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- I thought this excellent guide to PC Cables needed a slight update.
-
- The original work is contained in the CABLES1.TXT file by Bill
- Becwar and is included in this ZIP file in its entire, unaltered
- state.
-
- Below I have included the layouts to the cables I have worked with
- recently that might be of help to others.
-
- Taking the disclamer from Bill Becwar, I repeat it below to prevent
- any thought that I may be held liable for any problems this guide
- may or may not cause you or anyone else.
-
- -----
- LEGAL STUFF - This guide is as complete and accurate as I can make
- it, however, I can't be responsible for errors, omissions, typing
- mistakes, bad downloads, or your dog biting you. I know that
- somebody, somewhere is going to cross a wire. Best advice if you
- want to build one of these cables: Complete the wiring all in one
- work session. Then check the connections, preferably with an
- ohmmeter. Go away for a while and do something else, then return
- and CHECK the connections again. If you have any comments or find
- any errors, leave E-Mail to Darrell Bivens on Silver Bullet BBS,
- (615) 337-9683 Sweetwater, East Tennessee. Good Luck!
- -----
-
-
- Null modem cables (Several variations)
-
- The first variation is explained in an excert from the ZIP162 DOC
- file. The ZIP program will allow computer <> computer file
- transfers through a null modem cable. It can even clone itself over
- the cable (in case the disk drives are not compatible/working).
-
- I have tried this cable with Central Point Software's DriveMap 1.0
- program and Lap Link V 5.0. It works perfectly. Also note if you
- build a 25 <> 25 pin cable and you need to connect to a 9 pin COM
- port that a STANDARD 9F > 25M adapter and/or adapter cable will
- connect the correct pins.
-
- I have not tried a 9 <> 9 pin cable using a 25F > 9M adapter. It
- may or may not work. I don't have an cable of this type to check.
-
-
- Excert from ZIP162.DOC file:
-
- "----------------------- C. APPROPRIATE SERIAL CABLES ------------------------
-
- SERIAL NULL MODEM CABLES, in various combinations of 9- and 25-pin
- connectors, are available from a wide variety of sources, and a simple cable
- in the configuration you need (for example, DB9 to DB25 female) should cost
- less than $10 at Radio Shack or many computer stores. Double-headed null
- modem cables (both 9 and 25 pin on each end) are also made, and would be ideal
- for use with ZIP; I am told that a good source for these is:
- DALCO, 233 Pioneer Blvd, Springboro OH 45066; (800)445-5342
-
- If you're building or shopping for a cable, you need a "null modem"
- cable, meaning the transmit and receive data lines should be crossed, and the
- signal ground connected straight through. (The pin numbers depend on whether
- you have a small DB9 or large DB25 connector, see figure.) No other
- connections should be needed; ZIP uses no hardware handshaking lines. (NOTE:
- ZIPDUP does require the DTR connections between pins 20/4 and 6.)
-
- |--COMPUTER 1--| |--COMPUTER 2--|
- DB9F or DB25F DB25F or DB9F
- pin 2 - - - - 3 - - - - - - - 2 - - - - 3 \ transmit &
- 3 - - - - 2 - - - - - - - 3 - - - - 2 / receive data
- 5 - - - - 7 - - - - - - - 7 - - - - 5 - signal ground
-
- pin 4 - - - - 20 - - - - - - 6 - - - - 6 * \
- 6 - - - - 6 - - - - - - - 20 - - - 4 * \handshaking (optional)
- 7 - - - - 4 - - - - - - - 5 - - - - 8 /(* required for ZIPDUP)
- 8 - - - - 5 - - - - - - - 4 - - - - 7 /
-
- Actually, any serial cable that doesn't work by itself, should work with a
- "null modem adapter" attached. If available, use a well shielded cable; high
- speed transmissions can be especially susceptible to RF interference."
-
- ----------------------------------------------------------------------------
-
-
- In talking around and asking several Tech. support persons I received
- some variations on the null modem cable. Below are the most to least
- common types 'believed' to work. (Using the chart layout from above)
-
- |--COMPUTER 1--| |--COMPUTER 2--|
- DB9F or DB25F DB25F or DB9F
- pin - - - - 1 - - - - - - - 1 - - - -
- 3 - - - - 2 - - - - - - - 3 - - - - 2
- 2 - - - - 3 - - - - - - - 2 - - - - 3
- 7 - - - - 4 - - - - - - - 5 - - - - 8
- 8 - - - - 5 - - - - - - - 4 - - - - 7
- 6 - - - - 6 - - - - - - - 20- - - - 4 (As you can see here, pins
- 1 - - - - 8 - - - - - - - 20- - - - 4 6 & 8 are jumped together
- 4 - - - - 20- - - - - - - 6 - - - - 6 and join the 20 on the
- 4 - - - - 20- - - - - - - 8 - - - - 1 other end (both ways)).
