[Blindapple] Possible to Emulate the Blackboard Card?

[Al Puzzuoli]

toward the end of my time as an Apple IIe user, I saw a demo of this 
card. Basically, it took the text of any Apple program, and output it to 
either an Echo or Votrax synthesizer. The advantage was apparently that 
all the analysis and TTS  took place at a hardware level, bypassing the 
need for TexTalker. Therefore, virtually all text based apps could 
theoretically be read. I never got to try the Blackboard and don't know 
how well it worked in practice, but am curious as to whether anyone here 
ever used it, has any memories of it, or whether it could possibly be 
emulated some day? This is all the info I can currently dig up about the 
card:
http://www.abledata.com/abledata.cfm?pageid=113583&top=0&productid=94437&trail=0
--Al