include them if I can't get them working in Cubase. I don't imagine many people wanting to switch to any music software I create in preference to Cubase!

Implementing inputs does add some additional complexity to the circuit design in surprising ways. The firmware also becomes considerably more complicated. So complicated in fact, that I'd need to write some additional code to ensure the firmware can be flash upgraded in case I make a mistake!

The output-only firmware by comparison is very simple, to the point where I'm reasonably confident it won't need any kind of flash upgrade procedure.

Another thing I'm looking into is Firebee support. Obviously at the moment, it's moot since Cubase won't run on the Firebee. In the future, it might. Or, I might have made some music software of my own which works on the Firebee. I haven't yet been able to determine whether it's even possible to get MIDI input through the Firebee's printer port - it might be designed in a way that makes it impossible. Another problem stems from the fact there is a small but significant design oversight in the Firebee. If the MIDI expander is switched on before the Firebee is switched on - or the Firebee is switched off before the expander is switched off - the Firebee could become damaged. This can also happen with a normal printer. I could implement a work-around by dropping the voltage on the printer port, although this will limit the maximum allowable cable length. I'm tending to think it would be better for Firebee owners to fit a protection device in series with the printer port, which will make the Firebee completely safe to use with MIDI expanders and ordinary printers. Such a device is trivial to make with a few zener diodes.

User avatar
charles
10 GOTO 10
10 GOTO 10
Posts: 2372
Joined: Tue Aug 17, 2004 12:11 am
Location: ont. Canada
Contact:

Re: Do you use/need more than one MIDI input?

Postby charles » Wed Mar 07, 2018 12:13 am

have you any programs written for the Atari ever?
atari is my lifestyle,not a hobby.
HOLD ON ! ! !,
Im printing unreadable characters ...!

User avatar
Foxie
Captain Atari
Captain Atari
Posts: 354
Joined: Wed Feb 03, 2016 7:12 pm

Re: Do you use/need more than one MIDI input?

Postby Foxie » Wed Mar 07, 2018 1:26 am

charles wrote:have you any programs written for the Atari ever?


I used to do a fair bit back in the 90s, but nothing finished enough to publish. Most of the things I've written in the last few years have been libraries and frameworks for making other projects rather than complete programs.

User avatar
charles
10 GOTO 10
10 GOTO 10
Posts: 2372
Joined: Tue Aug 17, 2004 12:11 am
Location: ont. Canada
Contact:

Re: Do you use/need more than one MIDI input?

Postby charles » Wed Mar 07, 2018 3:04 am

love to know more
atari is my lifestyle,not a hobby.
HOLD ON ! ! !,
Im printing unreadable characters ...!

User avatar
tyk
Atari nerd
Atari nerd
Posts: 44
Joined: Fri Sep 23, 2011 5:55 pm

Re: Do you use/need more than one MIDI input?

Postby tyk » Thu Mar 08, 2018 9:04 pm

Foxie wrote:Some potential advantages of including the MIDI inputs:


5. Complex routings between multitimbre MIDI-devices. I have dreamed about 3 separate midi inputs and outputs. There is some mixer like controllers that put sliders to every channel, so there isn't left any channel to keyboards. And there is some rack-synthesizer that use heavy sysex that they really need own midi-cables. So if somebody make hardware, I promise make (maybe ugly and hard to use) routing program.

User avatar
Atari74user
Captain Atari
Captain Atari
Posts: 297
Joined: Mon Aug 10, 2009 8:00 pm

Re: Do you use/need more than one MIDI input?

Postby Atari74user » Thu Mar 08, 2018 10:45 pm

MIDI ins would be very pleasing for me, if i were to be greedy!
:angel:
Atari Falcon 14mb, 68882, Dual 8gb CF, Steinberg FDI & Analog 8
Atari Jaguar, Rotary controller, Skunkboard & Cat Box
Atari 520STFM 4mb, TOS 2.06 switcher, OverScan, GigaFile, PARCP-USB, Unicorn-USB, System Solutions MiniS HD, SyQuest drives, ICD Link II, PhatBoy MIDI Controller, Philip Rees 5M MIDI merge box, SoundPool MO4, Steinberg MIDEX, SMP II, Emagic Log 3, C-Lab Unitor 2, Combiner & Export expanders

User avatar
charles
10 GOTO 10
10 GOTO 10
Posts: 2372
Joined: Tue Aug 17, 2004 12:11 am
Location: ont. Canada
Contact:

Re: Do you use/need more than one MIDI input?