-
-
- |--COMPUTER 1--| |--COMPUTER 2--|
- DB9F or DB25F DB25F or DB9F
- pin - - - - 1 - - - - - - - 1 - - - -
- 3 - - - - 2 - - - - - - - 3 - - - - 2
- 2 - - - - 3 - - - - - - - 2 - - - - 3
- 8 - - - - 5 - - - - - - - 20- - - - 4 (As you can see here, pins
- 6 - - - - 6 - - - - - - - 20- - - - 4 5, 6 & 8 are jumped together
- 1 - - - - 8 - - - - - - - 20- - - - 4 and join the 20 on the
- 4 - - - - 20- - - - - - - 5 - - - - 8 other end (both ways)).
- 4 - - - - 20- - - - - - - 6 - - - - 6
- 4 - - - - 20- - - - - - - 8 - - - - 1
-
-
- |--COMPUTER 1--| |--COMPUTER 2--|
- DB9F or DB25F DB25F or DB9F
- pin - - - - 1 - - - - - - - 1 - - - -
- 3 - - - - 2 - - - - - - - 3 - - - - 2
- 2 - - - - 3 - - - - - - - 2 - - - - 3
- 7 - - - - 4 - - - - - - - - - - - (4 & 5 jumpered on one end
- 8 - - - - 5 - - - - - - - - - - - but don't connect thru.)
- - - - - - - - - - - - 4 - - - - 7 (4 & 5 jumpered on one end
- - - - - - - - - - - - 5 - - - - 8 but don't connect thru.)
- 6 - - - - 6 - - - - - - - 20- - - - 4
- 4 - - - - 20- - - - - - - 6 - - - - 6
-
-
-
- The above 9 pin connections were 'figured out' using the 9<>25 pin
- adapters with the following pinouts.
-
- This is the pin outs for adapters from<>to 9<>25 pin cables.
-
- |-- 9F <> 25M --| |-- 25F <> 9M --|
- DB9F or DB25M DB25F or DB9M
- pin 1 - - - - 8 - - - - - - - 1 - - - -
- 2 - - - - 3 - - - 3 - - - - 2 - - - -
- 3 - - - - 2 - - - 2 - - - - 3 - - - -
- 4 - - - - 20- - - 20- - - - 4 - - - -
- 5 - - - - 7 - - - 7 - - - - 5 - - - -
- 6 - - - - 6 - - - - - - - 6 - - - -
- 7 - - - - 4 - - - 4 - - - - 7 - - - -
- 8 - - - - 5 - - - - - - - 8 - - - -
- 9 - - - - 22- - - - - - - 9 - - - -
-
-
-
- Another strange cable I ran into was for a HP Plotter (also applies to
- the HP Paint Jet). A standard serial cable would not work, nor would a
- null modem cable. Before you go out and buy an expensive HP cable try
- making your own from one of the following pinouts.
-
-
- Type I (From a Commercially produced cable/computer store)
-
- |-- COMPUTER --| >>> |--HP Plotter--| (Or Paint Jet)
- *DB9F or DB25F >>> DB25M
- pin 3 - - - - 2 - - - - - - - 3
- 2 - - - - 3 - - - - - - - 2
- 8 - - - - 5 - - - - - - - 20
- - - - - 6 - - - - - - - 20
- 5 - - - - 7 - - - - - - - 7
-
- * The above 9 pin connections were 'figured out' using the 9<>25 pin
- adapters shown above.
-
-
-
- Type II (From a Commercially produced cable/computer store)
-
- |-- COMPUTER --| >>> |--HP Plotter--| (Or Paint Jet)
- DB9F or *DB25F >>> DB25M
- pin 1 - - - - - - - - - - - 4
- 2 - - - - 3 - - - - - - - 2
- 3 - - - - 2 - - - - - - - 3
- 4 - - - - 20- - - - - - - 5
- 4 - - - - 20- - - - - - - 6
- 5 - - - - 7 - - - - - - - 7
- 6 - - - - - - - - - - - 4
- 7 - - - - 4 - - - - - - - 8
- 8 - - - - - - - - - - - 20
-
- * The above 25 pin connections were 'figured out' using the 9<>25 pin
- adapters shown above.
