HOW TO USE INTERLINK TO CONNECT TWO COMPUTERS Microsoft's DOS 6.0 and later come with a program called INTERLINK, and it is one of the best kept secrets around. INTERLINK provides a fast and efficient way to exchange data between IBM-compatible computers. You do not even use a modem when you use INTERLINK. All you need is an inexpensive cable. This can be a serial null modem cable or a bi-directional parallel cable (a Laplink type of cable). You can find such a cable at your local super computer store. You can also purchase a cable from a mail-order firm like Dalco Electronics: Dalco Electronics 275 Poineer Boulevard Springboro, Ohio 45066 513-743-8042 (phone) 800-445-5342 (toll-free) 513-743-9251 (fax) I have bought several cables from Dalco and have always found the people there very helpful. Ask for a free catalog. A bi-directional parallel cable (Laplink type) will be your best selection because it will transfer data faster. Both computers need to be IBM-compatible. Choose a computer with DOS 6 or later to be the "client" computer. The CLIENT computer is the computer at which you type commands from the keyboard. The other computer is called the "SERVER" computer. So, the server computer is the computer connected to the client computer via the cable, and its purpose is to serve the client. When connected with INTERLINK, you use the client computer to control both the client's disk drives and printers and also the server's disk drives and printers. This is all done from the keyboard of the client computer. It really doesn't matter which computer you designate as client or server as long as you keep a few rules in mind: * You need DOS 6 or later on the client computer. * The server computer must have DOS 3.0 or later. * You will need at least 16K of free memory on the client computer. * You will need 130K of free memory on the server computer. * You will need either a null modem cable or a bi- directional parallel cable (a Laplink type). * The computers need to have a free serial port on each computer or a free parallel port on each computer. You will use the cable to connect the two computers. Check the above list to make sure both computers will meet the requirements. PREPARING THE CLIENT FOR INTERLINK On the client computer, change to the C:\DOS directory by typing at the C prompt: cd \dos Do a directory to make sure that INTERLINK is on the client computer. dir inter*.* In order to use the INTERLINK program, you will need to modify the CONFIG.SYS file on the client computer. To be safe, you should make a backup of your AUTOEXEC.BAT and CONFIG.SYS files on the client computer and have a boot diskette. The boot diskette can provide a way to boot the computer should you find your machine will not start up on the C drive. * Make a boot diskette. Place a blank diskette in drive A and issue: format a:/s This can be used to start the computer in an emergency. To use it, start the computer with this diskette in your A drive. * Use another diskette and copy the AUTOEXEC.BAT and CONFIG.SYS files to it. Here is how: Place a blank formatted diskette in drive A and type: copy c:\autoexec.bat a: copy c:\config.sys a: The INTERLINK program (INTERLINK.EXE) should be located in the C:\DOS directory. Use the DOS EDIT program to change the client computer's CONFIG.SYS file. Before you modify a CONFIG.SYS or AUTOEXEC.BAT file, always have a boot diskette (for safety), and save copies of the CONFIG.SYS and AUTOEXEC.BAT files on a diskette. These can be used in an emergency. Next, you need to add a line to the client computer's CONFIG.SYS file like: device=c:\dos\interlnk.exe /drives:5 To figure out the number for the /drives switch, you need to add up the number of drives on the server computer. The default for the /drives switch is 3. So, if the server does not have over 3 drives, then you do not even have to specify a drive number. Then the device line would look like so: device=c:\dos\interlink.exe The drives on the server will be reassigned new drive letters. Suppose you had two drives on the client computer and six drives on the server computer. Then the /drives switch should be set at 6. In that case you could add a line to the client computer's CONFIG.SYS file like: device=c:\dos\interlnk.exe /drives:6 Let's use an example that calls for 6 drives on the "server." Suppose you issued the command: