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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!nntp.coast.net!howland.erols.net!news.mathworks.com!fu-berlin.de!irz401!orion.sax.de!uriah.heep!news From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.admin,comp.protocols.ppp,comp.unix.questions,comp.unix.bsd.freebsd.misc,comp.unix.bsd.netbsd.misc Subject: Re: Best Unix for SLIP/PPP Server- Best Reliability/Cost? Date: 19 Nov 1996 02:01:52 GMT Organization: Private BSD site, Dresden Lines: 20 Message-ID: <56r4eg$3sr@uriah.heep.sax.de> References: <56cfhc$h8b@access5.digex.net> <56d1m9$9ba@server05.icaen.uiowa.edu> <56dl8p$rje@panix2.panix.com> <56igd8$if@anorak.coverform.lan> <56l9i4$e7k@cynic.portal.ca> <56lbop$egq@nntp1.best.com> <56m28s$jpb@cynic.portal.ca> Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) NNTP-Posting-Host: localhost.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: knews 0.9.6 X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E Xref: euryale.cc.adfa.oz.au comp.unix.admin:50594 comp.protocols.ppp:15949 comp.unix.questions:91513 comp.unix.bsd.freebsd.misc:31232 comp.unix.bsd.netbsd.misc:4893 cjs@cynic.portal.ca (Curt Sampson) wrote: > > Modern multi-port serial cards will do hardware handshaking themselves > > and use FIFOs. > > And how does the data get out of the FIFOs? You've got it: polling. > No interrupts are generated. Nope. ``Tx buffer empty'' interrupts are probably as old as serial communication chips are. Of course, back in the Z80 days, it was also common to wire the SIO for DMA transfers. In this situation, the DMAC caused the interrupt once its block counter went 0. This allowed for a fairly large ``FIFO''. -- 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. ;-)