Re: two keyboards, two monitors, two users, one processor?
In article [EMAIL PROTECTED] you write: Jameson Burt [EMAIL PROTECTED] writes: I seek to use one computer with two full X-windows users. This would be a cheap in time/money approach for my wife and I simultaneously using Linux. It might be worthwhile finding a cheap 386 or 486 with a good graphics card. Install a minimum of programs on it, just the X server. If you run xfs on your main computer, you won't even need the fonts. You could do this with even a 200 MB hard disk, I think. You *will* need 2 network cards for this, but setting up two computers on a network under Linux is easier than some single-computer stuff. X is probably too slow over serial. Two HUNDRED meg? I know from experience that all the necessary stuff can be fit on a single 1.44 MB floppy. This included a stripped-down kernel, libc, ash, S3 X server, and the necessary tools to establish a SLIP connection over a null modem cable. Unless you have less than 8Mb of RAM, you probably won't need a swap file/partition. I didn't use init, but wrote a small shell script to do its job instead. If you don't mind a small amount of lag, it even works acceptably fast over a 115.2kbps wire! However, if I was doing this for any other purpose than proof of concept, it would hardly be worth not paying 20 pounds each for a couple of cheap network cards. It is easy to plug in two mice, dodgy to plug in two monitors, but pretty much impossible to plug in two keyboards at the moment, IMO. Apparently GGI can handle two keyboards if you have both a PS/2 keyboard and a [whatever-the-other-sort's-called] keyboard plugged in at once. -- Charles Briscoe-Smith White pages entry, with PGP key: URL:http://alethea.ukc.ac.uk/wp?95cpb4 PGP public keyprint: 74 68 AB 2E 1C 60 22 94 B8 21 2D 01 DE 66 13 E2 -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
This is exceedingly odd. As a power engineer in training I would say somebody did a really rotten job designing the power supply in one of your machines. Was there any other equipment on either of the machines's outlets? Poor power regulation aside, I don't see how a phase difference affected the serial port. I hope that in general at least this isn't a problem. I heard people say that with an RS232 connection, there might be a problem due to the differences in the ground potential of the 2 systems involved. Can you comment on this, as a power eng ? Thank you. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
On Tue, 24 Feb 1998, Wojciech Zabolotny wrote: On 24 Feb 1998, Carey Evans wrote: Britton [EMAIL PROTECTED] writes: On 23 Feb 1998, Carey Evans wrote: [snip] I think most X apps would run tolerably over a null modem cable. If I understand these gadgets right, the can operate at the speed of the serial port, which is about 120 kbps, I think. Even over ppp (33k modem) many apps function reasonably well. OK, you're probably right. I forgot how much faster a null-modem is than a 28.8K modem. However using the null modem cable one must be very carefull about power supply! Sometimes it is possible to destroy serial ports, when two computers are connected to the sockets powered from different phases. I've done it :-(. The safest solution is to power both of them right from the same socket. Wojtek Zabolotny [EMAIL PROTECTED] This is exceedingly odd. As a power engineer in training I would say somebody did a really rotten job designing the power supply in one of your machines. Was there any other equipment on either of the machines's outlets? Poor power regulation aside, I don't see how a phase difference affected the serial port. I hope that in general at least this isn't a problem. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
From: Britton [EMAIL PROTECTED] On Tue, 24 Feb 1998, Wojciech Zabolotny wrote: On 24 Feb 1998, Carey Evans wrote: ... However using the null modem cable one must be very carefull about power supply! Sometimes it is possible to destroy serial ports, when two computers are connected to the sockets powered from different phases. I've done it :-(. The safest solution is to power both of them right from the same socket. Wojtek Zabolotny [EMAIL PROTECTED] This is exceedingly odd. As a power engineer in training I would say somebody did a really rotten job designing the power supply in one of your machines. Was there any other equipment on either of the machines's outlets? Poor power regulation aside, I don't see how a phase difference affected the serial port. I hope that in general at least this isn't a problem. That sounds like a ground loop problem. Daniel -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