Postby charles » Fri Mar 09, 2018 1:09 am

im off topic , but do u and i have some shared midi equipment...?
im in (and have been for about 6 years) the process of
writing sysex editors/librarians for the equipment I own

I don't mind sharing my programs as long as I get something in return ...
atari is my lifestyle,not a hobby.
HOLD ON ! ! !,
Im printing unreadable characters ...!

JoeAtari
Atari maniac
Atari maniac
Posts: 93
Joined: Wed Dec 26, 2012 8:20 pm
Location: Chino Valley, Arizona, USA
Contact:

Re: Do you use/need more than one MIDI input?

Postby JoeAtari » Fri Mar 09, 2018 6:10 pm

With my setup I only use the Midi in on the Falcon for my dedicated keyboard controller (no sounds). I have three different sound sources, and I'm currently using the Falcon Midi out plus two outs on my SMP II. I would think that if you needed more inputs you could just use a merge box? I think it is very cool that you are working on this!
JoeAtari
FalconProductions - Chino Valley, Arizona, USA
http://www.falconproductions.us
http://www.facebook.com/AtariSTBook

User avatar
Foxie
Captain Atari
Captain Atari
Posts: 354
Joined: Wed Feb 03, 2016 7:12 pm

Re: Do you use/need more than one MIDI input?

Postby Foxie » Mon Mar 12, 2018 7:32 pm

charles wrote:im off topic , but do u and i have some shared midi equipment...?
im in (and have been for about 6 years) the process of
writing sysex editors/librarians for the equipment I own


What sort of equipment have you written editors for? My synths are mostly older digital synths, although I yearn for a fully working and calibrated Prophet 5. The Prophet 5 is very slow though, 4ms latency and a massive 8ms jitter! If I ever got one, I'd be tempted to retrofit a faster CPU.

Do your synth editors work alongside a sequencer somehow? I know MROS can allow for that, but it doesn't seem to be used very often. Desk accessories seem like a good way to do synth editing. If I make some sequencer software, I'm thinking I might re-route the XBIOS MIDI output calls into the routing/merging core of the sequencer. That way, you could then use a desk accessory synth editor and route it through to any MIDI output. Otherwise you tend to need a MIDI patchbay to send the Atari's MIDI out to the correct synth.

tyk wrote:5. Complex routings between multitimbre MIDI-devices. I have dreamed about 3 separate midi inputs and outputs. There is some mixer like controllers that put sliders to every channel, so there isn't left any channel to keyboards. And there is some rack-synthesizer that use heavy sysex that they really need own midi-cables. So if somebody make hardware, I promise make (maybe ugly and hard to use) routing program.


This sounds interesting, do you need information about programming MIDI hardware? I know how to program the Soundpool MO4, Friend Chip MM1, C-Lab Export, and the Macman. I've got some information on the Midex and Unitor, although I need to do more work reverse-engineering them. The Log3 and the SMP24/II remain a bit of a mystery to me.

I was planning to simply merge all MIDI inputs together in my sequencer. All 16 channels remain independent, but not the individual inputs. However, the hardware I'm designing will probably keep each of the MIDI inputs independent - so you could do some complex routing if programming it directly.


Atari74user wrote:MIDI ins would be very pleasing for me, if i were to be greedy!
:angel:


If I do include MIDI inputs, then how many inputs? I was thinking of two, because that requires little extra hardware. I could increase that to six by using an additional MCU. It seems a bit silly to go to that effort if I can't figure out how to support the inputs in Cubase!

One option I have considered is to have a mode which turns it into a merge box. The six inputs would be merged, and sent out the eighth MIDI output. You could then plug that output into the Atari's MIDI input - giving you six MIDI inputs without the extra expense of a merge box.

User avatar
tyk
Atari nerd
Atari nerd
Posts: 44
Joined: Fri Sep 23, 2011 5:55 pm

Re: Do you use/need more than one MIDI input?

Postby tyk » Mon Mar 12, 2018 8:37 pm

Foxie wrote:This sounds interesting, do you need information about programming MIDI hardware? I know how to program the Soundpool MO4, Friend Chip MM1, C-Lab Export, and the Macman. I've got some information on the Midex and Unitor, although I need to do more work reverse-engineering them. The Log3 and the SMP24/II remain a bit of a mystery to me.


