Skip Navigation.
Section 0

ChromaTalk Archives: November 2012

Music and Sound Updates

Chris Ryan [21030691]

I've posted a few audio/video items that I've collected over the last few months. These are available on the Recordings & Videos page at the site.

First, Leon van der Sangen [21010301] obtained permission to post a number of sound files from Theo Bloderer and "OH." (Some of these sounds were already available at Amazona.de.)

Native Instruments includes the Chroma in their Retro Machines MK2 package for USD$79.00. And Kineticsoundprism has a sample library for Kontakt with 202 patches with 61 individual note samples per patch. £27.

Finally, Norman Fay wrote to Analogue Heaven last summer announcing an album recorded "over the last few years, using a bunch of analog synth gear among other stuff," including the Chroma. See Vietgrove on bandcamp.com. I've included this info in the Discography.

Marais

speaking of Theo, look for some new content on the Chroma on his new site by the new year: GreatSynthesizers

Norman Fay

Thanks for the mention, Chris! About 2/3 of the leadlines on our album were done using the Chroma, I have about 4 or 5 patches that i use all the time. the rest of them were done on Wiard, Synthtech and Blacet modulars. I don't think you can beat real analog for cutting through the mix without sounding harsh. Later this week, I should be picking the old heap up from the repair shop, among other things it has has the poly pressure kit added so I'm going to reprogram some of my leads to take advantage of that. I can't believe I've had the thing so long, it's surely the best 1000UKP I've ever spent.

Chroma FS in UK

Jeffrey D. McEachin [21030073+]

Not mine - spotted on Electro-Music, forwarding in case someone is looking:

studio for sale - some rare items

Description: "Rhodes Chroma - In superb working order but has a couple of marks on the top black panel (nothing major but it's not mint) The chroma has had a psu upgrade and has external midi box, 1 of the voices currently fails to autotune but the machine when autotuned all sounds in tune?" I asked the seller for more information.

an additional display for the Chroma

min.struct

Hello,

firmware 217 (october 2012) added native support for the SparkFun serial LCD controller firmware 214 (july 2010) added UART support for Parallax Model 27979 4-line x 20 character display running at 19,200 baud.

But at last the integration of such display is not easy if you don't want to irreversibly modify the shape of your Chroma.

PROPOSAL1

This is why i was wondering if the 2digit red led display of the chroma could not be replaced by a small high definition oled display ?

The idea is not mine, i saw it on a Rozzbox V2 (the V1 only had a two digit display) Here you can see what it looks like putting an oled display in a former 2digit window :

i have seen it in real : despite it's small, it's highly readable (any angle)

oled

the version ONE (with two digit display) :

llrozzbox1

the version TWO (with oled graphical display) :

llrozzbox2

Do you think it would be somehow possible to do the same thing for the Chroma ? some oled display are HD44780 compatible (but require 12V) , but not in this size of the 2digit window (only graphic display)

PROPOSAL2

Another solution would be to use a HD44780 compatible oled display without PCB (chip is on glass, the display is only 2mm thick!) and glue it (double side tape) just above the 2digit display, in order to make the ribbon cable pop inside via the junction in the middle of the chromas' panel at last, a thin partial display bezel could be added (to cover the left part of the display)

20x4_Character_OLED_Display_Module_Yellow

more information : Character OLED (PDF)

MCU communication interface
COG type : • 4/8-bit 80xx/68xx parallel, SPI,I2C
Standard PCB type : • 4/8-bit 80xx/68xx parallel, SPI,I2C • By component / circuit select.
On-chip CGROM ( 5x8 ) English / Japanese / Europe / Russia : • Hardware Select
Programming CGRAM ( 5x8 ) Max. 8 5x8 character
Compatible : IC compatible with KS0066 / PCB version, mechanical and pin are compatible with LCM
Driving Voltage
COG Module need 12V applied
PCB Module using built-in boost circuit or extra 12V power

20x4_Character_OLED_Module_White

about oled character display control : Controlling an OLED character display with Arduino.