This discussion starts to be out of list's topic, sorry. I'll send further responses only by e-mail. If the power instalation is properly designed, it should be no problem. However I, personally, would always prefere two have an additional zero current ground wire dedicated for computers only. And there still exists a problem with voltages induced by eg. electric storms. The optoisolation circuit (not very expensive, because it is not very fast link, and for software flow control two transoptors powered from unused port lines are sufficient) is much better solution. The standard built-in serial ports, are rather delicate (Usually they are even not compatible with RS232 standard, because they may work correctly with 0V-5V logic levels). The professional RS232 boards should be safer. This problem is particularly serious, when someone wants to connect two computers using their parallel ports (and PLIP). The parallel ports are much less protected. Wojtek On Wed, 25 Feb 1998, Britton wrote: On Tue, 24 Feb 1998, Wojciech Zabolotny wrote: On 24 Feb 1998, Carey Evans wrote: Britton [EMAIL PROTECTED] writes: On 23 Feb 1998, Carey Evans wrote: [snip] I think most X apps would run tolerably over a null modem cable. If I understand these gadgets right, the can operate at the speed of the serial port, which is about 120 kbps, I think. Even over ppp (33k modem) many apps function reasonably well. OK, you're probably right. I forgot how much faster a null-modem is than a 28.8K modem. However using the null modem cable one must be very carefull about power supply! Sometimes it is possible to destroy serial ports, when two computers are connected to the sockets powered from different phases. I've done it :-(. The safest solution is to power both of them right from the same socket. Wojtek Zabolotny [EMAIL PROTECTED] This is exceedingly odd. As a power engineer in training I would say somebody did a really rotten job designing the power supply in one of your machines. Was there any other equipment on either of the machines's outlets? Poor power regulation aside, I don't see how a phase difference affected the serial port. I hope that in general at least this isn't a problem. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
Carey == Carey Evans [EMAIL PROTECTED] writes: Carey It is easy to plug in two mice, dodgy to plug in two monitors, Carey but pretty much impossible to plug in two keyboards at the Carey moment, IMO. Wouldn't it be sort of possible to plug in an ascii terminal to the serial port, hide the screen under the table, move the keyboard over to that second monitor and write some fairly simple program that would read characters of the serial port device and forward them to the Xserver? ---+-- Christian Lynbech | Telebit Communications A/S | Fabrikvej 11, DK-8260 Viby J Phone: +45 8628 8176 | email: [EMAIL PROTECTED] --- URL: http://www.tbit.dk ---+-- Hit the philistines three times over the head with the Elisp reference manual. - [EMAIL PROTECTED] (Michael A. Petonic) -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
This question or ones very like it seem to come up fairly often. Of cource the critical (and hard) part is driving two video cards. It is possible. There was an article in LJ a bit ago describing the Metro-X X server, which can control multiple video cards (though they may have to be a particular type and/or brand. I don't know how interrupts and the like fit in the picture (your average video card uses two of them if I understand correctly). I don't know if XFree has any support for this sort of thing, or exactly how the kernel would be involved (seems it would have to be some way...). If anyone finds anything out, please post it to this list, I am curious also :) On Mon, 23 Feb 1998, Jameson Burt wrote: I seek to use one computer with two full X-windows users. This would be a cheap in time/money approach for my wife and I simultaneously using Linux. I believe I could get a dummy terminal working through the serial port, then display on a second monitor (though I don't know any approach for a second mouse). Is this reasonable, or is there another approach? -- Jim Burt, NJ9L, Fairfax, Virginia, USA [EMAIL PROTECTED] http://www.mnsinc.com/jameson [EMAIL PROTECTED] It is not the shortcomings of others, nor what others have done or not done that one should think about, but what one has done or not done oneself. --Dhammapada [dp command for quotes from the Dhammapada, in Linux] -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] . -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
On 23 Feb 1998, Carey Evans wrote: Jameson Burt [EMAIL PROTECTED] writes: I seek to use one computer with two full X-windows users. This would be a cheap in time/money approach for my wife and I simultaneously using Linux. It might be worthwhile finding a cheap 386 or 486 with a good graphics card. Install a minimum of programs on it, just the X server. If you run xfs on your main computer, you won't even need the fonts. You could do this with even a 200 MB hard disk, I think. You *will* need 2 network cards for this, but setting up two computers on a network under Linux is easier than some single-computer stuff. X is probably too slow over serial. I think most X apps would run tolerably over a null modem cable. If I understand these gadgets right, the can operate at the speed of the serial port, which is about 120 kbps, I think. Even over ppp (33k modem) many apps function reasonably well. (Just another option.) It is easy to plug in two mice, dodgy to plug in two monitors, but pretty much impossible to plug in two keyboards at the moment, IMO. Good point, I hadn't even thought about it. How sad that the part with bandwidth 1/100Mth video is what you can't do. -- Carey Evans http://home.clear.net.nz/pages/c.evans/ GNU GPL: The Source will be with you... always. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] . -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