edit c:\config.sys And you observed that the client computer's CONFIG.SYS file looked like: DEVICE=C:\DOS\HIMEM.SYS DOS=HIGH,UMB DEVICE=C:\DOS\EMM386.EXE NOEMS DEVICEHIGH=C:\MOUSE\MOUSE.SYS FILES=30 BUFFERS=20 STACKS=9,256 NUMLOCK=OFF To add the INTERLINK device line, you may insert it near the other device line. The modified CONFIG.SYS file would look like: DEVICE=C:\DOS\HIMEM.SYS DOS=HIGH,UMB DEVICE=C:\DOS\EMM386.EXE NOEMS DEVICE=C:\DOS\INTERLNK.EXE /DRIVES:6 DEVICEHIGH=C:\MOUSE\MOUSE.SYS FILES=30 BUFFERS=20 STACKS=9,256 NUMLOCK=OFF If you are using EDIT and you have the CONFIG.SYS file the way you want it, you can save the changes like so: f s Then restart the computer so the changes in the CONFIG.SYS file will take effect. TIPS Another option is to use a Query command in the CONFIG.SYS file like: DEVICE?=C:\DOS\INTERLNK.EXE /DRIVES:6 Note the question mark after DEVICE. This results in the computer prompting you each time you re-start the computer, giving you the option to select INTERLINK. The prompt will look like so: DEVICE=C:\DOS\INTERLNK.EXE /DRIVES:6 [Y/N]? Then answer Y to load INTERLINK or N to not load it. If you want to load the DEVICE line into high memory (and the client computer has this capability), you will save about 9K of RAM. To accomplish this, you insert the line using a DEVICEHIGH statement like this: DEVICEHIGH=C:\DOS\INTERLNK.EXE /DRIVES:6 PREPARING THE SERVER COMPUTER If the computer that you plan to use as the server has DOS 6 or later, you will not have to do anything special to prepare it for use with INTERLINK. In such a case all you do is, at the C prompt type: intersvr This assumes that the file INTERSVR.EXE is in the C:\DOS directory of the server computer and that the C:\DOS directory is in the PATH. (With DOS 6.0 and later, this is the way DOS installs itself.) If you are using a computer with an earlier DOS, you can copy the INTERSVR.EXE file to a floppy disk, then copy it to a directory that is in the PATH of the server computer. The C:\DOS directory would be a good choice to copy the file to, as this directory should be in the computer's PATH. To see what directories are in the computer's PATH, at the C prompt type: path You can also copy the INTERSVR files to another computer using the cable: 1. Connect the two computers with the cable you plan to use for INTERLINK. This can be either a null modem cable or a bi-directional parallel cable (Laplink cable). 2. On the computer that does not have INTERSVR, change to the directory where you want to copy the files. A good choice would be the C:\DOS directory. 3. If you are using the serial ports and not COM1, you may have to disable the SHARE command in the AUTOEXEC.BAT or CONFIG.SYS file. You do this with the DOS EDIT program using a REM statement. 4. At the DOS prompt on the computer where you have INTERLINK files, type: intersvr /rcopy 5. Then just follow the prompts to copy the INTERSVR files onto the other computer. They will be copied to the current directory on the other computer. USING INTERLINK Once you have prepared the client and server computers, you are ready to test INTERLINK. With the cable installed and connecting both computers, do the following: 1. On the server computer, at the DOS prompt type: intersvr 2. Restart the client computer. INTERLINK will run on start up as the DEVICE line is executed on startup. 3. On the client computer change to the drive of your choice, making one of the redirected drives the active one. With everything working properly, INTERLINK will detect the cable connection, and you will be presented with a screen of information on the server computer. This screen will show which drives are assigned different drive letters. To get familiar with the different drives, you can change to various drives and issue DIR commands for your confirmation. You can then use standard DOS commands or a "shell" program to copy files from one machine to another. BREAKING THE INTERLINK CONNECTION To break the connection between the two computers, use the server computer and press: INTERLINK is very easy to use once you have it installed. The next time you use it, you can just connect the cable and type the INTERSVR command on the server computer. TIP For more INTERLINK options and information, at the DOS prompt type: help interlnk ========================================================