>4 trk sequencer.  "supersequencer&qu

With the  coming release of the new sequencer project.  First of all,  Iwould like to say… WOW !!  to TK.  

I intend to use this project for springboard for a 16 trk (more less?) sequencer.  Those of you with like minded aspirations, lets collaborate on this thread.

TK had to say this:

    16 track sequencer: everything is possible

BUT: only with some disadvantages, which

I don’t want to consider in my implementation.

With 16 tracks it wouldn’t be possible to store the whole  

pattern in RAM. The sequencer core has to read the  

pattern directly from EEPROM instead. This has no

timing disadvantages (remember that sending a

MIDI event takes 1 mS, an EEPROM value can be  

read within 10 uS…), but it makes realtime editing

via MIDI impossible. Most parts of the control surface

handler would have to be changed, so that only

the select track is buffered in RAM. Features like  

Morhphing wouldn’t be possible anymore, since this  

requires a second data set of the layer values.

The whole SysEx store structure would have to be

changed to a new format, it wouldn’t be possible

to store 128 patches in a single BankStick, but only

32 or so… a second JSynth GUI would be required to

take the changed data structure into account (note:

realtime editing with JSynth wouldn’t be possible  

anymore), and last but not least: a second documentation

would be required and somebody who answers the

questions to this different implementation.

Just take this into account…

And to repeat it for the guys who didn’t read my other  

postings regarding the reason, why I only

need a 4 track sequencer: I’m using it as creativity

tool. Once a nice sequence “works”, I record it with

Logic, and the MBSEQ is free for the next track.

Sooner or later I’ve to rearrange and mixdown the  

sequences anyhow, and for this an editor like Logic is  

much more efficient (yes, in this situation I really like  

to use a mouse).  

If you really want to record, play, arrange, mix a whole

song with a standalone device, then you have to program

something which has been done by Emagic or Steinberg

15 years ago - on the Atari ST (a second-hand Atari costs  

you less money and less effort)

Arumblack: for every CC’s you have to use a seperate

track. But see above, why more than this doesn’t make

sense. It is possible to chain multiple MBSEQs (synced

via MIDI clock), but it isn’t possible to control them from  

a single control surface (it would have to save all

editable parameters in RAM anyhow)

  So control surface handler would have to change as well as sysex format.    Would it be possible to use a “processing core” to handle the  ram buffer ?

No, the data transfer rate would be much slower than reading from an IIC EEPROM.

So long most pins are free, you could hook a 128k SRAM (like the 628128 ) to the core directly - here an example:

• data lines could be connected in parallel to the LCD port, 8 address lines could be multiplexed with the data lines like known from 8051 designs (by using a 74HC573 latch)
• 8 additional address lines could be connected to J5
• the remaining address line to J7:RC
• the chip select to J7:SO
• the latch enable to J15:RS
• the R/W to J15:RW

You need to implement a (simple) read and write routine for RAM accesses (RAM_Write, RAM_Read) and put it into your application. The resulting access time should be about 2 microseconds (ca. 20 instructions) - fast enough for large data structures.

SRAMs can be buffered with a small 3V battery

Best Regards, Thorsten.

ok, not to pretend like i know what i’m talking about or anything but… I have been thinking on this today, and the possibility occured to me that we may have to start from scratch on this, ie the mios/core may simply not be powerful enough to do what we want. so, i think we need to decide exactly what we want it to do and how it should be implemented.Then asses wether it is possibl with the mios/core, or wether we need to use a more powerful microcontroller.

reflecting to what tk said about it may be easier and cheaper to get an old atari, well that may be true, but for me i am not concerned with ease or cost, This is what i hope to do(design music gear) for a living after graduating so that’s the motivation for me. plus i always seem to find something that annoys me with the stuff on the market out there. it remains to be seen if I/we can do it better.

but i cannot do this alone nor do i even currently posses the skills to get very far by myself. I am in no huge hurry. however my goals and timeframe may not be everyones so i guess i need opinions from anyone else wishing to join in. also please do not percieve this as me trying to run the show , i’m not. i’m just throwing out idea’s

yes sorry to ramble , I still think the place to start is a list of desired features. so i will start.

intended use: Live performance

16 tracks( and perhaps the ability to link2 or more units for more tracks)

step recording  and realtime recording

the ability to seamlessly go from playback into record(a feature i consider essential to live performance).

the ability to record note on off, velocity, and gate times, as well as cc’s(nrpn’s and sysex could be useful for some gear, but not essential,same for aftertouch)

“pattern” length of more than 1 measure(4 or better 8 measures?)

and some non essential features(but would be very useful to me)

Multiple midi outs(all mirroed) i have some synths that just don’t daisy chain well.

cv outs(not neccesary, perhaps an add on option)

that’s all i’ve got for now, sure there is more.

any other thoughts(feel free to tell me i am crazy as well)

Well,

Just for the record: Alesis MMT-8 runs 8 multichannel polyphonic tracks at 96ppqn resolution with 80c31 (dating back from '82, remember 80’s? ) (clocked  @ 11MHz and uses 12 clock cycles for most instructions!), (27c256) 32kB EPROM for code and 2*52256 32kB SRAMs for sequences.

