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Newsgroups: comp.unix.bsd Path: sserve!manuel.anu.edu.au!munnari.oz.au!spool.mu.edu!uunet!mcsun!chsun!hslrswi!aut!nbladt From: nbladt@autelca.ascom.ch (Norbert Bladt) Subject: Re: best lp drivers? Message-ID: <1992Nov2.093110.12375@autelca.ascom.ch> Organization: Ascom Autelca AG, Guemligen, Switzerland References: <1992Oct31.064801.5423@ntuix.ntu.ac.sg> Date: Mon, 2 Nov 1992 09:31:10 GMT Lines: 55 eoahmad@ntuix.ntu.ac.sg (Othman Ahmad) writes: >I am considering lp drivers from so many people, I do not know which onw >to install. I have the same question. However, read on. >The ones that I manage to pick are: >1) Wolfgang Stanglmeier (without interrupts) >2) Tibor Sasheqyi ( he said trivial) >3) Jim Bevier >I'm considering 1) because of performance reasons but not sure if anyone else >had installed it. Performance will degrade if you are not using interrupts, but poll instead. So you won't gain any performance in using this driver. However, there is, at least, one very good reason for this driver: Not all PC interface boards support a clean interrupt interface to the parallel port, i.e. interrupts are unreliable (if at all generated) for parallel ports. >2 & 3 are different in the recommended device numbers, 14 vs 15 ? If that's the only difference, they are the same ! This is configurable, i.e. it depends on a table in the kernel (cdevsw) and the numbers of entries in it. If you have an entry at (let's say) index 14, already, the major device number for a new driver must be 15. If you have an entry at 15 this number must be 16, and so on. Always the next number in the table. Unfortunately, there is no agreement on the use of those numbers, yet. I think, your choice will depend on your specific board. It might even work with the supplied lp driver (I think there is one) ! If your board supports interrupts reliably, that is. I would try this, first, before adding other drivers to my system. I am very conservative in this sense. Just replace the stock-software with something else only, if the stock-software doesn't work and you can't get it to work with a few patches. Hope this helps (I won't give a lesson on the cdevsw table, the major and minor device numbers and so on, here), Norbert. P.S. Now I know why you would like mtools to work with CD-ROM's. You must learn a lot to know some internals of any UNIX system, first, to hack the code to suit your needs. And, if you don't know where to do it you might be doing it totally wrong. BTW: There are some problems with MS-DOS and CD-ROM files. Unfortunately :-) some files on one or the other CD-ROM don't follow this stupid 8.3 filename rule of MS-DOS. What about this and mtools (I know, you could hack this, too) ? -- Norbert Bladt, Ascom Autelca AG, Worbstr. 201, CH-3073 Guemligen, Switzerland Phone: +41 31 999 65 52 FAX: +41 31 999 65 44 Mail: nbladt@autelca.ascom.ch UUCP: ..!uunet!mcsun!chsun!hslrswi!aut!nbladt