Posted in Computers & Tech / Networking
Author: snutz411 Total-Replies: 9

Make sure you have file and print sharing enabled on both printers. You do not need to install the drivers first on the second computer because once it finds it over the network, then it will install the drivers for you.

Of course you have to make sure your printer is set to be shared over the network. On the second computer you might to want physically add the printer by doing \\master computer name\printer name.

If you did it all right, then you'll only have to do \\master computer name, and the rest should pop up

Posted in Computers & Tech / Networking
Author: nightfox Total-Replies: 21

Make sure you actually use the assigned shared name of the printer. I always use windows to do that and then it usually says that the host doesn't have the correct print driver installed and then I just browse to the .ini file on my server. If something doesn't work, just go back to the begining. On the remote computer (the one the printer ISN'T connected to), delete the printer. Start using the add printer wizard and then choose network printer and then browse to the location of it. That always works for me.

[N]F

Posted in Computers & Tech / Networking
Author: mastercomputers Total-Replies: 11



Are the computers networked correctly? Can you ping both computers and get a response, allow both computers through your firewall for this to work.

The type of network you may want is a P2P network.

Basically what you do is right click on the drive/folder to share, go to sharing and then allow share, you can make it read only (can't delete or write files on whatever you share)/full control etc, you can add a password to. If this isn't there, go into your network properties and there should be a checkbox to allow file and print sharing, make sure it's checked then attempt this step again.

There should be already a shared folder which is enabled by default in which you should be able to access going through network neighbourhood, if not, you may need to configure your firewall correctly to allow file sharing.

You can then map shared drives/folders as network drives on the other computer for easier access.

If you need more help, just ask, I would have given you a better step by step but I currently ain't in Windows so I'm going by memory.

Cheers,


MC

Posted in Computers & Tech / Networking
Author: vujsa Total-Replies: 25

Kind of small list here:

1. P4 Desktop (yeah like it would fit on a desk)
   
2. Compaq P4 Laptop
   
3. Cable Modem
   
4. TiVo DVR / DVD-R/RW
   
5. Linksys WAP/ Router / Switch
   
6. Cannon Printer via Desktop
   

Soon to add:

1. PS2 (old one just needs an adapter)
   
2. Second Desktop
   
3. Second Printer
   
4. Out of ports, a second switch it looks like.
   

vujsa

Posted in Computers & Tech / How-To's and Tutorials / Programming / C and C++
Author: Aditya Total-Replies: 6

Writing Interrupt Service Routines(ISR s)


It is assumed in this tutorial that you have knowledge of the C language. Although something about pointers is mentioned but this is NOT a C language tutorial. So here we go.

The Basics

Many functions of the computer are performed by use of interrupts. These include the typing, printer, task switching etc to name some of them. Now how does these things happen? We are here to answer some of these questions.

Pointers in C language:

Pointers in C language are an amazing thing to work with and very dangerous also if you don’t know what you are doing with them. Now since you know C I assume that you must also have the basic knowledge of pointers. So we move on to the better stuff.

As you know pointers can be made to point to just about anything but we are interested here in pointers to functions, why is that you will know shortly.

Pointer to a function can be declared as shown below

<return_type_of_function> (*ptr)(<arguments_of _function>)

PS: The parenthesis around the ptr are necessary. Why this is necessary you will know when we describe the rule of reading what pointer declarations mean.

Let’s see an example of this. Consider that we have a function named myfunc with prototype as ( void myfunc() ), now to declare a pointer to this function from the above rule will be like this
void (*ptr)().

This declares ptr to be a type of pointer which points to a function that takes no arguments and doesn’t return anything. Note that the function this pointer points to hasn’t been told yet so this pointer is dangerous to use.

Initializing the pointer is very easy just do ptr=myfunc; and we have the pointer ptr pointing to the function myfunc since the name of the function appears to give the address of the function where it is stored just like arrays where name gives the address of the array from where it starts.

