Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!umich!samsung!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!ucselx.sdsu.edu!petunia!news From: gminette@polyslo.CalPoly.EDU (The Silver Dragon: AKA G. Minette) Newsgroups: comp.sys.apple2 Subject: Re: Ensoniq Keywords: Ensoniq, IIgs Message-ID: <26473ab8.43a8@petunia.CalPoly.EDU> Date: 8 May 90 21:31:36 GMT References: <1983@polari.UUCP> Distribution: na Organization: The Society Of People Who Put Things On Top Of Other Things. Lines: 66 [lots of stuff about how everyone thinks the Ensoniq DOC works deleted] Okay, hotshots, I was just looking through my "Apple IIgs Technical Reference Manual" published by McGraw-Hill and I found some stuff about the DOC. Anything in {} is my comment. It says, I quote: "Control Register. These registers control the channel assignment, oscil- lator mode, and halt bit for each oscillator in the form of a bit array." (page 349, table 14-1) "[Control register bit meaning table] Bit Use 0 Halt bit. Set when an oscillator has been halted either by the DOC or otherwise. 1-2 Mode. The value in these two bits sets the oscillating mode as follows: 0 Free Run - Oscillator runs in a continuous loop, repeating the waveform until halted or until there is a 0 in the waveform table. 1 One Shot - Oscillator moves through the waveform table once and then Halts. 2 Sync/AM - If lower oscillator is odd-numbered, it is used to amplitude Modulate the even oscillator. {as in waveform with an envelope} If lower oscillator is even, the higher oscillator syncs to the lower one. {what would this be for?} 3 Swap - Uses a pair of oscillators (lower even and upper odd) in which the two oscillators swap off waveforms. {1 for attack, 1 for decay} 3 Interrupt enable. If set, interrupt passed to the oscillator interrupt register when the oscillator completes the cycle. 4 Set to route output to channel 0 of an external analog multiplexer. 5 Set to route output to channel 1 of an external analog multiplexer. 6 Set to route output to channel 2 of an external analog multiplexer. 7 Set to route output to channel 3 of an external analog multiplexer." (page 350, table 14-2) It also says on page 335, in the fourth paragraph down from the top of the page that: "Many of the Sound Manager routines refer to generators. A generator is a pair (sometimes called a swap pair) of oscillators in Swap mode." 'Nuff said on that subject. I also found something bizzarre sounding on page 351, table 14-3. It says: "bit 6 Extend the addressing range of the DOC with address range beginning at 65536 if bit is 1." Does this mean Apple expects to eventually make a 128K sound RAM? Another thing, on a different subject. It says on page 353 that the sound output of the GS is fed to, among other places, "The sound line in the RGB output connector. (Capable of driving a 600-ohm load)" Anyone made use of this yet? Is it stereo or mono? (with that singular 'line', it sound like it's Monophonic. Can anyone confirm or deny this?) -Thanx, -The Silver Dragon. (Just a GS user, not a GS wizard) -- ******************************* }>=:) (dragon smiley) ********************* * _____ The Silver Dragon, G. Minette * "A sunrise is a beautiful * * (_|_ \ Pern Fan Extraordinaire * thing to see...before going * * __|_)_/ gminette@polyslo.CalPoly.EDU * to bed!!" - Me. (6:45am.) *