[comp.sys.mac] Cables for mac

tolson@gatech.edu (John F. Tolson) (08/02/89)

   Could someone tell me what the name of the cable that connects the Mac to
   an external modem.  Also does anyone knoow the name of the cable which is
   used with the program maclink?  

   I have the connections which connect with the mac and a 9 pin female
   connector.  But I need a cable with a 9 pin male connector and a 24 pin
   male connector.  For both the cables.  Does anyone know the pin connection
   for anyone of these two cables.  If you have any information please let me
   know.
				-tolson@gatech

marc@rna.UUCP (Marc Johnson) (08/11/89)

In article <19073@gatech.edu> tolson@gatech.UUCP (John F. Tolson) writes:
>
>   Could someone tell me what the name of the cable that connects the Mac to
>   an external modem.

Assuming you have a Mac +, SE or II, it's just a "Mac Plus to Modem" cable.
This is an 8-pin mini-DIN male to RS232C 25-pin male (DB25) cable.
The pinouts are:

	MAC	DB25P	SIGNAL
	2	5	Clear to Send (CTS)
	3	2	Transmit Data (TD)
	4	7	Ground
	5	3	Receive Data (RD)

Here's a picture of the connectors (NOT the sockets):

           DB8P                             DB25P
	 _______            _________________________________
	/ 6 7 8 \           \ 1 2 3 4 .................. 13 /
	|3 4  5 |            \                             /
	 \ 1 2 /              \ 14 15 ................ 25 /
          _____                ___________________________

You can get one from many sources, but at widely varying prices.  Try
Altex Electronics at 800-5310-5369 (San Antonio).  They have this cable
for $8.95 (#AC-6).  If you have a Mac 512, you'll need their cable #AC-8.

> ...   Also does anyone knoow the name of the cable which is
>   used with the program maclink?  
>
>   I have the connections which connect with the mac and a 9 pin female
>   connector.  But I need a cable with a 9 pin male connector and a 24 pin
>   male connector.  For both the cables.  Does anyone know the pin connection
>   for anyone of these two cables.  If you have any information please let me
>   know.
>				-tolson@gatech

Here you need to be more specific.  Are you trying to connect to a PC/XT or
an AT?  The XT has a 25-pin serial port, while the AT has the newer 9-pin
connector.  Essentially, you want the Mac's "Transmit Data" (TD) line to
connect to the PC's "Receive Data" (RD) line, and vice versa.  You can connect
the cable just mentioned to a cable that has a 25-pin female on one end and
a 9-pin female on the other (if it's an AT) or a 25-pin on that end (if an XT).
Here are the cable pinouts for both cases:

9-pin female (DE9S)		25-pin female (DB25S)
  AT end			Connects to Mac modem cable
--------------------------------------------------------
	1  CD-Carrier Detect		8  CD
	2* RD-Receive Data		3* TD
	3* TD-Transmit Data		2* RD
	4  DTR-Data Term Ready		20 DTR
	5* Ground			7* Ground
	6  DSR-Data Set Ready		6  DSR
	7  RTS-Request to Send		4  RTS
	8* CTS-Clear to Send		5* CTS
	9  RI-Ring Indicator		22 RI

Only the lines with * really need to be connected.

If you're going to an XT with a 25-pin connector, it's even easier:
just connect pins 7 and 5 straight thru, and criss-cross pins 2 and 3
(i.e., pin 2 on one end connects to pin 3 on the other, and vice versa.)
This is called a "null modem" cable.  You should also be able to get this
one from Altex and other sources (try also National Computer Associates,
916-441-1568 - Sacramento).

Good luck!

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
= Marc Johnson			    BITNET:   rna!marc@rockvax.bitnet         =
= Rockefeller Univ. Neurobiology    UUCP:     ...cmcl2!rna!marc               =
= New York City                     INTERNET: marc%rna@rocky2.rockefeller.edu =
=                                             (129.85.2.1)                    =
=                                                                             =
= "Gimme the beat boys and free my soul, I wanna get lost in your rock & roll =
=                           ...and drift away"                                =
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=