Similarly if we had a function with prototype as (int myfunc2(int,int)) the pointer to this function will be declared as int (*ptr)(int,int). Actually this pointer can point to any function with a prototype as that of myfunc2. I think you got the idea.

Rule to read pointers declarations

Well this rule is not some kind of a standard but it almost never fails however you are very smart people I think you will find something where this rule doesn’t apply.

THE RULE:

For any type of pointer declaration start from the name of the pointer variable then go to right and add up to the declaration meaning after that go to the left and add to whatever you just found about the declaration of pointer. You will be stopped whenever you find parenthesis or some terminate symbol like ‘=’. Let’s take a few examples to make this more clear

1.) int *ptr; The meaning of this declaration according to above rule. We start from name ptr then we go to right we find a ‘=’ so we move on to left and find a ‘*’ so the declaration upto this point is “ptr is a pointer…….” now since we didn’t find any terminators we continue moving left and find an ‘int’ so the declaration means “ptr is a pointer to an integer”.
2.) int (*ptr)(); Applying the above said rule we start from ptr then go to right and find a parenthesis. So we move to left and find a ‘*’ therefore till now “ptr is a pointer”. Now since we find a “(“ we stop moving left and move right and find “()”. Therefore the declaration till now becomes “ptr is a pointer to a function which has no arguments” we are stopped by ; so we move left again there we find an int so the declaration is “ptr is a pointer to a function that takes no arguments and return an integer value”.
3.) int *ptr[5]: starting at ptr move right we find “[5]” this means till now “ptr is an array of 5” we are stopped by “;” so we move left and find a “*” therefore decleration till now means “ptr is an array of 5 pointers” we continue moving left since there’s nothing to stop we find “int” so the full declaration becomes “ptr as an array of 5 pointers to integers”.I think you got what I’m saying. So how about you trying some examples …

Back to writing ISR s

With the pointer terminology clear now take a look what these pointers mean in the code. Well there are 2 kind of pointers

a ) which we know
b ) which our teachers never taught us.

Actually there are 3 types.

1) near
2) far
3) huge

Near Pointers: we all know these so there’s nothing to talk about them really. These are the ones that our teachers dared to tell us (thanks 4 that). These pointers are 2 bytes long always i.e. any pointer that you declared normally they are 2 bytes long. This permits only 2^16 values which implies that you can access only the code which is in your data segment (since 1 segment is 64KB = 2^16). Any attempt to access data will result in segment protection error from the OS.

Far and Huge Pointers: We take both these two since they are common and differ only when some arithmetic is performed using these pointers. Yes I think you have guessed these type of pointers our teachers never dared to tell us so something must be special about them!

Far and Huge pointers are both 4 bytes long. This means they can they can handle about 2^32= 2GBof memory locations!! Now since we don’t have that much amount of memory when we are real mode (when computer starts up) we are safe since only 1MB is available (only 20 address lines available instead of 32 present address lines). We can access the whole of memory when we are in protected mode. This mode gives the whole 2GB memory as a flat i.e. no segments are available when in protected mode. But since we are in real mode our max memory limit is 1MB and our memory is fragmented into different segments of 64Kb each in size.

Ok. So now you will ask we have 20 address lines and since each segment is 64KB= 2^16 how do we put the correct address. Well this is already done for you in the processor. To access any memory location in the 1MB limit we first find the starting address of the segment then to this address (base address of segment) an offset of 16 bits is added. The way these addresses are added is a bit tricky. First the segment’s address is left shifted by 4 bits (padded with 4 zeros in the end) and then the offset is added to it. Now this is a full 20 bit address and processor use this address to locate a memory location in the 1MB limit. The shifting need not be done by us since processor does that for us we just need to supply the segment’s base address and an offset within that segment.

All segments starts at some multiple of 16 also called a paragraph boundary. This is because for each 16 bit segment address it is first left shifted by 4 bits ( 2^4=16 bytes).