James Coplin [16330036]

That would be perfect if it would fit and the firmware could accommodate it. I would definitely like to see such a drop in upgrade.

James Coplin [16330036]

I meant to say option 1 looked most interesting. The second looks too prone to damage and really isn't much better than the existing external display solution,

Randel Osborne [21030467]

David and Sandro-

Is there any way that a future version of the CC+ firmware could echo the Chroma Data Readout in the serial stream?

If so, the next step would be to create a "Virtual 5X20 Character" display on something like this: Serial Miniature OLED Module - 1.7" (uOLED-160-G1GFX)

min.struct

yes, that would be great, but graphical display is maybe a step too far for the UART chip ? just for your information, the oled display of the Rozzbox V2 is an obsolete Osram Pictiva, 1.0 inch, 96x36 Pixels, 1 Bit (OS096036PP10MO1B10) even with only 96x36, one can display a lot of information. See here the modes of osc. routing at 0'50 : L.L. Electronics Polyphonic RozzBox V2 Menu Screens [YouTube]. The diagonal of the window of the Rozzbox is approx 0,8" whereas the diagonal of the window of the Chroma is approx 1,25"

proposal2 would be similar with parallax or sparkfun backpack, BUT only 2mm thin, no PCB surrounding the display , just shiny black, very light (can be taped) no angle view. the only thing to manage is passing the flat ribbon between the central vertical rod of the control panel and the right side of the left hand control panel. this oled screen should natively HD44780 compatible.

David Clarke [21030085++]

PROPOSAL1

This is why i was wondering if the 2digit red led display of the chroma could not be replaced by a small high definition oled display ?

... Do you think it would be somehow possible to do the same thing for the Chroma ?...

While it is an interesting idea (in concept), I would be afraid that it might not be very practical.

The Chroma 2-digit display window is approx. 25mm wide by 20mm high.

If you were to attempt to put a 4 x 20 display + leave some room for the program number (lets say a 5x20 display), then you'd have characters that would be on the order of 1mm wide.

That would likely mean that the text would be equivalent of about a 6pt font. While this is certainly readable up close, when you're 2+ feet away from the display, that starts to become very small indeed.

Given that one of the main purposes of having an external display was to improve the user's view of the data, I'd be afraid this wouldn't be too much help.

PROPOSAL2

Another solution would be to use a HD44780 compatible oled display without PCB (chip is on glass, the display is only 2mm thick!) and glue it (double side tape) just above the 2digit display,...

The SparkFun controller provides a HD44780 interface - and it is supported by the code now - so if an alternate display (OLED or otherwise) is found that can run at 4x20 and is HD44780 compatible, then it could possibly be used 'as-is'.

While the example display has the SparkFun controller soldered on the rear, there's no technical reason you couldn't have a thin display placed where-every you want, run the ribbon to wherever is convenient for you, and then make any controller/other connections where you'd like.

min.struct

thanks for your answer.

proposal1 :

we will wait for graphical display support from the CC+ (if ever possible) ;] one really need to see those mini oled display in real life to understand how readable they are (very sharp, no angle). but you are right, because of the small size one need to be smart with how information is displayed. On the Rozzbox, the number of the patch alternates with the modded parameter of the moment. If the parameter naming si too long, the name is horizontally scrolled : (here at 2'12 with the "sync clock divider" item L.L. Electronics Polyphonic RozzBox V2 Menu Screens ) Graphical is used for osc./filt. routing : L.L. Electronics Polyphonic RozzBox V2 Menu Screens and here L.L. Electronics Polyphonic RozzBox V2 Menu Screens

proposal2 :

i will look for any availability of oled 4x20 char. without PCB. i'll get back to the Chroma's community if i get any interesting information. (12v is mandatory for those displays. I don't know where in the chroma it's most appropriate to pick up those 12v)

min.struct

Here is what i found : an oled that should be serial UART/I2C/SPI compatible. Could any electronic genius tell us if it would be compatible with the UART of the CC+ ? thanks

