home *** CD-ROM | disk | FTP | other *** search
- NETWORK TWO PCs WITHOUT LAN ADAPTERS
-
- By John B. Rose
-
- Copyright 1994 by Rose Business Systems Inc. All rights reserved.
-
- This article may be redistributed provided that the article and this
- notice remain intact. This article may not under any circumstances be
- resold or redistributed for compensation of any kind without prior written
- permission from Rose Business Systems Inc.
-
- If you have any questions about these terms, please telephone (516)
- 726-4711, or send e-mail to jrose@bix.com or CompuServe ID 72357,346.
-
- ----
-
- Do you frequently need to transfer large amounts of data from one PC to
- another? If so, you'll want to consider a high-speed connection between
- them so that one computer's disk and diskette drives and printers appear as
- extra resources on the second machine.
-
- This sure beats the tedious method of backing up one machine (on dozens
- of diskettes) and restoring to the other. And it's a lot cheaper than a
- portable tape backup unit.
-
- Unlike a regular local area network (LAN), there's no need to purchase
- expensive Network Interface Cards (NICs) -- just use the parallel or serial
- ports built into both computers.
-
- Likewise, you won't need coaxial cable between the two machines.
- Instead, you can build a null-modem cable (or a special bidirectional
- parallel cable) using standard DB-25 and/or DB-9 connectors available from
- electronics parts retailers.
-
- Typically, you'd use this method when you're upgrading a client to a
- new computer (the "client") and you want to transfer the directories,
- programs, and data files from the old one (the "host").
-
- At least one of the computers has to be running MS-DOS 6.0 or higher.
-
- Here's what you do.
-
- 1. PHYSICALLY CONNECT THE TWO COMPUTERS
-
- Build one of the following cables. If you have INTERSVR.EXE, the
- server program, already on the host machine, or you have a way to get it
- there (such as compatible diskette drives), we recommend the BIDIRECTIONAL
- PARALLEL CABLE; it has a very fast transfer speed, and it doesn't interfere
- with modems and mouse drivers. It's a little harder to build, and it
- occupies the printer port, so choose this one only if you don't want to use
- the host's printer remotely. You can get away with using a THREE WIRE NULL
- MODEM CABLE if both machines have COM ports available.
-
- HOWEVER, if the host is running a version of DOS earlier than 6.0, AND
- the two computers don't have mutually compatible diskette drives, you HAVE
- to build the SEVEN WIRE NULL MODEM CABLE just to transfer the server program
- from the client to the host. Also, the host computer must have an available
- COM1 or COM2 -- higher numbered COM ports won't work.
-
- BIDIRECTIONAL PARALLEL CABLE: Two DB-25 male connectors, and cable
- with at least ELEVEN conductors. If you can't find the multi-conductor
- cable, get thin stranded hookup wire and spiral cable wrap (Radio Shack
- #278-1638). Connect pins as follows:
-
- PC #1 PC #2
- -------------------------------------
- 2 <-----------------------> 15
- 15 <-----------------------> 2
-
- 3 <-----------------------> 13
- 13 <-----------------------> 3
-
- 4 <-----------------------> 12
- 12 <-----------------------> 4
-
- 5 <-----------------------> 10
- 10 <-----------------------> 5
-
- 6 <-----------------------> 11
- 11 <-----------------------> 6
-
- 25 <-----------------------> 25
-
- SEVEN WIRE NULL MODEM CABLE: Two DB-25 or DB-9 female connectors
- (depending on the physical plugs you find connected to working COM ports on
- each computer), and cable with at least SEVEN conductors. Connect pins as
- follows:
-
- PC #1 DB-9 DB-25 DB-25 DB-9 PC #2
- -------------------------------------------------------------------
- TD 3 2 <-----------------------> 3 2 RD
- RD 2 3 <-----------------------> 2 3 TD
-
- RTS 7 4 <-----------------------> 5 8 CTS
- CTS 8 5 <-----------------------> 4 7 RTS
-
- DSR 6 6 <-----------------------> 20 4 DTR
- DTR 4 20 <-----------------------> 6 6 DSR
-
- SG 5 7 <-----------------------> 7 5 SG
-
- THREE WIRE NULL MODEM CABLE: Same as the SEVEN WIRE CABLE above; omit
- the RTS-CTS and DSR-DTR leads.
-
- 2. INSTALL THE SERVER SOFTWARE ON THE HOST.
-
- Typically, you'll want to transfer files from an older, slower PC to a
- newer, faster one that will be replacing it. The older machine, or "host",
- will be running an earlier version of DOS -- say, MS-DOS 3.3. If the two
- computers have compatible diskette drives, just copy INTERSVR.EXE from the
- newer PC's \DOS directory, via diskette, to the older machine.