One more thing where these pointers differ from each other is in the way they are stored. Far pointers are not normalized while huge pointers are normalized. Normalization means that they have most part of the address in the segment. This is not a problem if you will perform logical / arithmetic operations on such pointers but if you do then using huge will benefit you since the results will be same as expected while with far pointers you may get strange results. Huge pointer arithmetic is therefore more complex which requires macros and thus slows down the performance.
Declaring far /huge pointers

The Turbo C provides us the keywords far and huge to declare such pointers. Just add these keywords and declare these pointers like you normally do.

Example int far *ptr; (this ptr is a far pointer to an int)
int huge *ptr(this ptr is huge pointer to an int)

Why do we need these pointers while writing ISR s?

Well as I said before with normal / near pointer declaration we can’t access the code outside of our data segment. Since ISR s require us to go beyond our data segment we must use these pointers. Only far can be used huge may not be required since there’s not much in the data segment which we need to access. Using huge pointers we can access more than 1MBs of data in the data segment while 1MB when we use far.


The Booting process of PC

When we push the start button of the PC many things are done. First a POST is done which checks the computer for its resources after the check is performed the BIOS (Basic Input Output System) is given the control. The earlier versions of BIOS used to come with BASIC loaded on them so in case an OS is not found the BASIC used to run on the computer now this doesn’t happen and that’s why we see Disk Error message when no OS is found.
The purpose of the BIOS is to make computer ready to support the OS so that is can start up. Its purpose is to load the interrupt routines and start video output in text mode. The interrupt routines used by BIOS are very basic and they don’t interpret the data its up to the OS getting loading to make use of that data.

The interrupt service is loaded through an IVT (Interrupt Vector Table) this is done so that if any other routine is required for some interrupt instead of the one provided by BIOS we just need to change the values present in the vector table. This makes interrupt handling robust.

Interrupt Handling Process

Whenever an interrupt occurs the processor stops whatever it was doing and handles the interrupt. Each interrupt (256 in total supported by Intel’s processors) has an entry in the IVT which is made by BIOS. Each entry is 4 bytes long. Therefore whenever an interrupt occurs its number is multiplied by 4 to access the ISR location. These locations are located in the low memory area of the memory, thus to have access to code outside of our segment we need to use far /huge pointers.

An ISR is just a module which replaces the entry currently in the IVT to itself. Since these modules already present in the memory don’t have any names therefore the only way to access them is by use of pointers to functions.
TC provides the keyword interrupt for writing ISR s. This keyword may be different on different compilers and the code that we will compile is for REAL MODE only (16 bit code). For 32 bit code we have to switch into protected mode which I don’t know myself yet. Also the IVT thing works only in REAL MODE in protected mode this changes to IDT (Interrupt Descriptor Table) this is way 2 advanced to handle here.

Things that we need

TC 16 bit compiler (that IDE one)
Functions setvect() and getvect()
A big heart to handle the errors that XP will show you when you run these programs!


The functions setvect() and getvect() are both defined in dos.h. They provide a neat way to set the IVT for an interrupt to our ISR. A small program will demonstrate this.


The above program creates an ISR for the keyboard interrupt( number 9). When we are inside an ISR we can’t generate another interrupt since we can handle only 1 interrupt at 1 time. Therefore we have written directly to the VDU in the our ISR. Since there are 80 cols and 25 rows => (80 X 25 =2000) memory locations. Each row/col entry comprises of a 2 byte value( that's why looping 4000 times). The even byte (1st byte) gives the value present at that location while the odd byte (2nd byte) gives its color and other attributes such as blinking, intensity etc.

For using the internal clock use interrupt number 8. Watch what happens then!

We have called (*prev)() from inside the our ISR this is necessary since at this point if time we don’t know what actually takes place on pressing the key. Therefore its best to call the previously stored ISR after we are done for smooth operation.

To compile as a CPP file use 3 periods(...) in the argument section of the functions declarations. However this is only useful when we are not interested in the values present on the stack.

