Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!rpi!ego From: ego@aix01.aix.rpi.edu (Erik G Olson) Newsgroups: comp.sys.ti Subject: Re: info about TI-99 emulator Message-ID: Date: 17 Apr 91 06:45:48 GMT References: <1991Apr16.200420.26467@forwiss.uni-passau.de> Organization: Rensselaer Polytechnic Institute, Troy NY Lines: 37 Nntp-Posting-Host: aix01srv.aix.rpi.edu This sounds great! Some thoughts occur to me about two things, speech and graphics. One, speech is probably quite hopeless. But I'm convinced of it. Here some reasons why, or maybe they won't be new to you. The TI speech data, those rather short strings of bytes that cause the speech to form, are complex control codes which regulate a series of seven or eight filters which in turn interconnect via feedback. Because of the extreme specialisation of this hardware, very little data is actually needed to represent the otherwise complex total of audio data. The hardware is specifically tuned to the modeling of human speech, unlike nearly all other speech hardware. (Including the new Disney Sound Source, which sports a large vocabulary of real samples of real speech parts, which it modifies before sending to a plain old 8-bit (logarithmic) D/A device.) On the other hand, the PCjr speech card, last seen around 1983, contains a TI chipset for speech, but might have been a different version of the chipset used for the 4A. I don't know anything about the PCjr's bus, but if these cards can be scrounged up from somewhere, perhaps they can be made to work in a PC? Just a wild idea. And about graphics: would it be so far-fetched to include the full resolution of the 9938 chip while you're at it? It looks to me like that would be rather simple after the basic 9918 functions were programmed. After all, the 9938 is much cleaner than the 9918 in terms of memory layout. And a lot of programs that do come out these days are designed to take advantage of the extra hardware; I bet anyone serious enough to use a TI emulator or rich enough to have a 386, would be the kind of person to be writing software for a 9938 card. But then again, you're just doing this for fun, I take it. -- =======================+========================================= Erik G Olson "There was virtue in the world before there was orthodoxy in it." ego@pawl.rpi.edu --The Independent Whig