Telex: Teletype expanders


Is there a Teletype 1.41 hexfile anywhere? Installing the toolchain to compile is it proving impossible right now due to Microchip/Atmel’s stupid non-responsive registration process.


@jnoble - Thanks for all the kind words. I’ve received an enormous amount of help and support from a ton of folks - directly and indirectly. Couldn’t have done all this without it. (Sent you a PM on the firmware. )

@ppqq - I was going to put together some snippets/scenes while traveling over the coming month. I’d love to see everyone’s contributions compiled somewhere for everyone to learn from (including me). Not sure what the best place would be.

@tehn - thanks for that. The last of the DMs should go out tonight.

@dadek - YAY!!! Let me know how you get on with it. :slight_smile:



  1. All DM notifications are out for reservations. If you didn’t hear from me, I must have screwed something up. Please reach out.

  2. All preorders that have filled out the google form with email and physical addresses as of this message have been boxed, weighed, and sent details about the final costs (including shipping and insurance).

  3. All PayPal completions as of this message have been processed and issued tracking numbers. All but a few of the packages have been dropped at the post office. They are going first thing tomorrow. :slight_smile:

Upcoming schedule:

Orders that are finalized at PayPal tomorrow will be able to be shipped on Saturday morning (PST). After that point there will be a week+ delay before a) any additional shipping and b) any additional estimation of shipping costs as I am going to be out of the country.

The next shipping date will be May 15th. I should be able to start calculating shipping costs for new folks that have filled out the form that Friday/Saturday to give you a day or so to do your PayPal magic. Don’t freak during the week - I’m not near the stuff I need to box and weigh. :wink:

After that, it is early June before I can calculate shipping and handle transactions - for a ship date of June 5th.

Final thoughts: you all have been amazing. So prompt and supportive all throughout the process. This experience has been fantastic!!!

I can’t wait to see all of the creative things that you do with the expanders. Please post and share your creations - it is what makes all of this worth it!!




Another shipping update…the kids are moving out en masse:

I’ve processed all of the PayPal transactions as of this morning. Dropping your boxes in the mail shortly.

I have a few more that have filled out the web form and are ready to be packed and weighed. If you want to get in on tomorrow’s delivery, I suggest getting to that web form and being at the ready for PayPal. I should be getting to packing the latest round late afternoon - which is when my last glance at the web form data will happen before next weekend.

A Note on International Payments

PayPal is pretty greedy with fees. To the extent possible, please check that what you send will get converted into the full amount for your hardware, shipping and insurance. We’re coming up a bit short all over the place. Normally I’m not the kind of guy to sweat a few bucks, but with the number of international orders that we have this is starting to add up. I’ll ping you if I find a sizable delta; thanks for helping me with this. :slight_smile:

I’ve affixed the v1.4.1 hex for the Teletype that I’ve been using. Please consider this unofficial and do consider running the 2.0 firmware @sam has in beta. Major improvements and enhancements in that firmware - for those in the mood for some beta action. (82.6 KB)


im really impressed how you’ve executed all of this, its awesome. im sure i’ll be just as impressed with the modules when they arrive. i’m happy to throw in a few extra bucks if it helps. i know its a labor of love… let’s keep it that way :slight_smile:


@systmcrsh - Thanks for the nice feedback. I can’t wait till you get your units - tracking shows that they are on their way. :slight_smile:


I’m a few hours from taking the Saturday shipment to the post office. At that point, it will be at least a week before I can ship any other reservations.

This means:

  • In the next seven days if you put your details into the address collection form, I won’t be able to box, weigh and price your shipment until the weekend.

  • If you send any funds via PayPal, I won’t be able to print your shipping label and drop your TELEX into the post until the weekend.

Don’t sweat the delay, the next shipments will start up again at the end of the week. This is a good opportunity for you to get those details in, however. After next weeks shipment it will be two weeks before I can ship again (for the June 5th shipment).


If you are running multiple units of the same type (e.g. 2xTXo or 2xTXi), keep in mind that the address jumpers are unique for each type of expander. This allows you to have up to eight of each type (which is totally ridiculous - I can’t imagine anyone would ever do this).

Here is a sample scenario:

A user has two TXo and two TXi. One TXo and one TXi should be without jumpers. The next TXo and TXi should have the first jumper position covered.

  • TXo #1 - no jumpers
  • TXo #2 - first jumper covered
  • TXi #1 - no jumpers
  • TXi #2 - first jumper covered

As per the Quick Start Guide, each additional unit extends into the address space. For example:

To reach TR and CV output 1 on TXo #2:

  • TO.CV 5 V -5


Dumb question here. Can I daisy chain the TXo and TXi or do they both need to be plugged into the teletype directly?


Absolutely. That is why the two ‘ii’ headers on the backs of the units are offset from each other.

Here is an example where I’ve daisy chained 8 TXi and 8 TXo (the maximum number of TELEX that you can connect). Each side is connected to the iiBackpack once, each unit then connects to its neighbor for the ii signal. I’m running a script that pulses all 36 trigger outpus, puts random CV values on all 32 TXo CV outputs, scans through the 32 TXi param knobs, and sets the 4 Teletype CV outputs to the value of the currently scanned param knob (like a 32 step sequencer). Halfway through I turn on the TXo pulse dividers to get a 32 output clock divider.