When an interrupt occurs the processor responsibility is to save its state so that it can resume from that point when handling of interrupt is over. By default the processor just pushes 3 values on the current stack. These are the flags, IP(Instruction Pointer) and the CS(Code Segment) register. However to successfully execute the program we need that all registers state be saved. This is done by the compiler for us.

Use this command tcc –s <filename>. This will generate an ASM file with the same name as that of the filename given. Now if you take a look at the statement proc our far in this asm code you will see that all general purpose registers are pushed before any instruction in the ISR is executed. However there’s no mention of the CS,IP and flags but they are present on stack and their values can be changed. These changed values if any will be popped back into the registers when the ISR is over.

PS: Intel specifies that you can’t change the value in the IP register directly however through stack this can be done easily. If this gives you some bright ideas please meet me to discuss that I have thought on it but some problems are there!


Using Stack inside of ISR.

To use stack we need to pass some argument in the ISR so that these values are available in that argument and we can use them. The best way to do that is to declare a structure in the order in which the values appear in the ASM code while pushing. Also remember that to use completely Stack values the IP,CS and flag registers have also to be present in the structure. The structure is shown below

struct INTERRUPT
{
unsigned bp,di,si,ds,es,dx,cx,bx,ax,ip,cs,fl;
};
Now using this structure we can get values present in all the registers . I have developed a program to just that when the user presses the keyboard (i.e. we use interrupt number 9) to display the values.


Another Program but it doesn’t work that well but shows the values of all register is shown below. Just press a key to get out of it If you can pls correct the malfunction that arises while printing values. Also if you see any negative values in the registers its just that the address is being interpreted or it has exceeded the maximum limit of the data type. No NEGATIVE addresses are there!!!


That’s all for now try some programs by getting info on various interrupts. Note that all are not defined by the BIOS and are user defined interrupts like interrupt 0x21 this is defined by DOS not the bios. However you can use it and any other up until 255 (0-255 total interrupts).
Please give some remarks for this tutorial. So that I know people are reading the stuff I write.

Happy Coding.

Posted in Computers & Tech / Software / Freeware
Author: starscream Total-Replies: 1

Remember those flipbooks in 90's ? or earlier than that ? I remember playing with them for some of the sport related action flips. Some cricketer playing square drive or bowler hitting the wickets. I once thought if it was possible to have similar flipbooks these days. Randomly came across one site where such software was featured. I gave it a try and found that this software can be a good option for those who wants to print flipbooks at home. Though the current version seems to be only for personal use and it flashes this message for those who wish to use it for commercial purpose. That aside you can use it for your simple flipbooks, like cartoons or some webcam funny activity. There are plenty of uses of this flipbook if you have enough idea. I am thinking of making it as Christmas present.

You can download the flipbook from official flipbook printer suite site.

So far from what i have managed to play with this software, you can use the jpg images, video files and the other formats from which you can create small still that are going to be printed in flipbook. You can delete or add custom message into the pages aswell. Also you can use the software for the removal of excessive un-necessary frames. It'll let you test the flipbook virtually on your computer before you print it out on paper. You can change and make your own flipbooks of size of your choice.

Result of the software is something like this :



Perfect for those who want to use it as gift this thanksgiving or christmas holidays. You can however use it on any other occasions as well. But it is free for personal use. You can use it with some restrictions, which i have not understood so far. Have to check for more restrictions and the possibilities.

Hope someone else find it useful.

Posted in Computers & Tech / Software / Business & Productivity
Author: BlueMountain Total-Replies: 9

well you can install a acrobat pro 6 or 7 (not acrobat reader), so the software will add a virtual pdf printer to your computer, and you can just use print from your excel and select the PDF printer then it will ask you where to save the PDF file, and just click OK to generate the PDF file.

also there is a software called PDF factory, it works in the similar way as the acrobat pro.