I think that PIC 18F452 @ 40MHz easily outperforms that.

But, wait: “supersequencer”, with 16 MONOPHONIC tracks?! :o I really don’t see any advances in that concept over, well 4*MBSeq.. maybe for the drums.. (with those upcoming drum triggers )

Polyphonic tracks with “improved” ppqn resolution would be good aim?! And with that concept change it really needs much programming efford.

the ability to seamlessly go from playback into record

This is nice. With performance oriented sequencer I’d like to see also has ways to manipulate sequence live: Maybe assinging arpeggiator to one track and “bouncing” it to another, live recording mutes ect. something resembling DJ:ing with sequences.

Bye, Moebius

p.s. multiple midi out is easy to construct with hex inverter and few resistors.

ok, as i said i am no expert(yet).

and i knew i had forgot some things. yes i would want polyphonic tracks, though i personally wouldn’t need 16 polyphonic tracks. of course i forgot arps and midi delay., perhaps also some sort of midi crossfading?maybe midi lfo and envelopes? yes , the ppqn would need to be improved( i love machine gun drum rolls…) And what if you could grab a knob and search through sequences forward and reverse, like scratching a record?maybe you could link this to pitchbend also to get the pitching up/down effect also?

thanks for the input moebius!

Remind that the development and documentation of another hardware platform possibly requires more effort than you really want. During the last years I’ve read from a lot of people who planned something similar, but finally gave up due to unexpected problems. Don’t think that bigger microcontrollers can do the IO handling much faster than a PIC18F, and keep in mind that once you are using external memories, good system knowledge and soldering skills are required. The setup of a new platform and operating system requires good debugging tools, mostly they are not free available (maybe ARM7 would be a good solution, but a useful IDE costs at least 2000 EUR!)

So, from my experience I can give you following advice: if you plan to implement a much more powerfull, reproducible, standalone DIY sequencer with fast success and open possibilities, than use a cheap embedded PC board, use Embedded Linux as operating system, and use an external PIC18F452 (running under MIOS) to handle with the control elements (buttons, encoders, LCDs, LEDs, etc.) - connected via RS232 to the PC. The advantage of this approach would be, that everybody who owns a PC (from 386 upwards) can try your software, so there is no need for bying expensive hardware for the first tests.

Best Regards, Thorsten.

TK "So, from my experience I can give you following advice: if you plan to implement a much more powerfull, reproducible, standalone DIY sequencer with fast success and open possibilities, than use a cheap embedded PC board, use Embedded Linux as operating system, and use an external PIC18F452 (running under MIOS) to handle with the control elements (buttons, encoders, LCDs, LEDs, etc.) - connected via RS232 to the PC. "

You are very wise yes, the power of experience. Can you give me more info Embeded pc boards and embeded Linux? a few links maybe? I will do a search too, but right now i should really be doing homework… I think this would be a good plan.

Thank you so much.

The cheapest embedded PC is maybe the X-Box…

However, here some links:

http://test.elektroniknet.de/topics/embeddedsystems/produkte/2003/0002/index.htm

http://www.pcengines.ch

http://www.controlled.com

Best Regards, Thorsten.

Awesome! i checked out those links, and some others i found.

I guess my first step will be to learn LINUX. shouldn’t be a problem, i have acces to tons of books at school, and instructors and the students too, so that is where i will start.

plus finishing th MB stuff i’ve already started…i will try to source a cheap(like free) pc to begin work on the software, and work from there. hooray ! I’m sure this will be a lot of work , but i’ve got time, even if it takes the 4 years i am in school to finish…Thanks for the leads and advice Thorsten.

hey sil909…was doing some research on this, and found your post here

http://www.lionstracs.com/index.php?name=PNphpBB2&file=viewtopic&t=5

this thing looks like that ekosynth,and just as if not more expensive.that’s really more than i would be trying to do at the moment.but it does ahve some cool features.

yeah.. expensive is the word. but it got me thinking about using some dsp’s maybe from motorola and using linux.

 I think the hardware control portion is the easy part to do for a DIY project.  and Linux is free. I am not a "programmer per say.  but I think I an hak my way thru it.  there is an incredible amount of information out there regarding embedded systems.   90% of the time the big cost for music products ( controllers, VS synths etc. )  per unit would be the software.

Chips are fairly inexpensive in comparison.

The Midi box projects offer a wealth of value and posssibilities and inspires me everyday to new projects.

My Idea was to create a sequencer and control station for my Roland M-DC1.  Older dance expansion box.   I need 8 parts or sequencer tracks.  Control features assignable to track. But more than likely dedicated sysex commands and functions for this particualr unit.  to make for interesting LIve PA.

at least 1 part will be a drum sequencer for what roland calls there “Rythym Track”  .  SOme of the MIDIbox Sequencer functions could be used, as well as some midi effects type functionality.    