Right now I need more time for programming :) After that I might need more information about Macman.
Steinberg SMP24 is made for Steinberg by Waldorf, so do somebody knows people from there?

Foxie wrote:I was planning to simply merge all MIDI inputs together in my sequencer. All 16 channels remain independent, but not the individual inputs. However, the hardware I'm designing will probably keep each of the MIDI inputs independent - so you could do some complex routing if programming it directly.


Please keep inputs independent, because it gives more freedom even for merge or not.

User avatar
Atari74user
Captain Atari
Captain Atari
Posts: 297
Joined: Mon Aug 10, 2009 8:00 pm

Re: Do you use/need more than one MIDI input?

Postby Atari74user » Mon Mar 12, 2018 10:13 pm

If I do include MIDI inputs, then how many inputs? I was thinking of two, because that requires little extra hardware. I could increase that to six by using an additional MCU. It seems a bit silly to go to that effort if I can't figure out how to support the inputs in Cubase!

One option I have considered is to have a mode which turns it into a merge box. The six inputs would be merged, and sent out the eighth MIDI output. You could then plug that output into the Atari's MIDI input - giving you six MIDI inputs without the extra expense of a merge box.


Awesome, six would be amazing, but like your initial thought, I was hoping for two, much like the SMP24 / II, that would seal it for me. :D
Atari Falcon 14mb, 68882, Dual 8gb CF, Steinberg FDI & Analog 8
Atari Jaguar, Rotary controller, Skunkboard & Cat Box
Atari 520STFM 4mb, TOS 2.06 switcher, OverScan, GigaFile, PARCP-USB, Unicorn-USB, System Solutions MiniS HD, SyQuest drives, ICD Link II, PhatBoy MIDI Controller, Philip Rees 5M MIDI merge box, SoundPool MO4, Steinberg MIDEX, SMP II, Emagic Log 3, C-Lab Unitor 2, Combiner & Export expanders

User avatar
charles
10 GOTO 10
10 GOTO 10
Posts: 2372
Joined: Tue Aug 17, 2004 12:11 am
Location: ont. Canada
Contact:

Re: Do you use/need more than one MIDI input?

Postby charles » Wed Mar 14, 2018 10:53 am

didn't the hotz system isolate and use multi midi ports...
same with the smpte box multi plexer/ edit-smpte track ?
atari is my lifestyle,not a hobby.
HOLD ON ! ! !,
Im printing unreadable characters ...!

MIDIbro
Retro freak
Retro freak
Posts: 16
Joined: Thu Nov 16, 2017 7:23 am

Re: Do you use/need more than one MIDI input?

Postby MIDIbro » Wed Mar 14, 2018 11:33 am

I used to have a midiex, used the multiple ins and outs a few times when using it as a main sequencer, but modern thru boxes are really good and i have never noticed a decrease in performance using thru boxes instead,.
Do not own a ST right now

User avatar
charles
10 GOTO 10
10 GOTO 10
Posts: 2372
Joined: Tue Aug 17, 2004 12:11 am
Location: ont. Canada
Contact:

Re: Do you use/need more than one MIDI input?

Postby charles » Wed Mar 14, 2018 9:52 pm

im sorta loosing my patience foxie , any neat code I can tinker with ?
atari is my lifestyle,not a hobby.
HOLD ON ! ! !,
Im printing unreadable characters ...!

User avatar
Foxie
Captain Atari
Captain Atari
Posts: 354
Joined: Wed Feb 03, 2016 7:12 pm

Re: Do you use/need more than one MIDI input?

Postby Foxie » Thu Mar 15, 2018 5:59 pm

charles wrote:im sorta loosing my patience foxie , any neat code I can tinker with ?


If you want to try and help figure out how MROS works, I've completely disassembled and documented the driver for the MM1:

https://pastebin.com/uRK1ms8w

At first brush it appears quite simple. There are some strange aspects to it. The next step is disassembling a few more drivers to gather more information that way. I also plan to write a bare-bones MROS driver for testing. If you need to know about how certain aspects work, I can answer specific questions.

