Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!snorkelwacker!ai-lab!life!entropy From: entropy@mole.ai.mit.edu (Nick Castellano) Newsgroups: comp.sys.atari.st.tech Subject: Re: spl or snd file format Message-ID: Date: 17 Oct 90 08:22:43 GMT References: <8928@cognos.UUCP> <1990Oct16.213405.23309@wam.umd.edu> Sender: news@ai.mit.edu Organization: not much Lines: 24 In-reply-to: dmb@wam.umd.edu's message of 16 Oct 90 21:34:05 GMT In article <1990Oct16.213405.23309@wam.umd.edu> dmb@wam.umd.edu (David M. Baggett) writes: +2.5V. To convert from unsigned to signed format you simply have to subtract 128 from each sample. To go the other way, you add. (Sounds simple, but try to figure it out by looking at the data files!) Incidentally, the Hippo digitizer uses signed samples. The "standard" ST format is 8-bit unsigned. To convert between them, get a copy of "convert.arc" from atari.archive.umich.edu:/atari/newitems/ The program hippo2st.ttp will convert 8bit signed to 8bit unsigned. (Guess what st2hippo.ttp does....) Why are 2 programs needed? Isn't adding/subtracting 128 the same thing, modulo 256? They should both equate to XOR 128, no? nick -- | | | ncastellano@{eagle.wesleyan.edu, wesleyan.bitnet} | | | entropy@ai.mit.edu / | \ Sinkhole!dEADHEAd[@mast.citadel.moundst.mn.org] (call 203-873-8518) / | \ snikt!entropy