The next step beyond that would be a home made DSP effect unit.

ROFL   I jsut reread te thread after repsonding to arum’s post.

here is what Tk said

Remind that the development and documentation of another hardware platform possibly requires more effort than you really want. During the last years I’ve read from a lot of people who planned something similar, but finally gave up due to unexpected problems. Don’t think that bigger microcontrollers can do the IO handling much faster than a PIC18F, and keep in mind that once you are using external memories, good system knowledge and soldering skills are required. The setup of a new platform and operating system requires good debugging tools, mostly they are not free available (maybe ARM7 would be a good solution, but a useful IDE costs at least 2000 EUR!)

So, from my experience I can give you following advice: if you plan to implement a much more powerfull, reproducible, standalone DIY sequencer with fast success and open possibilities, than use a cheap embedded PC board, use Embedded Linux as operating system, and use an external PIC18F452 (running under MIOS) to handle with the control elements (buttons, encoders, LCDs, LEDs, etc.) - connected via RS232 to the PC. The advantage of this approach would be, that everybody who owns a PC (from 386 upwards) can try your software, so there is no need for bying expensive hardware for the first tests.

Best Regards, Thorsten.

this is exatcly what i am talking abotu above.

an embedded pC board using Linux, with mios for control functionality.

i came across a dsp development board by analog devices i think… will have to find the link, maybe you’d be interested.

I am no programmer either. i am starting from square one on that aspect. as i said above, if i do it myself it may take a while…but it will be done(attempted at least)

I am trying to finnish up the midi box projects i have started already( a sid and an mb64 ) then it is on to some linux programming.

I’ll try to find that link.( i just did a clean install so it’s all on a backup cd now…)

I havent bee able to stat any my porjects atm cuas eof unemployment issues  

So i am staying in the software realm for the moment.  Also there are some great boards from motorola  and the support is really great.

Hey i feel you. it’s taking so long for my projects because of underemplyment issues, and schoolwork.

but i got a core running, and got my backordered parts just now so later i have 2 cores running! anyway, this is that dsp link i found.

http://www.booyaka.com/~oncken/

maybe of some use to me. i won’t be able to start anything like that for a bit, i am trying to control my habbit of getting in to deep on things!( my enthusiasm exceeds my abilities at the moment  ;)  )

good luck on finding a job man, I know how that can be(i’m about to be looking for a new one soon myself…)

ArumBlack

Hey, they’ve even got a link to this site!! awesome!

If you are thinking of small Linux systems, check out the mini-ITX form factor motherboards.  VIA came out with the first, and now many other manufacturers are too.

Totally standard PC chipsets in a 5" x 5" low-power mobo.  Integrated audio and video, USB, ethernet, printer, serial, standard IDE, PCI and RAM slot, some with Firewire, S/PDIF digital audio, CF and PCMCIA, depending what system you choose.  Some run fanless.  And they are a lot cheaper than true industrial embedded systems.

That way you can use all the existing Linux (or BeOS or BSD or DOS or Windows) tools that other people have come up with, and set it up just like you would a normal desktop computer.  Then strip it right down to run without video, keyboard and mouse (if that’s what you want)

I’ve seen one guy build a miniITX board into his guitar pedal board, and he uses it for multitrack recording with a USB audio interface, controlled with foot pedals.  So if a guitarist can do it …  ;)

There are tools ready to go in Windows, DOS and Linux for just about everything you want - LCDs, push buttons, knobs etc.

Some links for you:

www.mini-itx.com

http://www.crudites.org/soundventures/handheld-music/

http://www.activewireinc.com/

I think the embedded Linux thing is a great idea, but if anyone want to stick to MIOS, come here : http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=concepts;action=display;num=1075654854

Thanks for the links and suggestions. as i said i am trying to finish my current projects first(and then a break to make sid tunes!) but am reasearching now, so i will look into it.key factors are reliability, and portability, since i am primarilly wanting a live performance tool.seems portable enough. audio is not a concern of mine at this stage.I originally wanted to stick to mios also, and have already joined you in the other thread.This for me is a long term project( as it involves learning things i have no concept of at the moment), so progress from me here may be few and far between right now, hopefully to improve once it gets going. i am still in a research phase at the moment.my current plan of action is to get e cheap pc system ( hopefully i can find a give away) and get linux on it and start learning. fortunately there are ppl who have done it before to learn from!

Ok, i just got 5 pos computers, tiny running some 586 processor at 133mhz. so… it begins. oh, and i found a programmer buddy to help me out! so, it may be some months for another update, but the project moves on!

There’s a Linux distro that might interest you here:  it’s designed for music and media work on slow machines.

http://dynebolic.org/

Did someone mention an Xbox earlier?  This will run on one.