Tuesday, January 27, 2009

Turn One PC to Many - MultiPC, Thin Client

One CPU connected with many keyboards, mouse, monitors, web cams,speakers and microphones so that more than one user can operate a computer simultaneously is the concept of MultiPC or Thin Client as I am going to discuss here.

Here in Kathmandu, I saw this system for the first time when I was setting up a cyber cafe. Very limited budget and heavy cost of hardware along with the expectation of small return everyday of a cyber cafe made me think about the alternet way to reduce the installation cost. When I started my cyber cafe, the cost of a computer set (some how working medium quality) was around 30 thousand rupees. That way purchasing fifteen computer sets would directly cost 4,50,000 Rs set aside the cost of furnitures and decoration. When I calculated the expected income that a cyber may earn everyday was quite disappointing with respect to this investment. The cyber rate at that time was Rs. 20 per hour and we had to manage it to Rs. 15 for us to sustain and attract customer. That way, the daily income from the cyber would be Rs. 1,125 if all the computers were occupied all five hours a day. So investing much amount on cyber was useless.

I started to search on internet if any alternative is found to reduce the system cost in considerable amount so that a cyber could be run with a safe invest. The first thing I found was Applica, a system that claimed as I expected, but the problem here was I need to import all the hardware, wires, switch/router like devices, Software everything and the whole system was rather different made me doubt if it could be applied to a Cyber Cafe. Next thing I found was Userful a multiuser software based solution that could connect upto 10 user stations with a CPU. This was quite OK as I could purchase the required devices from my local market. But this was with a Linux Operating System and I was sure that my customer here are not familiar with Linux and would feel uncomfortable. This solution too became useless. I found a free download of Userful too. I downloaded but never tested, thinking that here in Kathmandu the general users of Cyber Cafe won't appreciate it much.

In the course of my quest for the multiuser system, one day, I landed on thinsoft site. There I found beTwin. This was the solution. It run on Windows. Upto 5 stations could connect to a CPU. Did not require heavy processing neither lot of RAM. It supported Networking and Installation was quite simple. My intuition told me that this is the right choice.

I bought 5 CPUs, one for the server and four for the client stations. I did not like to share the server CPU as it had to work for scanning, printing, operating cyber timer software and store a lot of backups. One CPU will be connected with four stations including the host staion.

List of Devices, as I remember, I purchased
Monitors: 17 pcs
Keyboards/mices: 17 pcs
Headsets: 4 pcs
Printer: 1 pcs
Scanner: 1 pcs
Webcam : 4 pcs
Monitor Extension Data Cable: 12 pcs
USB extension Cable : 12 pcs
PS to USB converter (Y-Cable) : 12 pcs
USB splitter : 4 pcs
I decided to use the voice chat and video chat on only four of the stations considering the internet bandwidth requirement and extra harware. One switch connected those five CPUs through CAT5 cables to form LAN.

CPU configuration I purchased
Intel 845 GVFN motherboard (this was the latest then)
Hynix 512 MB RAM 2 pcs
VGA/Sound Card/NIC Card inbuilt in motherboard
80 GB PATA hard disk
ATI 8MB VGA Card 3 pieces (to connect with added monitors; one VGA was inbuilt)
How I Installed MultiPC
Positioned all the CPUs and Monitors, Keyboard/Mouse on their designed places.
Connected one monitor, keboard and mouse with a CPU on the board's built in port. So a single set of computer was prepared.
Installed Windows XP on that CPU.
Installed all device drivers. Device Drivers of ATI VGA Cards displayed conflict. I removed the windows installed drivers for ATI VGA Cards and reinstalled the drivers from the CDs that came with the VGA cards. The conflict was resolved.
Then I inserted the Y-Cable one by one.
Checked on Device Manager to see if any conflict exists. Everything was fine. Y-cables had installed the Human interface device and Device Manager listed four monitors, four keyboards, four mice.
Connected the three keyboard and mice on those Y-Cables (Ps2 to USB converter).
I checked if all mouse made the mouse pointer move or not, similarly, all keyboards typed or not. All those mice and keyboard works on the same monitor. OK perfect.
Then I connected the three monitors on that CPU on the ATI VGA Card's Port.
Then the 'Enable Extended Desktop Support' was turned on from the system properties (Right click on the desktop and chose properties, and go to the settings tab)
When I clicked Apply button on Settings tab of System Properties dialog box all the connected monitors turned on displaying the desktop. Only the host monitor contained the taskbar and Start button all others were displaying only the desktop.
Then I installed the beTwin - MultiPC software. After it finished installation, the computer restarted. It displayed prompt on each of the monitor one by one to press OK from keyboard and click with mouse. This step was to identify which keyboard and mouse works with which monitor.
Then again the computer restarted.
On this restart, all the four monitors were running perfectly independent and the keyboard and mouse worked only with that particular monitor. So the stations were formed.
On the host computer, it was asking for the license. When I provided the license and restarted, the system was ready to operate
I took the backup of the whole system. The hardware cloning was done with a small tool called Snapshot. And this image was burnt on other three hard disks to prepare other three sets of 4 stations.
When other computers were ready, beTwin asked for the license for each of them.
When everything was ready I locked the system drive with DeepFreeze to protect the system configuration and ensure proper running.
Was beTwin MultiPC Successful or Gave Problems
I should say to the largest scale that the beTwin MultiPC was successful. This does not mean that there were no problems. But the heavy saving on investment and excellant performance of MultiPC made those problems negligible.

System Hang Made all Stations Hang

This is true. This happened many times. Cyber users accessed any sort of sites and the viruses or spyware when infected one user started disturbing all other station connected with that CPU. Later on I learnt that this happens when any user logs off the station. So the problem was resolved after I installed the virus and spyware dectection system on LAN Server and removed the logoff facility (from windows group policy editor) from user stations.

Could not Use for Computer Games

This is partially true. Flash games and other online games run without any problem. But those games that require heavy processing or too much RAM were impared in this system. If one station played the game other stations happened very slow. I could not find any solution to this proble.

Single IP Address for All Stations

Though there are four or five stations on a system all of them share the same IP address of the host station. There might be solution to provide different IP addresses to each station (though virtual IPs) but I did not find any or I did not bother for that since it never disturbed on any functionality.

Is It Good to Apply in Schools?

I refered to some schools here in Kathmandu. They worked well and they are still using this system. But there is a problem for them in schools. Still our secondary level school curriculum contain the Qbasic programming language and if you run Qbasic in one station all other became sluggish. And I did not find any solution yet. I don't know how it happen for C or C++ interfaces. If you can compromise with Qbasic problem then its OK for schools as well.

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