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Keyboard Spec Sheets

These minor articles reported new Chroma-related products in Keyboard magazine.


From the April 1982 issue (Volume 8, No. 4, p. 73).


The Chroma is a 16-channel polyphonic synthesizer with split-keyboard capability, 50 user-presettable programs, 100 taped voice programs, and digitally-based programming and tone controls linked to 16 oscillators, 16 filters, and 16 VCAs. The keyboard is touch-sensitive. All operating, programming, and tone controls are generated in the computer with software, giving expanded access to all the oscillators, filters, and amplifiers in the instrument. Thus, the basic architecture of the instrument can be changed to allow for varying combinations of oscillators, filters, and amplifiers. Also included in the instrument is a computer interface, which enables the instrument to interconnect to an Apple II computer. Interfacing for TRS-80 and other personal computers will be available soon. The unit also features built-in diagnostics which include automatic tuning, automatic oscillator, filter, and amplifier checks, and a circuit board and battery check. The keyboard can be split at any point and the split can be stored in memory to be recalled on command. Other programming capabilities include a program link which allows two programs to be overlaid. Linked programs can be transposed separately or together. An arpeggiation mode is also included. The instrument comes with two foot pedals, a heavily padded ATA Anvil case, a standard cassette tape with 100 voice programs, and two owners' manuals. Rhodes, 1300 E. Valencia Dr., Fullerton, CA 92634.

Computer Interface

From the March 1983 issue. Thanks to Jack Colburne [21030142+] for the scan.


The Apple interface package for the Rhodes Chroma polyphonic synthesizer lets the 48k Apple II Plus computer with DOS 3.3 and a 16k RAM card set up synthesizer voices, simulate keyboard velocity and pressure, store and load programs from the Chroma's cassette interface, and do everything else that the player has been able to do with the keyboard and various other hand and foot controls. The package also includes a sequencer program which allows the operator to store a sequence of up to roughly 1,900 notes in the Apple's RAM, then play it back while overdubbing another part and storing the final product on disk with desired tempo changes and other editing. Communication between the Apple and the Chroma is via two interrupt-drive 8-bit parallel ports, plus associated control signals. A complete command set allows the Apple to query or set the status of the Chroma mainframe and control panel. Protocols are provided for exchanging data packets for real-time synthesizer programming changes. An interface card, which plugs into the Apple I/O slot, connecting cables, and software disks with sample sequencers and program groups are included in the kit. A cable for controlling a second Chroma or the new Chroma expander chassis is optional. Two disk drives are recommended. Price of the kit is $495.00. Rhodes, 1300 E. Valencia Dr., Fullerton, CA 92634.