Serial:UART/I2C/SPI 128x64 OLED module

  • Power Supply: 2.5V to 7.5V
  • Power consumption: maximum 20mA when all dots light on
  • Communication mode: UART/I2C/SPI, detect your setting automatically
  • Receiving buffer: 256 bytes
  • Work with all microcontroller and microprocessor
  • Communication signal can work on 3.3V and 5.0V TTL
  • Default setting: UART baud 9600bps, I2C 0x27 address
  • UART baud (bps): 300, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, 115200
  • Pixels: 128x64, 0.15x0.15mm, high bright self light emitting
  • Screen size: 22x12mm
  • Product size: (WxHxD):30x28x4.8mm (1.2X1.1x0.19")
  • Simple command sets, easy to remember
  • Simple graphic engine integrated
  • 7 preloaded fonts, font’s data structure full compatible with U8Glib
  • 5 individual out put pins with High current sink/source 25 mA/25 mA, can drive LED/relay and more
  • Integrated 64MHz PIC18F26K20 MCU to process your command and graph engine
  • Wide voltage working range: 2.5V to 7.5V, fit all 3.3V and 5V application.
  • Save lots of the I/O resources: these products only need 1 to 3 I/O pins from your controller that depends on the communication type you want.
  • Save huge memory space to store font and start screen: in these product, there are 7 preloaded fonts ready for your application, and also have 16KB memory space for your user fonts, once you uploaded the start screen or user fonts, it will stored in products.
  • Easy to use: the commands sending to products are easy to remember and understand.
  • Using user fonts function, you can display any graphs or characters in any language
  • These products already integrated graphic functions such as: draw line/rectangle/circle/image, send few bytes of instruction to products, it will do it for you, that also save your lots of code space
  • You can display contents in 4 different directions: 0º, 90º, 180º, 270º(clockwise) on same screen, the product will map the coordinate accordingly.

connectsamplethumb

Jeffrey D. McEachin [21030073+]

At 02:34 AM 11/15/2012, min struct wrote:

we will wait for graphical display support from the CC+ (if ever possible) ;] one really need to see those mini oled display in real life to understand how readable they are (very sharp, no angle).

How old are you? Those of us 45 & older will probably disagree with you about the readability of small text. ;)

min.struct

i'm 40, maybe i will start complaining in a few years ;] but you would be surprised by the readability of those displays

0

Daniel Rickenbach [21010172]

you will start complaining ;-)

I'm 44 years now, a few years ago, it didn't have an problems with small things (e. g. solder SMD-parts without glasses), now I have difficulties to solder normal parts without a magnifier lens, after 40, eyes going bad very fast, I know a lot of people which have made the same experience.

David Clarke [21030085++]

... Here is what i found : an oled that should be serial UART/I2C/SPI compatible. Could any electronic genius tell us if it would be compatible with the UART of the CC+ ?

There's really two parts to that question.

The first part is a general hardware question - whether the UART of the CC+ could talk to the display.

At a hardware level - the UART is just a generalized serial interface - and so 'yes', pretty much any asynchronous serial receiving device is compatible with it (including the one noted).

That said - just because the hardware is _capable_ of talking to a given display, that doesn't necessarily mean that it will do all the things you might hope or would do it as currently programmed.

For instance - at present - the CC+ outputs its serial data at 19,200 baud. While the UART could easily do 9600 baud (or other speeds) - the code is currently fixed to run at 19,200.

So - the second part really has to do with what the CC+ code is programmed to do. The code today is set up to output 4 lines of text. What that means is that (by default) the CC+ won't be generating the special command-codes to draw graphics, or to do animation, etc.

With regard to the specific display noted (Serial Display&Keypad--0.96" Serial: UART/I2C/SPI 128x64 OLED Module Blue), it appears this unit always powers up at 9600 baud - and so to use it with the CC+ the system would have to have specific new mode added that would always start at 9600 baud, and then configure the display to run in 4x20 character mode. Put another way - if you simply plugged this unit on to the CC+, you wouldn't necessarily see the output you'd hope.

