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Teletype and ER-301 Basics


Can teletype run multiple scripts simultaneously?
Does the 8 lines limitation affects the number of assigned gate/CV’s via i2c?


My understanding is that Teletype is single-threaded, so there’s no simultaneous script execution. In practice though, scripts execute so fast that you don’t really notice this. I didn’t realize they weren’t executing simultaneously until scanner_darkly told me.

There are 10 total scripts, 6 lines each. Everything is limited by that. However, there are clever ways to get around this. For example, you can use a loop prefix to send gate signals so a bunch of SC.TRs in 1 line. With the grid ops, you can define buttons and faders in mass with a single line of code. So it’s perfectly conceivable that you could use all 100 SC.TR and SC.CVs. Whether or not there’s a scenario where that many makes any sense is another story. :slight_smile:


of course :slight_smile:
Does " the scripts are 10 in total" mean that you cant run more than 10 scripts?
or this is the max no a scene can have?


There are scripts 1-8, and 2 special scripts, metro, and init. A scene includes all of them.

Init runs when the scene is loaded. Metro runs on a clock (user defined interval). In the original firmware, each of the scripts 1-8 are run each time you send a trigger into the trigger inputs 1-8. With the current firmware, any of the 1-8 scripts can additionally be called from one of the other scripts, as well as from grid ops events (button or fader press).

So a scene is limited to these 10 scripts. But you can store scenes. And there is an op to recall a scene that you can use in a script. You can also run scripts and recall scenes using grid control.


Great. Thanks a lot Joe!


Teletype 3.0 is officially released with ER-301 support, FaderBank and W/ support too.

@scanner_darkly, @bpcmusic, @odevices and @Joe too have all made a terrific contribution to the world of generative and programmable sound architecture, along with interlinked communication between devices that extends our abilities on an unimaginable seriously exponential level.

The firmware update and documentation can be found here:

or on the Lines thread here:


Not sure I deserve a mention here, as I haven’t had anything to do with this other than testing. But totally agree this is worthy of celebration! :slight_smile:

The Eurorack bar has been raised by the great vision and work that’s been done here. I am looking forward to many happy hours of creating music with these devices!


Trying to get Teletype to talk to er301

used http://wiki.orthogonaldevices.com/index.php/ER-301/Teletype_Integration#Required_Hardware_Connections

Rev7 board

typed in all commands

SC.TR port α Set TR value to α (0/1)
SC.TR.TOG port Toggle TR
SC.TR.PULSE port Pulse TR using TO.TR.TIME/S/M as an interval
SC.TR.TIME port α time for TR.PULSE; α in milliseconds
SC.TR.POL port α polarity for TO.TR.PULSE set to α (0-1)
SC.CV port α CV target α (bipolar)
SC.CV.SLEW port α CV slew time; α in milliseconds
SC.CV.SET port α set CV to α (bipolar); ignoring SLEW
SC.CV.OFF port α CV offset; α added at final stage

in live mode and got nothing so far.

anyone have a simple script that will work on teletype to test it


i think since a recent Teletype firmware the 301 address has changed and must be configured as 0x31 in the ER-301 (as per the bottom of the wiki page you linked, which predates the addresses changes).


still does not work, tried all addresses.

all connections, checked etc.


Thanks, the address was indeed an issue on my side!


detailed info on which address to use:

the above applies to the teletype official latest release 3.0 (please note the version number was changed from 2.3 to 3.0 in the final version).

there is also a corresponding change that needs to happen in er-301 firmware, not sure if it made it to 0.4 but the above will work either way as long as you use the addresses listed in the post above.


Hey everyone! I’m a regular over at Lines, but I’ve been lurking here ever since I submitted an order for a 301 last month. It arrived earlier today and I’m having an absolute blast getting started.

One quick TT question if I may, around some weird behavior I noticed while using the Clocked Doppler Delay. I’m sending SC.TR.PULSE to the clock parameter (via port 1) just fine, but I get a noticeable - albeit temporary - warble in pitch/multiplication when I press the TAB key on the keyboard connected to my TT when switching between live/pattern/scripts; it’s almost as if switching between modes on TT sends a little offset for a split-second to…something. Tried driving the delay clock with a physical trigger from TT instead, connected to A1, but the same thing happens.

Am I overlooking something obvious? :thinking:


i assume the delay would exhibit such effect if the interval between triggers fluctuates. are you triggering from a metro script? it’s possible that some actions would result in timing fluctuations but switching modes shouldn’t be one of them (unless HID code runs on higher priority than timers, i’ll take a look). i’ll do some measurements.


That’s exactly it - both triggers were indeed running from the metro script. If it helps you narrow things down, the fluctuation doesn’t occur when I navigate between scripts on TT - only when switching between modes.

Thanks for taking a look! I’m mostly just amazed at how quickly I was able to get TT and 301 talking to one another.


that’s very helpful, thanks! the very likely reason is - it will write the latest mode to flash (so it starts in the last mode used when you power it on), which happens every time you change the mode, but not when you just switch between scripts. i’ll disable it and test.

if this is the actual reason we might need to disable that feature or maybe make it user selectable.


did some measurements and confirmed the issue. continuing the discussion here: https://llllllll.co/t/teletype-3-feature-requests-and-discussion/16219/182


Thanks for the follow-up and the detailed description over on lines!