Aged Cyber Aunt

How to: LINK TWO PCS using Laplink, XTlink or Interlink

This article was originally written in mid 1990s. Much of this information has been superceded by the advent of CD-R and CD-RW drives and disks. But for older machines and those without re(writeable) CDs this is a good way.

You may have a problem keeping two or more PC's up to date with the same data on each. This can particularly apply with a portable which is less sophisticated than your desktop, and you prefer to use the desktop when possible.

You can backup the data to a floppy disk and restore to the other machine for small amounts of data, or to tape for any amount of data. The latter means that either you need more than one tape backup unit, or if using an external one you have to connect to each machine in turn.

There are many ways to transfer data using a special cable similar to the one used by Laplink. You can use either the serial or parallel ports, different cables of course. Connection via the parallel ports allows faster data transfer. Details of the cables are at the end of this article. I will discuss three ways.

Laplink
XTLink
Interlink
Direct Cable Connect

Laplink

This is a program for transfers between two PCs. First connect the two machines, and start Laplink on each, the program needs to be correctly configured. The same screen is displayed on each machine, and you may work from either keyboard. The disks retain their individual letters on each machine, exactly the same as when they are not connected.

You can transfer either by selecting files, or directories, and include or exclude subdirectories. This is a good way of transferring large amounts of data, but not so good for small as one cannot select by date across directories. There are a number of different versions, for DOS and Windows.

Other Programs

I use two other programs, perhaps less well known, for transferring large or small amounts of data: XTreeLink (XTLINK) which comes with Xtree Gold for Dos, and Interlink, which is supplied with DOS 6.0 onwards.

When using either of these programs you may use a file manager such as Xtree to transfer data between the two machines. This means that, for instance, you may set up Xtree to sort data in date order, descending, (which shows the latest files at the top), across a whole drive, and then transfer in the normal way.

XTLink

This works well with DOS machines, it cannot cope with long file names (those whose names are not in the 8.3 format).

In my opinion this is the simpler method. Install Xtlink on each machine. One will be the master (or local as the program calls it) where you type and the other the remote.

Ensure the Lastdrive statement in the Config.sys on the master allows sufficient letters to include all the drives on both machines.

On the remote machine type: XTLINK S (if you are using a serial cable or 'XTLINK P' if using a parallel cable), a screen will come up saying "Waiting" amongst other things.

On the master / local machine type: XTLINK S L(if you are using a serial cable or 'XTLINK P L' if using a parallel cable). You will see a message: "Host connected via serial (or parallel) port", a list of mapped drives, and the message "Host installed and active". For an explanation of mapped drives see section below.

You may then start Xtree in the usual way, and do your transfers.

Interlink

This works well with DOS machines, it cannot cope with long file names (those whose names are not in the 8.3 format). Interlink is supplied with DOS 5.x and 6.x

Include enough letters in the Lastdrive statement in the config.sys on the master / client to include all the drives on both machines.

To start the master / client include a line in the config.sys such as:

device=c:\dos\interlnk.exe /drives:5

This puts part of the program in memory and indicates how many drives are required in total to be included over the two machines, including floppy drives! (Not only does XtLink not need to be told this but ignores floppy drives on the remote machine). If not using the first parallel port on the master include another parameter such as '/com:1'

There are a number of other parameters that may be set using this method including excluding the remote floppy drives; for more information type DOS HELP at the Dos prompt.

To start the remote / server / slave machine you type 'INTERSVR' at the prompt. If you do this before starting the master / client  machine then connection will be established as soon as the master starts with the appropriate config.sys (see above). If you start the remote after the master, then on the master / client machine type 'INTERLNK' to make the connection.

Both screens will then indicate what the drives on the remote machine are now known as on the master.

Use any program on the master and the remote drives will be included in the list of available drives.

Drive Mapping

Xtlink, if you have the master with C:, D:, & E: and the remote with C:, D:, & E: the system will see the latter as F: G: & H:.

Interlink, if the master has C: D: E: and the remote has the same and a floppy drive, on the master machine the floppy will be F: and the hard drives G: H: I:. It is possible to omit the floppy drive from being included, again see DOS HELP

It is essential to remember which drive is which. You may find it helpful to write them down, though with Interlink the redirected names are left on the remote screen.

Crossover Cables

Parallel cable for Xtlink and Interlink, using 25 pin connectors : 2-15, 3-13, 4-12, 5-10, 6-11, 11-6, 10-5, 12-4, 13-3, 15-2.

Parallel cable for Laplink: the same as above with 14-14, 16-16, 17-17.

Serial cables:


25 pin - 25 pin: 7-7(Ground) 2-3((Transmit-Receive), 4-5((RTS-CTS), 6-20 (DSR-DTR), 3-2(Receive-Transmit), 5-4(CTS-RTS), 20-6(DTR-DSR). In addition my Laplink cable has 8-8 and 1-1.

9 pin - 9 pin: 5-5(Ground), 3-2 (Transmit-Receive), 7-8(RTS-CTS), 6-4(DSR-DTR), 2-3(Receive-Transmit), 8-7(CTS-RTS), 4-6(DTR-DSR)

9 pin - 25 pin: 5-7(Ground), 3-3 (Transmit-Receive), 7-5(RTS-CTS), 6-20(DSR-DTR), 2-2(Receive-Transmit), 8-4(CTS-RTS), 4-6(DTR-DSR)

To cover all combinations you can make or buy a serial crossover cable which has a 25 pin and a 9 pin connector at each end!

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Updated 13 November 2003