Re: Sound Input on IIGS From: dempson@actrix.gen.nz (David Empson) Reply to: David Empson Date: Tue, 06 Aug 1996 01:02:22 +1200 Organization: Empsoft Newsgroups: comp.sys.apple2 Followup to: newsgroup(s) References: <4tsc5k$r7l@news.vanderbilt.edu> <3AUG199606073181@vax2.concordia.ca> <4u3tos$ian@news.vanderbilt.edu> In article <4u3tos$ian@news.vanderbilt.edu>, lesherjt@vuse.vanderbilt.edu (Tilghman Lesher) wrote: >Mitchell Spector (spec@vax2.concordia.ca) wrote: >: In article lesherjt@vuse.vanderbilt.edu (John Lesher) writes... >: > >: > How can I get the IIGS to sample sound? When I had >: >my //e, I had this nifty little program to sample sound via >: >the cassette port, but the IIGS has no cassette port. Is >: >there a simple method? Or must I buy a peripheral card? > >[snip] > >: As I mention above, sound sampling is built-in to the chip (ADC), >: but Apple didn't add any conventional way to plug in your sound source. >: They did however provide a set of molex I/O pins. You basically have > >[snip] > >Where on the motherboard are these pins and (if > 2) what are the >pinouts? It is the 7-pin molex connector in the lower right corner of the motherboard, next to the Ensoniq. All stereo cards plug into this connector. Most of the pins are used for sound output and associated demultiplexing. Pin 1 is the sound input and pin 2 is analog ground. (Pin 1 is the one closest to the back of the computer, right next to the legend "J25" on the ROM 1 motherboard.) The sound input expects a signal which has a maximum range of 2.5V peak to peak. The input impedance is 3000 ohms. I'm not all that clear on audio impedances and voltages, so I'm not sure if it is safe to connect anything directly to this pin. It may be necessary to use a simple amplifier circuit to handle impedance matching. Can anyone elaborate on this? -- David Empson dempson@actrix.gen.nz Snail Mail: P.O. Box 27-103, Wellington, New Zealand