Article View: comp.terminals.tty5620
Article #41Re: Layers question.
From: John M. Twilley
Date: Sun, 22 Nov 1992 21:02
Date: Sun, 22 Nov 1992 21:02
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2539 bytes
In article <19392@smoke.brl.mil> gwyn@smoke.brl.mil (Doug Gwyn) writes: >In article <+lz1!a@rpi.edu> nautilus@lachesis.acm.rpi.edu (John M. Twilley) writes: >>I was wondering why layers spends so little time transferring data from >>host to terminal. I hooked up a 9600 bps modem, and got no better >>throughput than I did at 2400. Help? > >If you're using a pty-based layers rather than an xt- or STREAMS-based >version, the host is being eaten alive by context-switch overhead. Nope -- xt-based. Would one of those switches (-h?) help if I put STREAMS in? > >Packet size is also rather small so some of the link bandwidth is >consumed by packet framing overhead. I think the 730 supports a >larger packet size but the host "layers" process might not be using it. I can't seem to get the packet size to grow -- I don't think the 5620 supports it. > >In the resident terminal emulator mode, the terminal does a lot of work >per character and so its effective "glass tty" speed is less than one >would imagine. This is especially obvious when using Dave Prosser's >(otherwise very nice) "myx" on a 5620. Where can I find this "myx"? Is it vailable from FTP? > >I can see a substantial difference between 9600bps and 19200bps links >between my 630 and a directly-connected Sun-3/50 host. > >Note that so-called "9600bps" modems operated over voice-grade phone >lines, if they depend on statistical data compression, will have less >effective throughput than that when transmitting random binary data >instead of highly patterned data. Also, I often call out from my DMD to other computers through my 3B2. Does anyone out there have a good terminal program written todo the following? - do as much as possible on the DMD's processor, excepting file xfer - provide VTx00 emulation (ancorrectly resize the windo, ifnecesarry) If anyone has any leads, please let me know ..... Jack. -- John M. Twilley | It's only premarital sex if nautilus@acm.rpi.edu | you're going to get married. twilley@dewey.nusc.navy.mil | --anonymous
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Newsgroups: comp.terminals.tty5620 Path: arc1-ca.pugleaf.net!sparky!uunet!cs.utexas.edu!zaphod.mps.ohio-state.edu!rpi!lachesis.acm.rpi.edu!nautilus From: nautilus@lachesis.acm.rpi.edu (John M. Twilley) Subject: Re: Layers question. Message-ID: <#-31+5d@rpi.edu> Nntp-Posting-Host: lachesis.acm.rpi.edu Organization: The Voice of Fate References: <+lz1!a@rpi.edu> <19392@smoke.brl.mil> Date: Sun, 22 Nov 1992 21:02:46 GMT Lines: 46