-
-
-
- Type III (From a Computer store made cable in use 12/6/93)
-
- |-- COMPUTER --| >>> |--HP Plotter--| (Or Paint Jet)
- *DB9F or DB25F >>> DB25M
- pin - - - - 1 - - - - - - - 1
- 3 - - - - 2 - - - - - - - 3
- 2 - - - - 3 - - - - - - - 2
- 8 - - - - 5 - - - - - - - 20
- 6 - - - - 6 - - - - - - - 20
- 5 - - - - 7 - - - - - - - 7
- 4 - - - - 20- - - - - - - 5
- 4 - - - - 20- - - - - - - 6
-
- * The above 9 pin connections were 'figured out' using the 9<>25 pin
- adapters shown above.
-
-
-
- Type IV (From a Home made cable in use 12/6/93)
-
- |-- COMPUTER --| >>> |--HP Plotter--| (Or Paint Jet)
- DB9F or *DB25F >>> DB25M
- pin 1 - - - - - - - - - - - 1
- 2 - - - - 3 - - - - - - - 2
- 3 - - - - 2 - - - - - - - 3
- 4 - - - - 20- - - - - - - 5
- 4 - - - - 20- - - - - - - 6
- 5 - - - - 8 - - - - - - - 7
- 6 - - - - 6 - - - - - - - 20
- 8 - - - - 5 - - - - - - - 20
-
-
- * The above 25 pin connections were 'figured out' using the 9<>25 pin
- adapters shown above.
-
-
-
-
- DOS V 6.0 (and Central Point Software's PCTools 8.0 w/ Drive Map 1.0)
- introduced the ability to use a parallel cable (Printer port to Printer
- port cable) to connect two PCs together and share drives. The pin outs
- for the "LINK DOS 6.0" cable follows:
-
-
- |--COMPUTER 1--| |--COMPUTER 2--|
- DB25M DB25M
- pin 2 - - - - - - - - - - - - 15
- 3 - - - - - - - - - - - - 13
- 4 - - - - - - - - - - - - 12
- 5 - - - - - - - - - - - - 10
- 6 - - - - - - - - - - - - 11
- 10- - - - - - - - - - - - 5
- 11- - - - - - - - - - - - 6
- 12- - - - - - - - - - - - 4
- 13- - - - - - - - - - - - 3
- 15- - - - - - - - - - - - 2
-
-
-
-
-
- Most serial port connections only require a few wires to be connected.
- The most common types of connections only require:
-
- |-- COMPUTER --| |-- DEVICE --|
- *DB9F or DB25F DB25M or DB9F*
- pin - - - - 1 - - - - - - - 1 - - - -
- 3 - - - - 2 - - - - - - - 2 - - - - 3
- 2 - - - - 3 - - - - - - - 3 - - - - 2
- 7 - - - - 4 - - - - - - - 4 - - - - 7
- 8 - - - - 5 - - - - - - - 5 - - - - 8
- 6 - - - - 6 - - - - - - - 6 - - - - 6
- 5 - - - - 7 - - - - - - - 7 - - - - 5
- 1 - - - - 8 - - - - - - - 8 - - - - 1
- 4 - - - - 20- - - - - - - 20- - - - 4
-
-
- * The above 9 pin connections were 'figured out' using the 9<>25 pin
- adapters shown above.
-
-
-
- Full pin 25M <> 25F cables have all pins connected straight through:
-
- 25F <> 25M
-
- 1 1
- 2 2
- 3 3
- ... ...
- 23 23
- 24 24
- 25 25
-
- thus making extension cables for either serial or printer cable
- connections.
-
-
-
- Serial cables that have both Male ends or both Female ends are strange.
- The pins are connected from<>to the same pin number on the other end
- (1-1, 2-2, 3-3, ... 25-25) but since the gender is the same on both ends
- these cables are not extension cables but actually CROSS the wires. If
- you were to plug two 'same gender' cables to each other thus making a
- connection like:
-
- 25F > 25F<>25M > 25M
-
- 1 25 25 1
- 2 24 24 2
- 3 23 23 3
- ... ... ... ...
- 23 3 3 23
- 24 2 2 24
- 25 1 1 25
-
- you would have actually created an extension cable.
-
-
-
- I hope this information serves to help some others that were in search of
- answers about computer cables. If you do find any errors in the above
- text please let me know.
-
- Darrell Bivens Silver Bullet BBS (615) 337-9683
- Compiled 12/6/93
-
- *the end*
-