Making an X Terminal from a PC

PSwiss writes: "I recently wrote an article for Linux Gazette on how to make an X Terminal from an old PC (486s work great). It's a neat application of Linux and would make a good project for some weekend." This is a nice step-by-step guide ... we posted a similar project not too long ago, about diskless linux kiosks.

Comments

Nice article...but what about adding ssh?

[torpor]

Be nice if details on setting up an ssh link between the two were included so that:

1. The X link is compressed.
2. The X link is encrypted.

That way we'd have the ultimate fast/secure connection, and it'd be a lot handier for folks that want to use their X Terminal from anywhere on the 'net...

Generally, a good article though. Note the age of the author - good stuff!

Re:Nice article...but what about adding ssh?

[Jason Earl]

I did something similar with a 486/33 (20M ram) and a Cyrix P150+ (64M ram) without ssh, and it worked great. It wasn't slow at all. In fact, it was so much like actually sitting down at the Cyrix that it was spooky. My guess is that the latency added by compressing (and encrypting) your session killed your performance. Compression really only helps over low bandwidth links. If you aren't maxing out your pipe, you shouldn't be compressing your traffic.

I don't suppose you ran top on your 486 to see how badly your processor was swamped. My 486 would get to 100% processor utilization just running X. With the compression and encryption my guess is that you just asked to much of your client.

Re:Nice article...but what about adding ssh?

[salty_oz]

Over a local Ethernet LAN (which I assume this was done on) using SSH compression would probably slow things down.

There's a trade off between network latency and compression latency. The general rule we use around here is if the link speed is over a few Mbps then compression ain't worth it.

Re:Nice article...but what about adding ssh?

[Saint Aardvark]

Hm...here's my experience w/that very setup:

Had a 486dx33, 16mb of ram, don't rem. the video card but it was 2mb of ram; ssh'ing into a 90 MHz pentium, 48mb of ram. The 486 was used by my wife (just got married, and boy does that word sound weird) to run Netscape, mainly, w/IceWM as a nice low-end WM.

What we found was that it was pretty slow, actually. We'd done a full install of Debian onto the 486, so we didn't have to use NFS or bootp or the like. I'd say 75% of the time she was the only one running X on my computer (the 90 MHz Pentium), so it wasn't like my underpowered box was trying to run two servers/clients (can't rem. the proper terminology right now) at the same time. And the two computers were connected w/10Mb/s Ethernet cables. But...

Well, we found it was slow: slow to display new pages (ADSL connection at home, so bandwidth wasn't the problem), slow to display new pages, and slow in general. I would listen to my computer run while she loaded pages, and there wasn't a lot of swapping, so I don't think it was that. If I had to guess at the bottleneck I would say it was running SSH on a 486 (one other thing: we were running ssh -c blowfish, so the cipher used would be less processor intensive).

That said, can anyone else offer any insight here?

Re:Nice article...but what about adding ssh?

[Saint Aardvark]

If your attacker is sniffing packets on your local area network you have bigger problems than the fact that they might eavesdrop on your X session.

Excellent point. However -- and this is a broader point than merely this article -- I wanted to learn how to do this sort of thing. There's a constant urging in Unix circles not to reinvent the wheel -- yet how do you ever learn to do something other than by trying to reinvent the wheel?

xterminals with Red Hat

[FiDooDa]

I liked this better: www.solucorp.qc.ca/xterminals/
especially the nice setup.sh script.

My experience with X terminals

[quartz]

I used this kind of setup in a project at some company I worked for one time, to support the warehouse management application I had written (*please* don't ask why a warehouse management app needed X... thank you). Beefed-up server (multi-processor, RAID, the works) and 10 diskless terminals w/ remote boot and root via NFS. And RedHat Linux 6.2.

Worked like a charm. The terminals were all cheapo 133 MHz AMD's with S3 graphics cards, worthless for pretty much anything else. Did so well as X terminals, they are still using them today. Of course, they were all on 100 Mb Ethernet though...

Never works out

[guisar]

I did this with Linux 1.X- hooked a bunch of PCs up to be X terminals for our SGI. Worked swimmingly and really cut down my workload. Everything was great until some dork in Network operations found out we were using X11 across the "enterprise network". I learned something very important during the week following this revelation- X terminals are like Unix- they suffer from a bad name.

Cook up something like the SunRay- give it a funky LCD display (not included) and tie it to some proprietary server software and everyone thinks it's great. Do the same thing with X and "it's a bandwidth hog", "user's will never be able to figure it out" and on and on.

Non- Unix users don't give a damn about the power of X. They don't get why it's useful or appreciate the advantages. They like things they have to pay extra for or tie them down to a specific architecture- we in turn don't understand them or this attitude.

So, I did this in my house. My Cyrix 200MHZ became an X terminal for my kids to play tuxracer and cruise the net. Just don't tell them what's going on. Sell it at work the same way- don't say squat- just do it and spend the extra money on cool toys.

Re:Never works out

[sigwinch]

Everything was great until some dork in Network operations found out we were using X11 across the "enterprise network". I learned something very important during the week following this revelation- X terminals are like Unix- they suffer from a bad name.

X terminals are like telnet: less than total security competence, or a momentary brain fart, and a sniffer gets your passwords. If you're a sysadmin, the organization is screwed. Random people doing remote logins gives me the heeby-jeebies.

Non- Unix users don't give a damn about the power of X. They don't get why it's useful or appreciate the advantages.

