Return-Path: Received: from gs13.sp.cs.cmu.edu by K.GP.CS.CMU.EDU id aa20196; 26 Jan 93 1:53:32 EST Received: from gs13.sp.cs.cmu.edu by GS13.SP.CS.CMU.EDU id aa10259; 26 Jan 93 1:52:49 EST From: Darrell.Kindred@CMU.EDU To: bovik@CS.CMU.EDU Subject: Machines for SLIP X Terminal Date: Tue, 26 Jan 93 01:52:34 EST Message-ID: <10257.728031154@GS13.SP.CS.CMU.EDU> Sender: Darrell_Kindred@GS13.SP.CS.CMU.EDU Dr. B: Suggestions for using X-Windows/SLIP from home... ------- Forwarded Message Date: Thu, 21 Jan 93 17:07:00 EST From: Dean.Pomerleau@POMERLEA.BOLTZ.CS.CMU.EDU Subject: Summary: Machines for SLIP X Terminal Newsgroups: cmu.cs.unix.forum Organization: School of Computer Science, Carnegie Mellon First off thanks to the people who responded, including Jonathan Hardwick, Mike Blackwell, Jon Webb, Ricky Houghton. I've included the mail each of these people sent me, since they include some very helpful technical details. A few bottom line observations/suggestions I got from these people replies: 1) You can run both X-Windows and SLIP using either a Mac or a high-end PC, or you can use an old workstation as an X terminal. 2) For the Mac, the computer store sells MacX and MacSLIP for $10 each. You want to get as big/high resolution screen as you can afford, particularly for the Mac, since X normally expects a pretty big screen. Also, there may be some problem with connecting to a Mach machine through MacX (see Jon Webb's message). 3) For the PC, you can get a free version of unix off the net and run free versions of X and SLIP, or you can buy a PC X server and SLIP that run under MSDOS. 4) One problem with the current implementation of SLIP on the CS front end is that it doesn't support compressed slip (CSLIP). As a result, packets have large (~40 byte) headers and this can REALLY slow communication down. The Annex servers support CSLIP, and CS is supposed to soon also. Again, thank for all the help. - --Dean (messages follow) - -------------------------------------------------------------------------- To: Dean.Pomerleau@POMERLEA.BOLTZ.CS.CMU.EDU Subject: Re: Machine for SLIP X Terminal? Cc: Bcc: >Date: Sun, 17 Jan 93 18:48:51 EST From: jch@GS69.SP.CS.CMU.EDU Sender: jch@GS69.SP.CS.CMU.EDU In article <727310149/pomerlea@POMERLEA.BOLTZ.CS.CMU.EDU> you write: > I would like to have a computing environment at home that looks as much > like my normal environment as possible. I don't necessarily want to do > any heavy computation on the machine at home, but I would like the > windowing system, editing facilities (e.g. X-window gnu-emacs), access > to multiple machines etc. to be similar to my workstation at CMU. This is certainly possible; I'm writing this e-mail on a Sun3/50 at home, connected via a CSLIP link over a 19.2kbps DOV modem to my workstation at school. I'm effectively using the Sun3 as a dumb X terminal. > What I'm thinking of buying is either a PC or a Mac, and running X > windows and SLIP over the 9600 baud modem I have (or getting MCN). > Does anyone have any experience with this kind of setup? Are there > reasonable versions of X for the PC or Mac? Similarly, are there good > versions of SLIP? I've not been following very closely, but there has been a rush of DOS-based PC X servers announced by various companies. There are also some commercially produced SLIP implementations. On the freeware side, there are several different Unix's available off the net for 386 PC's, together with good X implementations. I'm not sure of the status of SLIP for PC-based Unix's; you should check out the relevant newsgroups (grep for "linux" and "386bsd" to start off with). MacSLIP is definitely available from the Computer Store; check out the Andrew bboard org.acs.netdev.slip (or something like that) for discussion about Andrew-side SLIP. Undergrads are using it from all sorts of weird and wonderful machines in their dorm rooms, so someone somewhere has probably done just what you're contemplating. > How effective is SLIP at providing multiple telnet > windows simultaneously over a 9600 baud modem (with compression)? Not sure about 9600, but anything tty-based is fine at 19200. Compression will increase the latency of the link, and introduce some "jerkiness"; this may or may not affect interactive response, so it's probably best to talk to someone who's done this before (Paul Parker is the resident SLIP expert in SCS). One thing to make sure of is that you get Compressed SLIP (CSLIP). This compresses TCP packet headers