Britton [EMAIL PROTECTED] writes: On 23 Feb 1998, Carey Evans wrote: [snip] I think most X apps would run tolerably over a null modem cable. If I understand these gadgets right, the can operate at the speed of the serial port, which is about 120 kbps, I think. Even over ppp (33k modem) many apps function reasonably well. OK, you're probably right. I forgot how much faster a null-modem is than a 28.8K modem. It is easy to plug in two mice, dodgy to plug in two monitors, but pretty much impossible to plug in two keyboards at the moment, IMO. Good point, I hadn't even thought about it. How sad that the part with bandwidth 1/100Mth video is what you can't do. Actually, I seem to remember now reading that it could be possible to plug a PS/2 keyboard into a PS/2 mouse port and use it, with a bit of work. This might have been in some GGI documentation. XFree86 is very unlikely to support this usage unless the kernel does first. -- Carey Evans http://home.clear.net.nz/pages/c.evans/ GNU GPL: The Source will be with you... always. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
On 24 Feb 1998, Carey Evans wrote: Britton [EMAIL PROTECTED] writes: On 23 Feb 1998, Carey Evans wrote: [snip] I think most X apps would run tolerably over a null modem cable. If I understand these gadgets right, the can operate at the speed of the serial port, which is about 120 kbps, I think. Even over ppp (33k modem) many apps function reasonably well. OK, you're probably right. I forgot how much faster a null-modem is than a 28.8K modem. However using the null modem cable one must be very carefull about power supply! Sometimes it is possible to destroy serial ports, when two computers are connected to the sockets powered from different phases. I've done it :-(. The safest solution is to power both of them right from the same socket. Wojtek Zabolotny [EMAIL PROTECTED] -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
Wojciech Zabolotny [EMAIL PROTECTED] writes: However using the null modem cable one must be very carefull about power supply! Sometimes it is possible to destroy serial ports, when two computers are connected to the sockets powered from different phases. I've done it :-(. You're probably lucky it was just the serial ports. :-/ One of my company's new shops had trouble with getting the Ethernet going properly and continuously. It was eventually discovered that one PC was on the same circuit as an air conditioner, and switching them to the same socket completely fixed the problem. -- Carey Evans http://home.clear.net.nz/pages/c.evans/ GNU GPL: The Source will be with you... always. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
two keyboards, two monitors, two users, one processor?
I seek to use one computer with two full X-windows users. This would be a cheap in time/money approach for my wife and I simultaneously using Linux. I believe I could get a dummy terminal working through the serial port, then display on a second monitor (though I don't know any approach for a second mouse). Is this reasonable, or is there another approach? -- Jim Burt, NJ9L, Fairfax, Virginia, USA [EMAIL PROTECTED] http://www.mnsinc.com/jameson [EMAIL PROTECTED] It is not the shortcomings of others, nor what others have done or not done that one should think about, but what one has done or not done oneself. --Dhammapada [dp command for quotes from the Dhammapada, in Linux] -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
Jameson Burt [EMAIL PROTECTED] writes: I seek to use one computer with two full X-windows users. This would be a cheap in time/money approach for my wife and I simultaneously using Linux. It might be worthwhile finding a cheap 386 or 486 with a good graphics card. Install a minimum of programs on it, just the X server. If you run xfs on your main computer, you won't even need the fonts. You could do this with even a 200 MB hard disk, I think. You *will* need 2 network cards for this, but setting up two computers on a network under Linux is easier than some single-computer stuff. X is probably too slow over serial. (Just another option.) It is easy to plug in two mice, dodgy to plug in two monitors, but pretty much impossible to plug in two keyboards at the moment, IMO. -- Carey Evans http://home.clear.net.nz/pages/c.evans/ GNU GPL: The Source will be with you... always. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
Re: two keyboards, two monitors, two users, one processor?
Carey Evans wrote: Jameson Burt [EMAIL PROTECTED] writes: I seek to use one computer with two full X-windows users. This would be a cheap in time/money approach for my wife and I simultaneously using Linux. It might be worthwhile finding a cheap 386 or 486 with a good graphics card. Install a minimum of programs on it, just the X server. If you run xfs on your main computer, you won't even need the fonts. You could do this with even a 200 MB hard disk, I think. You *will* need 2 network cards for this, but setting up two computers on a network under Linux is easier than some single-computer stuff. X is probably too slow over serial. (Just another option.) It is easy to plug in two mice, dodgy to plug in two monitors, but pretty much impossible to plug in two keyboards at the moment, IMO. A better option would be to look at the dxt package on sunsite- it is a nfsroot linux boot floppy that you can set up to run an X server on- I've hacked it up a bit, so it will use an X font server such- I may release it at some point in time. It is not the best solution, but it is out there. -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word unsubscribe to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