Posted in Computers & Tech / Networking
Author: snutz411 Total-Replies: 13

Well in about 3 months, I'll be moving back into a house with my college friends.

The house is full of computer science majors (including me) with a bunch of gaming computers (not me).

We already have a network setup throughout the house, but it is my task to upgrade the whole thing.

The first piece of equipment to be replaced is the current Wireless Router which will be upgraded so a Linksys Gigabit Switch (10/100/1000) with 5 ports. 4 of the 5 ports are gigabit, while the last one is 100mb. The four computers in the house that game the most will be using the gigabit ports for obvious reasons. The fifth port will be connected to a DLink wireless router through the uplink port which will just extend our nettwork for the wireless users in the house (me). Now from the Dlink wireless router we will connect a 5 port switch (basic 10/100) for random devices that need connection to the LAN like our XBOXes or PS2s.

Fun stuff but the gigabit router alone will run about $340. The other equipment is already in the house and CAT5 is plentiful. We might even add a printer server during this process, but that's what the second switch is for.

Posted in Computers & Tech / How-To's and Tutorials / Networking
Author: SilverFox Total-Replies: 0



This tutorial is to help you set up a wired Ethernet based peer to peer network, which is a type of Local Area Network (LAN for short). Here I will guide you through the steps from laying the wire to the very last thing (which for me is setting up print sharing). If you have any questions please PM me or post here.



There are many types of networks in the world of computers, the internet itself is nothing but the linking of thousands...or maybe millions of LANs, Wide Area Networks (WANs); linked together via Internet Service Providers (ISPs). Within this collection of networks are many virtual networks, they all come together to be what we tend to think of as the "Internet", "Net", "Web" or a host of other names. The Internet is governed by Protocols, today we are going to use the most common protocol, Transmission Control Protocol/Internet Protocol (TCP/IP for short). TCP/IP has served as the main protocol for well over decade now, and that is what we will use to set up your network. I won't go on as I'm getting off topic.



Since a LAN is a physical network you need some things to link the different PCs.

You will need (in addition to what is needed to set up your basic internet from your ISP):

1. 1 Router or Hub (Router is better and is used in this example)
   
2. 1 Ethernet Cat 5 Cable and one more for each PC
   
3. An AC Adapter for the Router
   

Routers range from $30 to $60 and are available at most retailers. You might also need clips to run it along the wall, these are available at most major retailers in different sizes with nails already.

For starters run an Ethernet cable from your Cable/DSL Modem to your Router, plug it into the appropriate slot. Then run Ethernet wire from the Router to the Ethernet jack in the back of the PCs. If you need to run a cable along the wall and/or ceiling place the clips to hold the cable in every 3-5 feet, preferably with the nail on the bottom. Once all Ethernet cables are run then plug the AC Adapter into a 110 V (in US) AC Outlet and then into your router. If your router has client software please run it.



Then go to My Computer and then "My Network Places". Click "Set up a home or small office network".
[img]http://www.imagefilez.com/out.php/t77290_howtoaccess1.GIF[/img]

How to access My Network Places

The wizard will run. Then go to the other PCs and repeat the wizard adding them to the appropriate work group. The wizard be default chooses the generally correct choices, however in the following pictures I highlight the options which you should chose.

[img]http://www.imagefilez.com/out.php/t77291_howto2.GIF[/img]
[img]http://www.imagefilez.com/out.php/t77292_howto3.GIF[/img]
[img]http://www.imagefilez.com/out.php/t77293_howto4.GIF[/img]
After that step install the printer drivers on the other PCs. You are then setup with your own Peer to Peer LAN.



I plan to add upon this tutorial, I wanted to take pictures of the hardware mentioned but my camera wasn't working.

Posted in Computers & Tech / Networking
Author: bluefish Total-Replies: 11

I had a similar problem. This might not be the same as yours, but for whatever reason one computer on the network would not appear as part of the workgroup even though it was. To resolve it, I just typed "\\computer_name" in the address bar (windows explorer/internet explorer). That got me to the normal screen with files, printers, etc.