down from 40 bytes to around 3 or so. The difference in interactive use is VERY significant, especially if you're doing anything X-based rather than tty-based, since X applications tend to use lots of small TCP packets. For example, gnu-emacs in X mode exchanges something like 8 TCP packets with the X server *per key pressed*. These packets are basically just header + 1 byte, so we're talking 8 * (3+1) = 32 bytes = 16ms per keypress in CSLIP vs 8 * (32+1) = 264 bytes = 170ms per keypress in SLIP, at 19.2kbps. When you're limited to typing ~6 characters per second, it really hurts... Note that CSLIP is currently only available on the Andrew-side SLIP servers. It's due on the SCS servers "real soon now". In the meantime, I put up with an Andrew IP address and slight extra latency simply because CSLIP is such a big win. > Are there other alternatives besides a PC or Mac? I've thought of an > X-terminal, but they don't seem to be any cheaper than PCs or Macs, and > they are obviously less useful as a stand alone machine. Second-hand Sun3's! From an Andrew post, I think someone has also got CSLIP working via a 14.4 modem from an old IBM RT. > With a PC or Mac with SLIP and X, would I have to run a different > operating system to get access to commands like telnet etc. or is that > handled by SLIP? Commercial DOS-based products do the whole TCP/IP stack, and include their own version of ftp, telnet, finger, etc etc. The 386 freeware approach sidesteps the whole issue by using Unix. Not sure about the Mac. > If I got a 486 machine, could I run Mach on it? > Would I want to, if all I want to do is open multiple windows to other > machines and fire up gnu-emacs etc? SLIP is available under Mach (at least, the SCS-side Mach). However, it's also something of a memory pig. You might want to sound out the Andrew undergrads on this one. My overall impression is that, given a PC, you either go the DOS-based route and pay big bucks for an X server and a TCP/IP stack, or you roll your sleeves up, go the Unix-based freeware route, and get everything for free. Finally if I were to be in the same situation again (viz, having $1000 to spend to get an X terminal at home), I'd: - buy a cheap clone 386 or 486 (since they're now commodity items, and are trivial to repair or upgrade). - get linux or 386bsd off the net, ditto X server and CSLIP implementation (since they're all free, and being continuously improved) - buy a v32bis 14.4 modem with v42bis compression. Only Andrew currently supports connections at 14.4, but SCS should follow soon enough. I'd go for a modem and second phone line rather than MCN on the grounds of cost, since the outlay for a fast modem has now dropped to below that of the DOV modem for MCN, and hence the important thing is the line cost ($25/month for MCN, $10-15/month for a second phone line). - if I had the extra cash to spend, a dying need to send/receive faxes on the modem as well, or other uses for the PC at home, I'd go the DOS-based route. As it is, I'm going to ditch the MCN link and buy a 14.4 modem when the next MCN bill comes due. I'll keep the Sun3 until it dies of old age... Hope this helps, Jonathan H. - -------------------------------------------------------------------------- >Date: Mon, 18 Jan 93 10:56:45 EST From: Mike Blackwell To: Dean.Pomerleau@POMERLEA.BOLTZ.CS.CMU.EDU Subject: Re: Machine for SLIP X Terminal? Dean - I run MacX on a Mac at home, with SLIP through a 14.4K modem. I run the normal Mac OS, MacX is just another application. It works fine, but here are a couple of notes: It's slow. X has lots of network traffic updating all of the graphics, etc. In general, you want to run things locally if you can. Gemacs is no problem, but running FrameMaker remotely is painful at best. So get the Mac version of FM - the binary files are compatible. Things should get a little better when the CS Cisco servers start supporting compressed SLIP headers in a few months, but not a lot. Running Telnet directly has better performance than running an xterm (of course you can do both at the same time). I generally have a couple of telnet windows open, and MacX in the background to handle any X apps I might need to run (Calendar Manager, rolo, Xman, etc). If you're transferring files back and forth, check out the Fetch program - an FTP client with a nice Mac user interface. You definitely need a big screen. I have the standard 13" 72 dpi color screen, and it's just barely big enough to get anything done. Most X apps assume a much bigger screen. Get at least a 16", 19" would be ideal (even black and white). All of the software you need to get started is either cheap or free. CMU has site licesnses for MacX and MacSLIP, both available for $10 each at the computer store. SCS can give you a copy of the Mac FrameMaker. Let me know if you have any other questions. -m- - -------------------------------------------------------------------------- From: Jon Webb >Date: Tue, 19 Jan 93 01:26:39 EST To: Dean.Pomerleau@POMERLEA.BOLTZ.CS.CMU.EDU Subject: Machine for SLIP X Terminal? Dean I'm trying to do this as well, so I can tell you where I've gotten so far. I have a Sun at home which I connect to CMU over MCN. It works well, of course, in maintaining the same environment; I have SLIP running so I open xterm windows, gnu-emacs, etc, and use FTP to transfer files if I need to do that. But I'm not really happy with this environment. First, maintaining compatibility over the long term is a pain; one of these days I'm going to have to take my Sun box in to get it upgraded to Framemaker 3.0, for example. (By the way, I'm running Sun OS not Mach; seems to work better, from what I've heard). Second, I don't like being tied down to one room for using my Sun at home much. Third, I switch to a different environment (I have a PowerBook now) when I go on the road. So I'm trying to switch to using a PowerBook as my home environment. Right away I noticed one improvement: I get 1.92KBaud instead of just 9.6K. The Mac is better at the serial stuff for some reason. I've purchased MacSlip and MacX and have run them but haven't been able to make a connection yet so I can't say much about performance. It turns out that the protocol MacX uses requires you connect to a SunOS or Macintosh machine, not a Mach machine, I guess because facilities turned it off for Mach. Actually, in the long run, I think it makes sense to move to a Macintosh-based environment. This Unix stuff is becoming increasingly marginal. Of course, PCs are even more mainstream. But if I were you I'd be thinking about how I can start building a bridge from Unix to a mainstream computing environment. One way to do that is to start using a PowerBook from home. - -- J - -------------------------------------------------------------------------- >Date: Tue, 19 Jan 1993 10:58:06 -0500 (EST) From: Ricky Houghton To: Dean.Pomerleau@POMERLEA.BOLTZ.CS.CMU.EDU Subject: Re: Machine for SLIP X Terminal? I used to run X via a slip connection from my house on an Apollo/HP. If you want to run things like emacs, it's best to run emacs in TTY mode via a telnet session, the over head seems much less. X via slip isn't that bad, maybe running xv to view a couple large gifs, but bearable. If I had the option, I'd consider a 486 with fast disk, a bit of memory and a high speed display adapter and run MACH. Once CMU upgrades the AFS servers to 3.0, you'll be able to run AFS from home. If you have a large enough local cache, AFS at home can be great. (You can NFS from home right now.) If you consider a DOS or MAC operating system running an X emulator, I would make sure to see the X emulation via slip before purchase. My Apollo/HP does X rather well, slip and X together results in a big performance hit, though still usable. my $.02. Ricky btw, if you consider getting a 486, make sure you get the higher speed UART. The newer UARTs uses less CPU to perform the serial I/O. ========================== From: jch+@cs.cmu.edu (Jonathan Hardwick) Subject: Re: Summary: Machines for SLIP X Terminal Just a follow-up note to anyone sharing a single phone line with other hungry grad students, or with kids who want an evening with /usr/misc/.games/bin : You Don't Need X To Justify SLIP. Drag that old PC/Concept out of the basement, stick it on the second serial port of your main SLIP machine as a dumb terminal, and voila, instant network-sharing. Multiple telnet sessions co-exist very happily on a single line, probably because the times when you actually need the full bandwidth of the SLIP link (full-screen redraws, FTP transfers) are few and far between, so two people can happily read news/edit code and never notice the difference. Of course, if you both boot up some bandwidth-hungry X application, it'll start hurting. One other thing I forgot to mention in my reply to Dean : X11R6 should include support for low-bandwidth X, based on NCD's XRemote protocol that knows how to compress X. Jonathan H.