As I mentioned previously, totally nuts:

It is completely solid and has no problems with calling to addresses that aren’t present (like TR 5+). Definitely the largest configuration that I’ve tested. Happy to see it working so well!!!

All units for today’s shipment are in the post and everyone should have their tracking numbers.

Next shipment is a week from Monday. Final pricing can’t start going out until Saturday at the earliest (a week from now).

For all that receive their TELEX this week - good luck installing and have a good time experimenting!! Please reach out to the forum here if you run into any difficulties or have any questions.


Echoing the initial reports (I got mine Friday) the modules are beautiful. Thanks a million @bpcmusic! I haven’t had much time to explore but I’m dipping my toes into the OSC commands mainly and very excited. I do have a more general question in the meantime. I’m curious how folks with shallow skiffs are getting on with the TT+Backpack+II. Things are awfully snug in my Frap Tools Plus Case… Maybe we could explore alternative II cable end connectors to make the combo more skiff-friendly? (Has this been an issue for anyone else?)



@ppqq - Thanks for the nice feedback!!

Those Frap Tools cases are super-tight. Hard to get much of anything into them. I can only really fill mine with quite shallow modules. Even then, just getting the power connectors in is tough.

You might be able to cut back the shrink wrap on the jumper cables that come with the TELEX to the edge of the plastic connector (away from where the cable comes out) and bend the cable a bit more to gain some room. You will risk wrecking the connector by either cutting the cable or (more likely) pulling the lead out of the connector.

You could also try a more traditional ribbon connector with a right-angle connector. Something like this:

Finally, if you are feeling really adventurous, you could desolder the female precision headers from the back board of your TELEX. Then, you can first solder your Teensy more closely to the back board and then solder the two boards together. You will save some serious depth that way (and also make the unit rock-solid secure). That is, at the expense of potentially causing a problem during the surgery and complicating any future debugging if there is an issue.


I should note that you don’t have to plug the iiBackpack into your Teletype. You can power it externally using a separate power connector and run a jumper from your Teletype to any of the pins on the iiBackpack. In this configuration, you will ignore the female headers on the back of the iiBackpack altogether. That will save you depth on your Teletype.


Let us know what you end up doing!!


Thanks for the thoughts! My gut instinct is to go for the more traditional cables. I have a few (for my ansibles) and they do fit much more comfortably. That said, the idea of decoupling the backpack is intriguing. I chatted w/ @tehn a while ago about his new case design and we riffed on a bus along the top or bottom edge of the case and I may experiment with that too.

Regarding the Frap case, it’s worked out for me mostly so far though flying busses are a PITA and I tend to swear a bunch when I have to move anything around. Really like the design (and super nice folks). All of that said, I think the ISMS will be even tighter (I think it has a 41mm max module depth vs. 43 for the Frap PLUS) although power is tidier since it’s tucked up top under the 1U row (right?) Id’ be interested to get reports from ISMS owners (@scanner_darkly?)

Anyway, this is all pretty first world. Thanks for indulging! :blush:


it was a tight fit but i was able to get teletype+backpack wired up w/ 2 telex, ansible, and white whale into an ISMS. The included connectors with the telex didn’t fit but I had a few extra of the ones included w/ ansible which worked out. I’m not sure how many more cables you could run under there if you were adding additional units, but while a little snug I got all of that situated and working nicely


Following up on this since this may give me another way around my shallow skiff woes. Any downside to daisy-chaining? (Sorry I don’t get the electrical bits so I have to ask!)


i ordered both iiBusboard and iiBackpack just in case one would work better than the other - should have them next week and will report back!


@ppqq - I don’t think it makes any difference. The true thing that is needed is the iiBusboard or iiBackpack for when you have 4+ devices on your bus.

I like to chain between TELEX units in my installations in order to minimize the cable mess.

As a general rule, one is supposed to keep the i2c cable runs as short as possible. With the various configurations I’ve played with (short runs to adjacent units), I haven’t seen any appreciable difference.


After reading the Telex quick start guide I have a newfound appreciation for the potential to tear the fabric of the universe. I will endeavor to avoid causing the swirling vortex in the sky.

:joy: :mushroom:


I used my Telexes (2 each TXi and TXo) in two performances over the weekend. The second patch featured a 7-oscillator(!) drone voice courtesy of two TXos’ oscillator outputs and two chained Intellijell Quadratt tile mixers & a Synthrotek/MST VCF. Everything worked perfectly during both sets!

It is a challenge to set up that many outputs for oscillator mode with the Teletype’s limited number of commands per script, but creative use of loops and the stack got the job done.


Hooray!!! Would love to have seen and heard it! Any video or audio??

Moving this over from the 2.0 thread…

Great idea! Let’s see what I can make happen. :slight_smile:


If anyone is looking for a fun 1 or 2x TXo Scene, here’s something I made for wild, metric gate creation: