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GenEdit ST Chroma Editor

By Dave Blees [21030552] <>

The GenEdit ST editor/librarian program from Hybrid Arts provided versatile and user-friendly programming tools to Atari ST users, and was developed by Tom Bajoras for Hybrid Arts in the mid-80's. My Chroma editor for GenEdit provided the following interesting functionality:

Patch Librarian Screen

Screen 1

All functions of the Syntech/Chroma Cult i/o box accessible via 'Set Split-46' can also be set on screen 1 of the GenEdit editor. Of particular note are the Base Channel assignment via sysex, and on-screen MIDI controller assignments.

Transpose & Link functions are provided here, as well as assignment of the Program Sequence Footswitch "next program" number.

Note the very obsolete BBS contact info below the title bar. I left this in, along with my BBS "handle" pseudonym for historical purposes. Please DON'T CALL that number, as somebody is probably using it these days!

Screen 2

Most Control, Glide, Sweep, and Envelope parameters are controlled here, corresponding in general to most of the Chroma panel's "upper row" parameters. The graphical Envelope functions are constrained to the Chroma's actual "possible values", so their onscreen movement is not entirely flexible, but will accurately portray real A-D-R envelope values.

Screen 3

VCO, VCF, and VCA functions are controlled here. Detune and a redundant 'Patch-1' algorithm select are also located here, mostly due to screen real estate concerns.

Screen 4

This screen contains a single adjustment, for the 'Patch-1' algorithm selection. The graphical patching diagrams are entirely for informational purposes. I included this screen mainly to do away with having to refer to the diagrams provided on my increasingly worn and faded "Parameter Chart". The chart was then thankfully retired to an archival location.

Screen 8

This screen is simply a documentation page, providing additional and critical information to the GenEdit/Chroma user. Note that there are still 3 unused screens available in GenEdit, which were, of course, "reserved for future development, " which has never happened as yet...


This Editor is designed to work with a Rhodes Chroma equipped with a Syntech MIDI interface. It has been tested using a Rev. 14A Chroma, and results with any Chroma other than serial #0552 may vary! Some special features should be noted:

  • Whenever "program Changes" is enabled via the Chroma panel or screen 1, continuous controller data is transmitted in addition to the edit voice data, so that you can hear the edit effect while the mouse button is held down.
  • The following screen controls generated MIDI controller info:
    • ALL sliders on screen 3
    • Sweep Rate and Wave Shape sliders, and all Envelope points except Delay on screen 2
  • Controller assignments in the Syntech box (screen 1) will override the Editor's controller output, rerouting the slider controls to emulate the assigned controller device.
  • The Editor is indifferent about the Chroma's MIDI channel. It should be noted, however, that editing with the Chroma's MIDI THRU ON seems to encourage an occasional 'MIDI Overrun' error while editing.
  • One set of Interface Box parameters is saved and loaded with each voice file. This data is transmitted to the Chroma every time a voice is sent. Editor changes to the Interface Parameters while editing ANY voice will always affect the entire bank. For example, if you edit and keep the controller assignments in voice 5, the same parameters will appear when you select voice 6 (or any other voice), regardless of the settings last time you saved voice 6.
  • 'Edit A' and 'Edit B' are separate buttons only for Chroma switching. They can both be regarded as 'Edit A OR B' for screen editing purposes.

For some reason, as of today [July 2005], I have not been able to get all of the Transmit/Receive functionality to behave properly, so even though my Chroma and ST seem to be fully functional, I suspect there is an issue with my Syntech i/o card, or possibly some software versioning mismatch, or maybe just some silly little system tweak that used to be a habit for me and I have since totally forgotten. The last time I really used this system was 10 years ago, so obviously some brain-bits have fallen by the wayside since then. I'll post an update here after attempting to run Tom Bajoras' new GenEdit version, and when & if I figure out the hangup.


Recently, Tom Bajoras has released an updated freeware version of GenEdit ST that includes support for many more instruments than the 80's version, plus some cool extras, and most importantly, is no longer copy-protected. (Amazingly enough, my own GenEdit v2.0 key disk still actually works on my Atari!) See Tom's download page. The "CHROMA.TEM" Chroma editing module included in his archive is indeed the very one I programmed ages ago.

A GenEdit '.TEM' file is pretty much just the user-interface half of the editor. To use CHROMA.TEM for editing, you also need to have the Chroma configuration file (the actual code which does the GenEdit dirty work), which is included with misc. other instruments in one of Tim's archives as E_MISC.CNX. Here's a tidy little archive file that includes all the necessary bits, as well as one bank of sample Chroma patches: