Date: Thu, 7 Mar 1996 09:54:15 +1300 From: "Dave Cowl" <Dave_Cowl@trimble.co.nz> To: freebsd-scsi@FreeBSD.org Subject: Re: HP 4080i as both CD and WORM? Message-ID: <418863A4F4E@trimble.co.nz>
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>From Jrodan and Joerg: ) > It misses code for ``disk at once'', and my Plasmon doesn't even seem ) ) I'm afraid that I don't quite know what is meant here? In a standard CD write, the track(s) are written and then afterward the lead in (which contains the TOC) and the lead out are written. This way, the TOC is well known BEFORE the TOC is actually written into the lead in, because the tracks are already written. The problem with this approach is that mastering machines for CD pressing do not like the 'gaps' between the post written lead in and the first track. They read errors and complain. Disc at Once requires that the TOC is formed pre-write. Then the Lead in, tracks and lead out is written in 1 hit. Thus, there is no gaps, errors or anything. For Disc at Once, you need to know a lot more about what you are doing before you start. Also, the machines differ greatly in approach - the Yamaha is apparently quite simple to programme in DAO mode - the HP and Philips drives are pretty nasty, especially if you want to do CD-XA or something. In fact, I gather that the HP firmware (and probably Philips also) is buggy for mixed mode DAO (ok for audio, except L & R get transposed). Anyways, he upshot is that with no gaps, DAO discs can be used for pressing masters. Also they can have any arrangement of tracks, gaps between tracks and index markers. I am keen to see DAO included in the WORM software. On the negative side, my internet connection sucks and I am rusty on coding. My knowledge of SCSI is almost non-existant, and I am currently busy with a potential relocation to the Bay area (6500 miles away). Anyways, with a bit of direction, I am willing to do my share. BTW, is the 4080i a new HP product, or a typo? Later... Cheers! DAve. "The large print giveth, and the small print taketh away"
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