Date: Wed, 6 Mar 1996 09:48:18 +0100 (MET) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-scsi@freebsd.org Cc: jkh@time.cdrom.com (Jordan K. Hubbard) Subject: Re: HP 4080i as both CD and WORM? Message-ID: <199603060848.JAA10424@uriah.heep.sax.de> In-Reply-To: <414.826088711@time.cdrom.com> from "Jordan K. Hubbard" at Mar 5, 96 09:05:11 pm
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As Jordan K. Hubbard wrote: [Scope widened to freebsd-scsi without Jordan's permission, hope he wouldn't mind. :) ] > Compliments again on the WORM support - this is working really well! Well, it still suffers from a few idiosyncracsies and design flaws. The most annoying one is the blatant use of UNIT ATTENTIONs in these drives, which causes four messages at boot time, and still required me to insert an extra ``scsi -f /dev/rworm0.ctl -c "0 0 0 0 0 0"'' into the script i'm using to burn CD-R's. (This is a harmless TEST UNIT READY command, only to catch the UA condition.) It misses the code for a few common burners as well, the most frequently asked question is about the Yamaha devices. Jordan, could you bug Yamaha to release their SCSI reference manual to us, even though we cannot promise them any sales figures and other $%!@? It misses code for ``disk at once'', and my Plasmon doesn't even seem to support this. I wonder whether it's possible to simulate this by reserving all desired tracks with their projected size, and then writing them sequentially. Our CD-ROM driver misses any functionality to access the different sessions you can burn. It always only accesses the first one, so you gotta waste much space. (Example: a plain FreeBSD SNAP without ports is ~ 150 MB. You could put four of them onto one CD-R.) The CD-ROM driver does also seem to miss the audio part. This might or might not become tricky, in particular given the weird block size of audio tracks (2352 bytes). > It'd still be kind of nice, however, to be able to use it as a CDROM > when the occasion dictated. I know someone who's buying it as a > replacement for his existing CDROM, in fact, and I can bet which > question he's going to ask me first.. :-) You've been in the scsiconf > code - any quick ideas? I notice that a match prevents further > scanning as another type of scsi device, so you can't just add a CD > entry in (I tried :-). The worm driver is very special in this respect. In theory, it should already be able to read the data from the raw device, but i know that it doesn't. Once this is working, somebody needs to create also the `bdevsw' entries -- not a big deal. For a more advanced operation, the driver needs to inherit all the functionality of the CD-ROM driver. It is a very special case, since the CD-Rs can be considered a ``super-class'' of CD-ROMs. We could either clone the CD-ROM driver, or violate the layering and jump directly into the CD-ROM functions. Or we invent something new, where the common part will be extracted into a device-independant CD-ROM driver, with the `cd' and `worm' drivers providing the actual framwork to access its functions. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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