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ChromaTalk Archives: August 1999

Keyboard Magazine Articles

Chris Ryan [21030691]

Keyboard Magazine has very kindly granted permission for me to "reprint" articles from their magazine on the Chroma site. So I've posted these articles:

Keyboard Report: The Rhodes Chroma (August 1982), Dominic Milano. A review of the Chroma.

The Rise and Fall of ARP Instruments (April 1983), Craig R. Waters. A history of ARP, which designed the Chroma but went bankrupt before it could be commercially produced.

The Synth That Survived ARP's Fall (October 1993), Mark Vail. Consists mostly of an interview with Philip Dodds. Similar to the chapter in Vail's excellent book "Vintage Synthesizers."

The last two, especially, are very interesting reading.

Unfortunately, I seem to have lost my copy of the September 1982 Keyboard magazine. It has the following article in it: The Apple II/Rhodes Chroma Interface, by Bob Moog, page 58.

If anyone has this, I'd appreciate a photocopy (or better yet, the article text).


Christopher Now

If anyone has this, I'd appreciate a photocopy (or better yet, the article text).

I will look for this tonight - I have a box of Keyboard Mags in my garage dating back to '78. I'm such a packrat!!!


Dave Bradley [16330135]

I still have the actual Chroma Interface Manual (and the Apple card), if that would be of any help.

Chris Ryan [21030691]

I have the Interface manual. I just thought the articles would be of general interest.


Chris Ryan [21030691]

Keyboard Magazine: Bob Moog on the Apple II Interface

Thanks to Christopher Now for providing a copy of the Bob Moog column from the September '82 Keyboard magazine, and a scan of the photo. I've added the article to the site: The Apple II/Rhodes Chroma Interface.

This is an historically interesting discussion of pre-MIDI performance recording issues, and discusses some of the hardware limitations of a non-multitasking computer limited to 48K of memory. (I remember that I thought it was INCREDIBLE that my Apple II could capture 1700 notes from my Chroma!)


Re: Chroma voice board

Go to first message in thread (July 1999)

Jerry Leonard [21030100++]

I need the 3 voice boards, I have a chroma that is missing them. I sure wish the case was repair. Can you help me out? Thanks Roger

I may be able to sell you the 3 boards. I have an extra Chroma . Let you know in a week. I'm getting another Chroma and will probably part out the boards.

Roger John Lesinski Jr wrote:

Roger John Lesinski Jr

Thank you very much. Please do let me know, I am very interested, Roger

Bernie Bean [21030671]


I also need a Chroma voice card if you have any left over.


Ribbon cable connector broke!

Tim Siefkes [21030850]

While trying to troubleshoot my Chroma last week, I accidentally bent and snapped a pin on the connector on a 16-lead ribbon cable from the motherboard to J24 right underneath the Panel Mode membrane switches. Unfortunately it seems to be "hard wired" to the motherboard and I'm at a loss as how to go about fixing this. Any suggestions??? I don't even know if I can replace the cable by itself.

David Clarke [21030085++]

Which end did you break? If it was the J24 end (the end on the I/O board), then you may be able to 'replace' the broken pin by soldering on to the stub (if any left) or by soldering a pin directly to the wire (which used to be hooked to the broken pin) and bending that around the connector so that it will get pushed into the socket with the other pins. Neither of these ways are ideal, but will sometimes get you out of a jam.

Many electronics places sell replacement ends for ribbon cables - you'd just have to cut off the old connector and squeeze on the new one. You have to be a bit careful with these since some manufacturers use different standards as to which pin goes to which ribbon-cable wire.

Likely the cleanest way to go is to get a replacement ribbon cable - you should be able to get one for about $5.00 or so. Get one with a connector on both ends. On the channel mother-board end, you'll have to desolder the old cable - and solder in the new one (of course, you'd have to remove the channel motherboard to do this.)

Now, if you're really lucky, you might only have broken off pin 7 which appears to be unused anyway...

Good luck!


Tim Siefkes [21030850]

Yes, it is the J24 end that bent and snapped a pin. It must not be pin 7 because the Chroma behaves very strangely right now. It's one of the outside corner pins that broke. It seems like a huge undertaking to get the motherboard removed from there and do the replacement work. I might try the bending the wire around and into the socket first. That seems like the easiest way to go at first. I'd like to replace the entire cable end, but being hard-wired to the motherboard like that makes it extremely awkward to carry the piece around with me to look for an exact replacement match. Thanks for the tips!