-
- If you haven't the luxury of compatible diskette drives, INTERSVR can
- install a copy of itself on a remote machine. Connect the two computers via
- the SEVEN WIRE NULL MODEM CABLE. On the client, enter the command:
-
- INTERSVR /RCOPY
-
- The program will prompt you for the COM port number of the OTHER (host)
- machine. Highlight either COM1 or COM2 and press Enter.
-
- On the host machine, enter the commands:
-
- MODE COM1:2400,n,8,1,p
- CTTY COM1
-
- Replace 'COM1' with 'COM2' above as necessary.
-
- The INTERSVR program will copy itself to the host machine.
-
- 3. EXECUTE THE SERVER PROGRAM ON THE HOST.
-
- You can specify options, such as a maximum data transfer rate, which
- disk drives to omit, and which COM or LPT port to use for transfer. Enter
- "INTERSVR /?" for a list of all the options.
-
- On the host machine, enter the command:
-
- INTERSVR
-
- The host is now ready to act as a file server to the client PC.
-
- 4. INSTALL THE INTERLNK PROGRAM ON THE CLIENT COMPUTER.
-
- You can specify which COM or LPT port to use for data transfer, the
- number of host drives to address, and other options. Enter "HELP
- INTERLNK.EXE" for a list of all the options.
-
- On the client machine, enter the command:
-
- EDIT C:\CONFIG.SYS
-
- ... or use your favorite text editor to add a line to the CONFIG.SYS
- file to read as follows:
-
- DEVICE=C:\DOS\INTERLNK.EXE
-
- Also, if a line containing the text "LASTDRIVE" is already in the file,
- raise the drive letter it specifies, if necessary, so that you can add as
- many extra drives as there are drives on the host. Usually, that's three.
- For example, if the client computer already has diskettes A: and B:, a hard
- disk C:, and a RAM disk D:, LASTDRIVE must be at least G: to accommodate the
- new E:, F:, and G: drives, which are known on the host as A:, B:, and C:.
-
- In this example, the line looks like this:
-
- LASTDRIVE=G
-
- If LASTDRIVE is already set high enough, you don't need to change it.
-
- Save the file, exit the editor, and reboot the computer (Ctrl-Alt-Del).
- If the connection is working properly, the server screen will display the
- additional drive letters that now appear as additional drives on the client.
-
- 5. USING THE LINKED COMPUTERS
-
- The host computer's disk and diskette drives and printers are now
- available as additional drives (and, maybe, printers) on the client
- computer. For example, if the host has drives A:, B:, and C:, they may
- become known to the client as E:, F:, and G:. Programs such as the Windows
- File Manager, the DOS Shell, Xtree (tm), and ProFinder (tm) will let you
- copy to and from, move, rename, and delete files, on host drives
- interchangeably with your local drives.
-
- To copy an entire directory, including all subdirectories and files,
- from the host's hard disk to the client's, substitute the correct drive
- letters and directory name in the following commands:
-
- MD C:\WP51
- XCOPY G:\WP51\*.* C:\WP51 /S
-
- 6. CLEANING UP AFTERWARD
-
- When you're finished using the host's disks, you can stop the server
- program by pressing Alt-F4 on the host keyboard.
-
- On the client computer, edit CONFIG.SYS and delete the INTERLNK command
- line. It's generally OK to leave LASTDRIVE set to a high value. Save the
- file, exit the editor, and reboot.
-
- 7. READY-MADE CABLES
-
- You can save the time and uncertainty of building your own cables by
- purchasing factory-made ones. If your retail store is out of them, we'll
- cheerfully ship the following on receipt of your check or money order.
-
- #219: 4-head 7-wire null modem cable (female DB-9 & DB-25 each end) US$19.95
- #310: Bidirectional parallel cable (male DB-25 each end) $19.95
- #248: 6-head cable, use for parallel or serial $29.95
-
- Cables are guaranteed to work, or return them for a refund. Priority
- Mail postage to U.S. locations is included; NY AND NJ ADDRESSEES ADD YOUR
- LOCAL SALES TAX. Add US$5.00 to Canada or Mexico; $10.00 for other
- international destinations. Prices are valid through December 31, 1994.
-
- ROSE BUSINESS SYSTEMS INC.
- Since 1976
- 511 Head-of-Pond Road
- P.O. Box 630
- Water Mill, NY 11976-0630 USA
-
- Phone: (1) (516) 726-4711
- E-mail: jrose@bix.com
- Compuserve: 72357,346
-