If it was desired to have a very fancy display (one that might have a different number of lines, have animation, behave differently, etc.) - I wouldn't necessarily recommend that these be done _inside_ the CC+; rather, I'd suggest that someone would be better off to create out _outside_ of the processor that is used inside the Chroma.

Specifically - all of the data to drive a custom display can be retrieved from the Chroma via the 25-pin computer interface port or via MIDI.

So - the general idea would be to create a small controller that interfaced with the Chroma on one side via the Computer Port (or MIDI) - and then on the other side had the display of your choice (perhaps a touch screen, VGA display, or other). This sort of configuration would require that someone makes a controller/controller software to interface with both - but that way would ensure you can interface with any display, and have the data presented in exactly the format you might like.

Of course, if we as a group do find yet another standard display type we want to support (still using the 4x20 display setup), then we could certainly consider adding support for it to the CC+ firmware.

Best regards,

David C.

Michael Krewitsky [21030504+]

How about an iPad to Chroma computer port adaptor and an iPad app that allowed it to be an additional display for the Chroma... Could that be done?

Marais

Leo's current iPad modified TouchOsc template works good. It's close to being finished soon we hope ? iPad Editors

all you need is a midi interface (from $20 to $140) for your ipad.

min.struct

David, thanks for the investigations, then your extensive and clear explanations ;)

UART serial oled DIGOLE oled display :

as i suspected that displaying graphics was too ambitious, "text only" was and still is my first in mind. With digole uart displays, I was just hoping for a HD44780 direct compatibility , ( Serial:UART/I2C/SPI Graphic LCD/OLED Display Control Module User Manual [PDF] / Serial Display&Keypad--0.96" Serial: UART/I2C/SPI 128x64 OLED Module White...">Serial:UART/I2C/SPI Graphic LCD/OLED Display Control Module User Manual ) and a little fun : "if order qty>10, we can preload your custom Start Screen and user font") Sparkfun backpack is also 9600baud/s by default, would it be visible if one half the serial speed from 19k to 9.6k? What is, in fact, the protocol used by the CC+? Is it standard? Is HD44780 code different from 4/8-bit 80xx/68xx parallel ? sorry for my noobe questions...

maybe such parallax chip could do the job of a third party "graphic" processor you talked about?

Propeller Demo - uOLED-160-GMD1-uSD This is a demonstration using the Propeller (from Parallax) to control a small OLED display. The display uses a simple serial protocol. It also has a uSD (trans-flash) slot built in to the device and commands to store and retrieve images, text, command scripts and data on the uSD Propeller General Information

and as size seems to matter on this list :)) here is a full line of 12 displays (oled and LCD) from 0.96" to 4.3" which share the same serial interface Display Modules- SGC - 4D Systems Shop their interface can be set in 2 modes :

SGC PmmC:

By loading the SGC (Slave Graphics Controller) PmmC, the module is 'ready to go' by simply connecting it to the serial port of your favourite micro-controller, and sending serial commands to it. The Serial Command Set for GOLDELOX can be found here: GOLDELOX-SGC-COMMANDS-SIS-revXX.pdf

GFX PmmC:

By loading the GFX (Stand-Alone Graphics Controller) PmmC, the module is then like a microprocessor which you program, using the 4DGL language (very similar to C), to control the internal graphics and external interfaces.The 4DGL language command set and functions for GOLDELOX can be found here: GOLDELOX-GFX2-4DGL-Internal-Functions-revXX.pdf

Note: At any time, you can reload the GOLDELOX chip with either PmmC which allows you to explore the differences between the two configurations.

this is just an example, but the idea would be to choose one very full line of displays which share the same serial interface so that anybody would have the choice of the size ;) (that was already your goal with the sparkfun backpack). other example, this line of product goes from 0.96" to 5"5 with SSD13xx controllers (LCD Modules, Custom LCD, Custom LCD Modules, Touch Screen, Resistive Touch Screen, OLED, TFT, LCD, LCD backlights)

about the sparkfun backpack :

does this backpack work in 4bit or 8bit parallel mode (16LF88 controller)? that seems an important point to make it work with a COG (chip on glass) oled display (e.g. solomon SSD1305 controller only work in 8bit parallel; or SPI). does the speed transfer need to be set each boot up ?

