[comp.sys.mac.hardware] Modems galore..

<U35828@uicvm.uic.edu> (06/04/91)

I have a question concerning the Mac in general.  With the appropriate
cabling and software, could I hook up a generic external
Hayes-compatible modem (like the ones for the PC's)?  A local retailer
has a solution, but it is  a rather expensive one.


As I am not a frequent reader on this board, please reply by e-mail.
Thank you.

John D. Serrano (U35828@UICVM.UIC.EDU)

<U35828@uicvm.uic.edu> (06/05/91)

I thank all of those who replied to my question on getting a generic
external Hayes-compatible modem for the Mac.

Here are a few of the replies sent to me:

johnston@minnie.me.udel.edu wrote:

Yes, of course.  Modems are nearly generic.  A serviceable 2400 baud
modem plus mac cable should run you < $100.  Don't pay extra for
software.  Try the free stuff before deciding what features to pay for
...

osborn@ux1.lbl.gov (James R Osborn) wrote:

Yes you definately can (I think).  The Mac uses slightly different
signals on the serial port though.  What this means is that it is
necessary to make a cable which maps the appropriate pins on your modem
to the appropriate ones on the Mac, and I think some of the Mac pins
need to be grounded.  This has something to do with the modem liking
ground and v+ while the mac likes v- and v+.  I know that this could be
determined by an examination of the pinout specs for your modem and the
serial port information for the Mac (which is avaialable in Inside
Macintosh).  I'm not sure whether the Mac ports are all the same either
(ie - Mac+ may not = Mac II, etc.)

gillooly@vixvax.mgi.com (06/05/91)

In "Modems Galore" John D. Serrano asks:

> I have a question concerning the Mac in general.  With the appropriate
> cabling and software, could I hook up a generic external
> Hayes-compatible modem (like the ones for the PC's)?  A local retailer
> has a solution, but it is  a rather expensive one.

You can use any commercial software like "Red Ryder" or "Microphone".  
Fortunatly "Hayes Compatible" means it!!  

To plug into the modem all you need is a Mac DIN8 to Dsubmin25 cable.  
This cable converts the Macintosh round plug to the standard RS-232 
25pin plug.

Hope this helps.

-------------------------------------------------------------
William B. Gillooly Jr.
Applications Specialist

Management Graphics, Inc.                    612-854-1220
1401 East 79th Street                        612-854-6913 FAX
Minneapolis, MN  55425                       gillooly@mgi.com

rkmossm@PacBell.COM (Richard Mossman) (06/05/91)

Well, seeing as how I'm using a Hayes 2400 modem at home with a cable
I bought from Egghead Software and using White Knight; I guess the
answer is "YES".

gillies@m.cs.uiuc.edu (Don Gillies) (06/05/91)

Yes, you need a cable for an external modem (some old ( <= Mac Plus)
mac's have weird DB-25 connections, not the Mini-Din cables of the new
SE's, LC's, and II's).

No, it is not a special cable.  It is simple a modem/printer serial
cable.  A good dealer should sell it to you for $15 to $20.

Suppose you own a macintosh II.  If you are adventurous, you can graft
a power plug onto your monitor plug, using a soldering iron,
electrical tape, and a cheap extension cord.  That way, when you turn
on the Mac II, you can start other device (such as your modem), as
long as you don't overload the Mac II's internal relay.  My
AppleColor monitor doesn't tax the Mac II relay, so I made this graft,
and it works great (for almost 4 years now).

Don Gillies	     |  University of Illinois at Urbana-Champaign
gillies@cs.uiuc.edu  |  Digital Computer Lab, 1304 W. Springfield, Urbana IL

-- 

russotto@eng.umd.edu (Matthew T. Russotto) (06/05/91)

In article <1991Jun5.032332.5076@m.cs.uiuc.edu> gillies@m.cs.uiuc.edu (Don Gillies) writes:
>
>Yes, you need a cable for an external modem (some old ( <= Mac Plus)
>mac's have weird DB-25 connections, not the Mini-Din cables of the new
>SE's, LC's, and II's).

DB-9, actually.

>No, it is not a special cable.  It is simple a modem/printer serial
>cable.  A good dealer should sell it to you for $15 to $20.

WARNING! WARNING! Danger Will Robinson!.... The modem serial cable and the
printer serial cable are DIFFERENT.  A cable made for a DB25 printer (i.e.
the Imagewriter I) makes the mac look like a DCE.  A cable made for a
DB25 modem makes the mac look like a DTE.  You want the MODEM cable.
--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
     .sig under construction, like the rest of this campus.