Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!overload!dillon From: dillon@overload.UUCP (Matthew Dillon) Newsgroups: comp.sys.amiga.tech Subject: Re: DNet running under Sun OS 3.5 Message-ID: Date: 28 May 90 16:23:17 GMT References: <981@tau.sm.luth.se> Lines: 48 >In article <981@tau.sm.luth.se> d88-mbe@sm.luth.se (Michael Bergman) writes: > >Now for my question: >I have read articles here (or in c.s.a.) saying that some of you use >38400 bps between Sun and Amiga using a terminal program (JRComm >I think) with little or no problems. I know it's not possible to run DNet >in more than 19200, but there are terminal programs that can and naturally >I want to run as fast as I possibly can :-) >Sz in 38400 would be *very* nice... >Can this be done under OS 3.5 or OS 4.0.3? If so, give me some arguments that I advise not to run DNet faster than 19.2KBaud on the built in serial port simply because a standard Amiga cannot receive faster without loosing data... you wind up going slower due to packet errors. That's all. Since both DNet and terminal programs use the serial.device one assumes the same problem would occur with the terminal programs. People who hack their own serial.device's (for example, to run at MIDI speeds without loss of data) can get better results but I do not know of any terminal programs that do that. And, of course, smart serial cards such as those you can plug into an A2000 can usually be run much faster. UNIX systems tend to barf on serial at high data rates. Generally, the kernel buffer (usually 256 bytes) will get full before the user task has a chance to drain it with read(), causing lost data. The problem can normally be avoided by using a 7-wire (e.g. RTS/CTS) interface which is certainly possible if you are directly connected. The only limitation with the SUN or whatever is the maximum baud rate the serial port hardware understands, and the maximum baud rate supported by the IOCTL call. -Matt > Michael Bergman Internet: d88-mbe@sm.luth.se > // Undergrad. Comp. Eng. BITNET: d88-mbe%sm.luth.se@kth.se >\X/ U of Lulea, SWEDEN ARPA: d88-mbe%sm.luth.se@ucbvax.berkeley.edu > UUCP: {uunet,mcvax}!sunic.se!sm.luth.se!d88-mbe -- Matthew Dillon uunet.uu.net!overload!dillon 891 Regal Rd. Berkeley, Ca. 94708 USA