[Jay Levin]

You act as though the plug-ins came first, and then "stupid Pro Tools" came around and didn't support them properly. The opposite is the case.

TDM was conceived as a DSP system running not on your computer (like a native system) but on the "TDM computer" -- i.e., your core and process cards. That box-within-the-box handled every single bit of real-time audio processing.

RTAS was an add-on to this system, enabling the TDM computer to route signal out to the "outer box" for processing and then back into the TDM environment. Essentially, RTAS is an exception to the basic TDM premise, made in response to user demand to utilize the host computer's CPU.

Any routing to the native environment has to be tightly controlled or else the TDM environment falls apart. HTDM is yet another add-on that provides a second method of routing audio to the native system -- again, created in response to demand for native CPU utilization on busses and masters. AltiVerb, for example, simply could not run as a pure TDM plug-in, but it does just fine as HTDM.

For processors commonly used on busses and masters -- reverbs, mastering limiters, etc. -- if a plug-in doesn't support either HTDM or TDM, then as a practical business matter, that plug-in's publisher is simply not serious about the TDM platform. That's not a criticism, it's just a fact.

JSL