Some good news already - since disassembling the driver, I now have enough information to support an arbitrary number of MIDI outs. I don't know if anyone really needs more than 8 independent outs, but considering the hardware is so cheap I may as well have a few more. Personally I would find 8 outputs a little limiting if it were my only MIDI expander, but of course you can add devices like Midex too. I've got enough free pins on the MCU to implement 10-12 outputs for sure. I could even go to 15 - but let's be honest, that's pretty crazy. I'd be worried about the size of the PCB with all those sockets. The good thing about modern MCUs is that they're fast enough to do MIDI output in the firmware. The only hardware you need is a few resistors and a socket.

I still don't know how to implement MIDI inputs. Disassembling the MIDI3 driver will help, I hope.

I've also posted this survey: viewtopic.php?f=111&t=33384

User avatar
charles
10 GOTO 10
10 GOTO 10
Posts: 2372
Joined: Tue Aug 17, 2004 12:11 am
Location: ont. Canada
Contact:

Re: Do you use/need more than one MIDI input?

Postby charles » Thu Mar 15, 2018 11:17 pm

; Pass dev_struct into MROS IOM. Opcode $14 (undocumented).
pea dev_struct(pc)
move.w #$14,-(a7)
trap #10
addq.l #6,a7

; Return with pointer to vars in a5.
lea vars(pc),a5
rts


opcode 14

is xbios 14

this is fetching the address of the midi buffer ???????

if theres data placed into the midi buffer and you change the interupt priority level
it will out put whats in the buffer.

but by using 512 byte blocks I feel this is using only 4 configurations of 128 bytes
meaning it adds 4 individual outs? a midi buffer is circular and made of 128 bytes..

im horrible with 68k/asm.

they have installled different trap handlers within asm on some of the 68000's free lines
doubled the traps for the bios and xbios gemdos ////
but I can not provide any data to back up my beliefs as my coding has not risen to this level to test so ..
atari is my lifestyle,not a hobby.
HOLD ON ! ! !,
Im printing unreadable characters ...!

User avatar
Foxie
Captain Atari
Captain Atari
Posts: 354
Joined: Wed Feb 03, 2016 7:12 pm

Re: Do you use/need more than one MIDI input?

Postby Foxie » Fri Mar 16, 2018 12:33 am

charles wrote:; Pass dev_struct into MROS IOM. Opcode $14 (undocumented).
pea dev_struct(pc)
move.w #$14,-(a7)
trap #10
addq.l #6,a7

; Return with pointer to vars in a5.
lea vars(pc),a5
rts


opcode 14

is xbios 14


It's opcode $14 for trap #10, which as far as I can tell is the MROS IOM. MROS adds at least two traps of its own, to access the so-called MEM (trap #8) and IOM. It's a bit of a mystery how that interface works, but opcode $14 at least seems to be used to publish a driver.

There's also opcode $4 for MROS MEM. This one seems to return a structure containing useful information about MROS. The most important thing it returns is the mros_get_byte pointer.



charles wrote:this is fetching the address of the midi buffer ???????

if theres data placed into the midi buffer and you change the interupt priority level
it will out put whats in the buffer.

but by using 512 byte blocks I feel this is using only 4 configurations of 128 bytes
meaning it adds 4 individual outs? a midi buffer is circular and made of 128 bytes..


There appears to be a 512 byte buffer for each output. There's 8 outputs, so that's a total of 4096 bytes reserved for the buffers. I'm not sure why it's 512 bytes, other than it's probably large enough for any normal musical use. That's enough for 10 notes on each of the 16 channels without running status.

I'm not sure what happens if Cubase attempts to send so much data in one burst that the buffer fills up. I would hope Cubase stalls until the buffer empties. I wouldn't be terribly surprised if it just drops the data!

The pointers to the buffers are set up in the init_func_3 function. They're sent to MROS afterwards in main, using opcode $14. There's an array of eight port descriptor structures, each structure has the following format:

start_of_buf equ $24 ; Longword, pointer to start of data buffer.
end_of_buf equ $28 ; Longword, pointer to end of data buffer.
write_byte_ptr equ $90 ; Longword, pointer to write byte function.

write_byte_ptr gets called whenever MROS wants to write data to the driver. The strange thing is MROS seems to control the timing itself. I'm guessing it will always wait 0.3ms between calls.

The even stranger thing is that the driver doesn't use the data passed into write_byte_ptr. It only uses the port number. Instead, the data is read from MROS by calling mros_get_byte in the interrupt handler. I'm not sure if this is an MROS requirement or just a strange thing this particular driver does.


Return to “MIDI Software and Hardware”

Who is online

Users browsing this forum: No registered users and 2 guests