v097pba8@ubvmsd.cc.buffalo.edu (Ken F Morton) (02/17/91)
I am interested in doing some sampling applications with my GS and I'd was wonder if someone could enlighten me. What is the max baud rate the GS can handle (probably based on the card one uses to digitize)? Also what is the resolution? Eight bit? Sixteen bit? And is it possible to sample directly to a disk? What I'd like is a CD quality sample rate that can store upwards of three minutes. Is this possible? (Definite Hard drive...) Thanks... Ken
toddpw@nntp-server.caltech.edu (Todd P. Whitesel) (02/17/91)
v097pba8@ubvmsd.cc.buffalo.edu (Ken F Morton) writes: > I am interested in doing some sampling applications with my GS and >I'd was wonder if someone could enlighten me. What is the max baud rate >the GS can handle (probably based on the card one uses to digitize)? Stereo boards currently available are lousy for this, because they use the digitizer that's built into the Ensoniq -- it's very sensitive to noise and the GS doesn't shield it nearly as well as the Mirage. The maximum sampling you can get out of the ensoniq A/D is 8 bits mono at 31 microseconds per sample (32, probably, to be safe) which translates to about 31,250 samples per second. > And is it possible to sample directly to a disk? not using the ensoniq A/D, because the CPU has to service the digitizer for every sample. You'd need a self contained digitizer that had its own buffer. I've seen Mac II programs that sample directly to disk but they don't get anywhere near CD quality. No, I take that back: you might be able to sample directly to disk IF you have a RAMfast and certain conditions can be met... mail me if you're interested, the idea I have is sick but it will probably work. > What I'd like is a CD quality sample rate that can store upwards of >three minutes. Is this possible? Again, not with the currently available boards for the GS. If you really want CD quality then you'll need a NeXT or a fairly expensive NuBus card and a Mac II. Question -- do you really NEED CD quality sampling? Todd Whitesel toddpw @ tybalt.caltech.edu
daveh@ccwf.cc.utexas.edu (David H. Huang) (02/18/91)
In article <60166@eerie.acsu.Buffalo.EDU> v097pba8@ubvmsd.cc.buffalo.edu writes: > > I am interested in doing some sampling applications with my GS and >I'd was wonder if someone could enlighten me. What is the max baud rate >the GS can handle (probably based on the card one uses to digitize)? What does baud rate have to do with digitizing (unless you're using something that sends the digitized data through the serial port, like Farallon's MacRecorder(?) for the Mac)? I guess you want to know the maximum digitizing rate a card can handle. Well... the AE Sonic Blaster card uses the Ensoniq's A/D converter which is supposed to be able to digitize in 26 cycles. With a clock rate of about 2.5MHz, you can theoretically digitize at 96000Hz, but there is some overhead. I'm pretty sure you can get 44000Hz though, although the Sonic Blaster software might not be able to do it. Note: I don't have a Sonic Blaster card, but I do know stuff about it and I do know how fast the Ensoniq can digitize, but if I made any mistakes, please correct me. >Also what is the resolution? Eight bit? Sixteen bit? And is it possible >to sample directly to a disk? What I'd like is a CD quality sample rate >that can store upwards of three minutes. Is this possible? (Definite Hard >drive...) Currently, you can only get 8 bit resolution. No program that I know of can sample directly to disk (at least not with a decent sampling rate). However, you can play sounds from disk with LongPlay, by me (plug plug :-). If you really need to digitize more than 3 minutes of sound, you could digitize in pieces and stick them together, but it's _very_ tedious and pretty difficult to edit it so you don't notice where the first part ends and the second begins. BTW, LongPlay v1.1 will be done Real Soon Now, and it has some neat features, such as support for the AE Sonic Blaster and Audio Animator file format and ability to play at different speeds. -- David Huang | Internet: daveh@ccwf.cc.utexas.edu | "Slight accidents with funny rays UUCP: ...!ut-emx!ccwf.cc.utexas.edu!daveh | can have serious consequences" America Online: DrWho29 |
daveh@ccwf.cc.utexas.edu (David H. Huang) (02/18/91)
In article <1991Feb17.034253.13536@nntp-server.caltech.edu> toddpw@nntp-server.caltech.edu (Todd P. Whitesel) writes: >the GS doesn't shield it nearly as well as the Mirage. The maximum sampling >you can get out of the ensoniq A/D is 8 bits mono at 31 microseconds per >sample (32, probably, to be safe) which translates to about 31,250 samples >per second. Why is this? The Apple IIGS technical reference says that the Ensoniq A/D can sample every 26 cycles. Adding some overhead of maybe 15 cycles, and using a clock rate of 2.5Mhz, you get 61000Hz. Is the technical reference in error, or am I making some mistake in using a clock rate of 2.5MHz? I do remember reading something about 31us in the GS hardware ref though... -- David Huang | Internet: daveh@ccwf.cc.utexas.edu | "Slight accidents with funny rays UUCP: ...!ut-emx!ccwf.cc.utexas.edu!daveh | can have serious consequences" America Online: DrWho29 |
toddpw@nntp-server.caltech.edu (Todd P. Whitesel) (02/18/91)
daveh@ccwf.cc.utexas.edu (David H. Huang) writes: >The Apple IIGS technical reference says ... every 26 cycles. >I do remember reading something about 31us in the GS hardware ref though... The hardware ref is where I got my figure. Todd Whitesel toddpw @ tybalt.caltech.edu