other serial backpack for HD44780 (fixed speed transfert 16F648A controller)

with (PIC16F689)

another serial backpack for ST7920, KS0108 or ST7565

this one for HD44780 looks propriatary code (74HCT595 chip)

From the "oled HD44780 compatible" side, things are not clear :

Newhaven oled looks to be avoided : Controlling an OLED character display with Arduino | ElcoJacobs.com The display was supposed to be HD44780 compatible, but it took me ages to get it to initialize properly. The folks at Newhaven couldn’t even figure out what the correct 4-bit initialization sequence had to be for Arduino. Finally I found a sequence that worked and modified the Arduino LiquidCrystal library to work with the OLED display. I also added functionality to read the busy pin of the display and to read the contents of the display.

List of manufacturer of oled displays with COG (chip on glass, i.e. no pcb, i.e. 2mm thick display) :

the advantage of getting oled displays without pcb (it's 2mm thick, weight <10g), is that you can tape them on any flat surface, so no hole or window needed. Thanks to more than 160° view angle, you can position it vertically or horizontally, no need to be face to face as with regular LCD.

well that's all. As i'm not an electronic guy, i could just bring information, not solution. I hope that one can bring out a new solution and widen the CC+ application area ;)

thxs

min.struct

Hello,

to display information from the Chroma, is TouchOSC bidirectional SysEx able (as is TBmidi stuff) now? thanks

David Clarke [21030085++]

an additional display for the Chroma (bi-directional MIDI)

... to display information from the Chroma, is TouchOSC bidirectional SysEx able (as is TBmidi stuff) now?

While your question about SysEx is certainly a valid question (and one for which I don't have the answer - as I don't currently have a TouchOSC configuration), I just wanted to clarify that the CC+ not only supports SYSEX requests for data but also supports the more common MIDI continuous controller sending of data. That means that as long as the editor/knob box/iPad app can successfully receive and display MIDI continuous controllers, then you could have parameter data automatically updated on those remote controllers.

David Clarke [21030085++]

Sparkfun backpack is also 9600baud/s by default...

That is correct; however, the nice feature of the SparkFun is that configuration settings are non-volatile (i.e., they get stored). That means that after you've configured the interface once - it will then power up in whatever mode you last set (so once you set it to 19k, it will then start up at 19k from that point on).

would it be visible if one half the serial speed from 19k to 9.6k?

It is possible. The faster speed was specifically chosen to allow the screen information to be updated quickly, so that it to the user's eye any changes in parameter data happens 'immediately'. Going to 9.6k would mean that there would now be some visible lag in screen updates (since half as much data in the same amount of time could be transmitted).

What is, in fact, the protocol used by the CC+?

There's no 'protocol' per se. The data coming from the CC+ is essentially raw serial data (e.g., 1 Tx line running at 19200, sending ASCII characters).

If you were look at the data with a communications program (hyperterm, TeraTerm, tip, etc.) you'd essentially see exactly the same data you see as text on the display. The only slight additional information is that there are a couple control codes also sent to the display which tells the display to "go back to the top" ( move to line 0, pos 0 ), so that the data always starts at the top and doesn't just continuously scroll off the bottom.

Is HD44780 code different from 4/8-bit 80xx/68xx parallel ?

Whether it is configured for the SparkFun controller or the Parallax display, the CC+ always outputs ASCII characters to the serial line.

In the case of the Parallax unit, the ASCII data is received directly by the display (i.e., the user-interface for the Parallax unit is a serial connection).

In the case of the SparkFun unit - it too also directly accepts ASCII data directly from the CC+. It additionally then converts the generic serial ASCII data into the 4-bit data used by the HD44780 interfaces. So - the SparkFun is really a 'data converter' that takes the ASCII data - but then allows you to connect an HD44780 interface.