They don't know about the power of X. All they've ever seen is Microsoft Windows on the console. Let them play with VNC or Terminal Server, though, and you'll make them true believers.

I'm using this in concept two places

[autechre]

The first is at the Retriever Weekly, the college newspaper for UMBC. We have 3 P-90s w/ 16M RAM and S3 virge cards running as X-terminals from a P-II 300 w/ 128M RAM. It works great; they run KDE, StarOffice, Mozilla, etc. with no troubles. The same machines were unusable with Win98 on them.

The second is in a volunteer computer lab in Baltimore city at the Agape house (http://linux.umbc.edu/gits). Most of the machines there are 486s with 16M RAM, so they use IceWM and work just fine from a dual Celeron 400 w/ 256M RAM. Jeff Covey, the main person behind this lab, has set them up to netboot using the Linux Terminal Server Project (http://www.ltsp.org). The difference in noise level between 8 486s running with and without hard drives is very noticable! I'm hoping to set up the machines at the newspaper this way soon.


Sotto la panca, la capra crepa

X terms all the way

[geoffrey crawford]

I'm posting this on a 486DX2/66 with 16 megs of RAM and a 1MB VESA video card...

It runs Xfree 4.. and uses esound for sound across the network

These things works great. My sister uses one, and I have a second so I can kill X when it locks up my good computer (which the X terms run their apps on)

If you can stomach 640x480 at 8bit... a 386 will do that fine too!

Beauty of these is the sound level... jam the fan in your 486's powersupply, and it's 100% silent!

Using config files based on MAC adresses works really great too. The machine boots, and checks if it has an existing X config file named as it's MAC address. If not, it runs xf86config, gets you to set the initial settings, and saves it for future use.

A p150 with a good video card, even on 10Mbit feels like the local machine. It's really nice.

Linux is way overkill

[Tech187]

Back in the day when 3/486 machines were more expensive and there were tons of 286 boxes readily at hand, I used to experiment a lot with TCP/IP networking using 286 boxes running DOS with Microsoft's LanManager Client (still available for free at Microsoft, btw.) connecting to Samba shares and telnetting into my cherished Linux (1.0 and 1.2 kernel) box from all around the house. 3C501 10base2 ethernet cards (eeek!) were $2.50 a pound at the local surplus store and life was grand.

It seemed to me at the time that what was really needed was a good, free X Terminal package to run on older boxes themselves not capable of running Linux.

These days, '486 hardware is the 'low end' and it might not be as important as it once was to use the really slow boxes (they're a waste of electricity to leave on, some would say) but it seems like ridiculous overkill to run a Linux kernel on something as simple as an X Terminal. The services running can be cut way back, etc. but it's still overkill for the machine to need a processor with Memory management (386 or greater) when even simpler hardware should work fine.

Nothing beats my 31337 NCD :)

[ikekrull]

Theres nothing quite like the horror of running X on a 2MB M68000-powered black & white NCD X Terminal.

the 19" monochrome monitor looks cool in an old-skool way, but its unbelieveably slow.

After i bought this machine, i was hit with the shocking realisation that i am indeed a hopeless *NIX geek, and there is no going back.

Do it on your own

[joq]

You can download STunnel and do this on your own, it's definitely not a hard task to do.

A good use...

[Karpe]

...for these X terminals would be to be put in public schools here in Brazil. Some public schools don't have even a single PC. If we could make people donate their old hardware to these schools, and buy a powerfull machine as the server, we could make some computer labs, and better, introduce young people to GNU/Linux. Here in my state, in the south of Brazil, public schools are already using preferentialy GNU/Linux, but that's another story.

But the people who should know how to do this are the responsibles for the schools' machines, most of the slashdot crowd had already thought and learned how to do that.

The bad thing is that most 486 didn't have good videocards, and the performance (no XAA?) of XFree86 with ISA cards is not great, even as an X-terminal only. I remember the performance of XFree with my Trident VLB, which sucked, even for that time. The only nice card in a 486 with XFree I used was a S3 VLB, but those are hard to find, even used, of course.

It would also be great if those IDE "disks" based on flash memory were cheaper. We could make very silent, self-sufficient (no network or floppy boot) machines. The devices don't even need a large memory, or "disk". Good to make some "NCs" (fancy name for something that exists for at least 10 years in the X world :) )

The more things change...

[SumDeusExMachina]

Well, I don't know about some of you people (I heard somewhere that the average age of the Slashdot poster is around 15), but I remeber back in the day when we had to use terminals to use a computer at all. Yup, those were the days allright. Worrying about getting your processes killed for taking up too much CPU time, running up massive bills for computer time, etc.

I thought that we had gotten away from this by the early '90s when PCs became common and powerful enough that you could operate relatively comfortably without the support of some big iron. After all, wasn't the whole big-iron-to-desktop transition about self-empowerment? I thought so, because I didn't have to worry about pissing off some sysop when I compiled my newest Linux kernel on my 386 with 8 megs of RAM.

But now we have this crap about creating X terminals now. Don't we learn anything? We have all immensely enjoyed the personal freedom accorded to us by having enough local processing power to get the job done, no matter how many times the remote server crashes and burns. Besides, I have better ways to allocate my network's bandwidth than with a ton of X packets. Like, say, playing Quake III or browsing the web, or transfering files to my Windows 98 box from my NT server.

Plus, we are confronted with the fact that 486s probably won't have very nice video cards to begin with, so you can pretty much kiss a decent-looking display goodbye.