If you want to set it up so you can access it more easily, go to My Network Places, and click Add a Network Place under Network Tasks (on the left). Follow the directions, select "Choose another network location", and for the network address type "\\computer_name\folder". The annoying thing is you can't link to "\\name", but you can just press Up in whatever folder you choose to access that page.

Posted in Computers & Tech / What's New...?
Author: cyborgxxi Total-Replies: 6

I wouldn't mind one of those. It would add a little light to my boring existence on earth. lol. But I would actually like one in my room. Then I wouldn't want to break it so much when the alarm goes off. It would definitely be a change of pace.

Posted in Computers & Tech / Networking
Author: WeaponX Total-Replies: 15

Today I was trying to setup shared internet for someone and was having lots of problems with it. They are using AOL DSL and had their ISP's modem. They have a Linksys router (forgot what model...WRT something) and I tried almost everything I can think of to no avail.

Here is the problem. The modem connects to the computer using USB ONLY. It has an ethernet adapter in the back of the modem but it will not work (needs the USB either way). After playing around more for over an hour, I came to some "conclusion" that the other machines need the modem to be connected via ethernet and not USB.

Does anyone know how to make this setup work? The current computer is connected to the modem directly using USB. This computer will not be wireless. But they have a desktop and laptop that they do want to be wireless. Both computer wireless cards work since I had another setup upstairs and they can go online without a hitch there. Upstairs is using cable modem (ethernet) connected to another Linksys. No problem there.

I want to add that I tried to make the locally connected computer to some kind of "gateway" and see if it will connect that way. But couldn't even get the other computers to ping its IP address. This computer also requires signing on AOL to access the internet. I have never seen DSL requiring this before, but that's how it was setup here. Not sure if they may play a part in this big mess.

I just want to know if this USB connection can be causing the problem in case I meet another similar situation next time.

Thanks.

Posted in Computers & Tech / Networking
Author: yordan Total-Replies: 11

I have this problem with one of my computers.
I found a way of overriding it, just try it.
On computer 2, open a DOS prompt window, and type "route add computer_1 the-router" (replace the_router with the IP of the router, something like 192.168.1.1 probably).
If not successful, go on computer 1 and "route ad computer_2 the_router".
Tell us if this works or if your problem is differerent form mine.

Posted in Computers & Tech / Software / Graphics & Web Design
Author: bhupinder Total-Replies: 6

Well i have been looking around for a lot of photo editors....Photo Shop is very good but cost a lot of money.So i found GIMP which is very good but i found a one thing in it that i didn't like, but i don't know if it is fix able.Well when every you start from scratch on a for a picture..You have to add text or pictures, and the box around it doesn't cover the whole size of the picture. You can only edit in side that box.So when every i go to do a bucket fill only the box gets filled the rest is white. Does someone know how to fix that? Other then that i find a Gimp fantastic photo editor. So if some one knows how to do bucket fills out side the box please tell me how. thanks

Gimp shop isn't what i would use on my computer it has way to many shut downs i don't know if its just my computer or not, but Gimp shop is a copy of GIMP. GIMP is a newer version. but GIMP Shop they say is a copy of Photo Shop which i say 'NO' to. It is no were close to Photo Shop, and half way threw your photo editing it shuts down. So i just got rid of it.

VCW VicMan's Photo Editor is a pretty good photo editor. Just doesn't have some things to edit photos
unlike GIMP. You can edit photo any were in this but you cant do smudges, paint brush, and ext. but i still use it because GIMP doesn't provide some of the stuff this does.

Now thats what i think of these photo editors but you might have or thoughts about them so please post them here. I would certainly like to hear more about photo editors.

Posted in Computers & Tech / Software / Freeware
Author: doudou Total-Replies: 14

Does PrimoPDF allow you to add link or bookmarks to the PDF file? What about graphics? I assume you can probably add graphics to the PDF file.

Thanks