With digole uart displays, I was just hoping for a HD44780 direct compatibility , ( Serial:UART/I2C/SPI Graphic LCD/OLED Display Control Module User Manual [PDF] / Serial Display&Keypad--0.96" Serial: UART/I2C/SPI 128x64 OLED Module White... )

The item noted is actually a serial-based interface (vs. the HD44780 interface.

and a little fun : "if order qty>10, we can preload your custom Start Screen and user font")

Many of the units that have a non-volatile storage of settings (like the SparkFun) will also allow you to set your own power-on message - so you can have it say whatever you want for a short period as it starts up.

... i could just bring information, not solution. I hope that one can bring out a new solution and widen the CC+ application area ;)

I'm certainly happy for others on the list to share their thoughts too - as I'm certain there are others out there who might have more creative thoughts than me.

Best regards,

David Clarke

Dual Pedal Assembly on eBay

Chris Ryan [21030691]

Item #261128286164, starting bid USD$85.00, no bids yet, ends November 19. "Fully tested and in excellent working condition."Item #261128286164, starting bid USD$85.00, no bids yet, ends November 19. "Fully tested and in excellent working condition."

eBay261128286164a

eBay261128286164b

Chris Ryan [21030691]

There's now another sustain pedal available: item #330830235427, starting bid USD$19.99, ends November 19, no bids yet. "The pedal shows wear on the cord, pedals and the unit. The plastic piece at the end of the cord is loose, and the bottom is missing two of the little rubber pieces. It needs cleaned and has not been tested. The pedals appear to be working properly. This is an estate find, please ask questions before bidding."

eBay330830235427

Chris Ryan [21030691]

On 2012-11-15, at 3:48 PM, Chris Ryan wrote:

Item #261128286164, starting bid USD$85.00, no bids yet, ends November 19. "Fully tested and in excellent working condition."

Sold for USD$87.00.

On 2012-11-15, at 3:48 PM, Chris Ryan wrote:

There's now another sustain pedal available: item #330830235427, starting bid USD$19.99, ends November 19, no bids yet. "The pedal shows wear on the cord, pedals and the unit. The plastic piece at the end of the cord is loose, and the bottom is missing two of the little rubber pieces. It needs cleaned and has not been tested. The pedals appear to be working properly. This is an estate find, please ask questions before bidding."

Sold for USD$41.00.

Chroma S/N 21030828 Sold on eBay

David Clarke [21030085++]

It looks like another Chroma (21030828) has sold on eBay recently (for US $3,995.00).

Just curious - is the new owner here on the list?

One of the pictures from the auction:

eBay261126786130

EPiCK for Chroma?

Luca Sasdelli [21010226]

Hi all,

it's quite a long time I'm watching to an interesting project: EPiCK. It is an optical sensor for keyboards, and recently the author has added polyphonic aftertouch. Just thinking to Chroma contact issues and improvements.

BTW: in case of such as a MIDI interface, would be possible to connect it someway to CC+ without occupy the external MIDI box?

Daniel Benoit [21030109]

Hi regarding the optical keyboard sensor

Midi9 as been doing this for years now and it works perfectly, I have one installed on my custum built "real" grand piano action midi controller it works in position and velocity sensing, and it as 1024 steps of resolution (10bits) that is scaled down to midi resolution (7bits).

It's not cheap...the 88 notes version is arround $1500 for 88 notes (it can be scalded to any key number like 76 notes) but it's the price to pay to get the "Holy grail" of midi controler mine was installed on a Yamaha CP70 76 notes stage piano action.

Installing it on the CHROMA would be easy, but a bit to expensive I think...

Info: MIDI 9 - Add MIDI to Any Keyboard Instrument

Paul DeRocco [21030230]

The Midi9 system works well, except that when placed under the front of the keys, it is susceptible to light leaking through the cracks between the keys. Mounting them inverted over the backs of the keys where it is dark would work better. Also, any optical system eventually gets dust build-up, and needs cleaning.

It is fairly expensive, but not intrinsically so. If it were mass produced on a larger scale, it could be quite cheap.

Go to next message in thread, December 2012

ROM Chips Sold on eBay

Chris Ryan [21030691]

Item #251184791135: these have been for auction numerous times; they finally sold for USD$100.00.

eBay251184791135

Paul DeRocco [21030230]

Gee, you can buy a bunch of blank EPROMs and an EPROM programmer for that.

Andrew Howson [21030209]

From what I've read 2716 eproms require 30mV@25V and 100mA@5V, which from my experience is pretty unusual and rarely supported. I'm not suggesting the buyer got a good deal with this auction, but I doubt they could have bought a competent burner for 2716's for less than $100.

Paul DeRocco [21030230]

I can't say that I've tried any more units than the one I've got (GQ-4X at $100, which works fine), but the few cheaper ones I looked at on eBay all claim to support 25V 2716 and 2732 parts. Those currents are still well within the capabilities of a USB-powered device.

Andrew Howson [21030209]

The GQ-4X has a list price of $149.99 USD.

Anyhow, I looked up some info on the GQ-4X and 2716's and found a post suggesting the 2716 doesn't actually have a standard, and that different manufacturers used different specs for the voltage rails (and while most were dual-voltage, some were even tri-voltage). If true I suspect that would have something to do with my experience in the lack of 2716 support (whether that be user error, or a general lack of support for the full spectrum of 2716's, I don't know).

Here's the post if you're interested: Tech: Willem GQ-4X Programmer and 2716 EPROMs

Paul DeRocco [21030230]

The GQ-4X has a list price of $149.99 USD.

That's why God made Gentiles. ;-)

Anyhow, I looked up some info on the GQ-4X and 2716's and found a post suggesting the 2716 doesn't actually have a standard, and that different manufacturers used different specs for the voltage rails (and while most were dual-voltage, some were even tri-voltage). If true I suspect that would have something to do with my experience in the lack of 2716 support (whether that be user error, or a general lack of support for the full spectrum of 2716's, I don't know).

Here's the post if you're interested:

I went through my old stock, and I've got several sets of Chroma EPROMs, one with actual official printed labels, two that are hand labeled. I just regard them as spare parts that I can erase and reprogram if I ever need them. They're all AMD, and I suspect that's what got used in most of the Chromas, although I vaguely remember we used some Intel parts in engineering.

(I also found some pretty TI TMS2732 parts, with gold frames around the windows. I have no idea how I got those, since we never used 2732 parts in anything.)

Anyway, if anyone here needs replacement Chroma EPROMs, with a little care you can find a programmer and the necessary parts on eBay for much less than $100, and when you're done you still have a useful tool you can use in the future.

Rhodes Chroma Synth seeking experienced technician (east dallas)

Chris Ryan [21030691]

See Craigslist listing #3426152135. I contacted the owner, who writes, "I've had this Chroma since summer this year. I found it in a friend's warehouse and he said it hadn't properly booted since he owned it. On boot, It would display the autotune failure message, so I've chopped out the power supply and attempted to build a board for the new PSU. I'm pretty scared to actually hook it up though since my training in electronics is pretty slim. This thing was in bad shape, but I've managed to clean it up nicely so far. Best of all, it was free so putting any money into it to fix it is beyond worth it."

This is Chroma 21030472, new to the registry. There's a set of pictures on Flickr.

ipad interface for Chroma

David Hobson [21030506]

Hello,

I am, as I often am, a little confused as to the status of an iPad editor for the Chroma. Is there an iPad editor available either from the apple store or somebodies internet page. I have the CC+ upgrade and a midi interface and i am looking to purchase an iPad for programming the Chroma (it would be soooo nice).

Any thoughts?

Thanks for your time.

Leon van der Sangen [21010301]

Hi David,

Here you will find what you need: TouchOSC iPad Template Modifications

David Hobson [21030506]

Thank you Leon!