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4 total messages Started by GuestRA Thu, 16 Oct 1986 00:29
Modems on a Mac Plus
#7626
Author: GuestRA
Date: Thu, 16 Oct 1986 00:29
6 lines
733 bytes
Has anyone connected a non-Apple modem to the modem port of a Macintosh
Plus?  I would imagine someone has....  What connections did you use to make
it work?  Did you have any trouble?
    Thanks,
	Ron Guest
	ihnp4!druhi!cosmos
Re: Modems on a Mac Plus
#7687
Author: Ben Cranston
Date: Fri, 17 Oct 1986 18:42
90 lines
4517 bytes
In article <1144@druhi.UUCP> cosmos@druhi.UUCP (Ron Guest) writes:

> Has anyone connected a non-Apple modem to the modem port of a Macintosh
> Plus?  I would imagine someone has....  What connections did you use to make
> it work?  Did you have any trouble?

I couldn't find the 8 pin Din males anywhere, so I decided to use the
adapter cable that came with the Mac + and got myself some DB9 males
and made up these two cables:

For connecting Mac to Modem or other DCE-type Female:

  DB9 Male                              DB25 MALE

       GROUND 3 O------+----------------O 7  GROUND
  XMIT DATA + 4 O-x    )
  XMIT DATA - 5 O------)----------------O 2  XMIT DATA
HANDSHAKE OUT 6 O---+--)----------------O 20 DATA TERMINAL READY
HANDSHAKE  IN 7 O---+  |            +---O 4  REQUEST TO SEND
  RECV DATA + 8 O------+            +---O 5  CLEAR TO SEND
  RECV DATA - 9 O-----------------------O 3  RECV DATA

This works with our three-wire Gandalf network inhouse and with a Courier
modem at home.  The Mac is the new RS-422 (?) balanced protocol, and the
old RS-232 had inverted data, so the DATA - goes across and the DATA +
gets grounded to complete the circuit.  Do NOT ground XMIT + !

For connecting Mac to Terminal or other DTE-type Male:

  DB9 Male                              DB25 FEMALE
       GROUND 3 O------+----------------O 7  GROUND
  XMIT DATA + 4 O-x    |
  XMIT DATA - 5 O------)----------------O 3  RECV DATA
HANDSHAKE OUT 6 O-x    |
HANDSHAKE  IN 7 O------)----------------O 20 DTR
  RECV DATA + 8 O------+
  RECV DATA - 9 O-----------------------O 2  XMIT DATA

This works with an H19 at home and a Volker Craig 4404 at work.  If your
device is persnickety it might want Carrier Detect on pin 8, if so then
connect 8 to 20 at the DB25 end (so DTR drives it).  One might also have
to connect pins 4 and 5 (RTS-CTS) together at the DB25 end to make some
devices happy.

Other than that, get a breakout box and read the specs, and if it does
not work then don't leave it connected long enough to get hot...

------------------------------------------------------------
Several months later:
------------------------------------------------------------

On old MACs the DTR line was held high by hardware.  On the Mac Plus there
is a driver for the DTR line.  SOME of the older terminal programs don't
have the code to drive DTR high, and SOME modems require DTR.  If at ALL
possible, set your modem up to IGNORE DTR and stay on all the time.  This
fixes a multitude of problems...

DIN 8 connectors are available.  They're just a @#$%^&*( to work with.  It
takes me half a day to make one cable, and I ruin 40% of the connectors I
try (and at $3.75 a connector that ain't cheap).  The only way I have found
to do this is to hand strip a few inches of Slit-N-Wrap wire, CAREFULLY
solder that to the connector pins (and HEAT SINK the pin too), then solder
the other end of the Slit-N-Wrap wire to the cable proper.  Really tedious.

Macintosh Plus to modem (or other DCE device):

  DIN 8 Male                            DB25 MALE

       GROUND 4 O--+--------------------O 7  GROUND
  RECV DATA + 8 O--+
  XMIT DATA - 3 O-----------------------O 2  TD
HANDSHAKE OUT 1 O--+
HANDSHAKE  IN 2 O--+--------------------O 20 DTR
  RECV DATA - 5 O-----------------------O 3  RD

Macintosh Plus to terminal (or other DTE device):

  DIN 8 Male                            DB25 FEMALE

       GROUND 4 O--+--------------------O 7 GROUND
  RECV DATA + 8 O--+
  XMIT DATA - 3 O-----------------------O 3  RD
HANDSHAKE  IN 2 O-----------------------O 20 DTR
  RECV DATA - 5 O-----------------------O 2  TD

"A boat anchor doesn't have a BIOS..."  :-)
-- 
                    umd5.UUCP    <= {seismo!umcp-cs,ihnp4!rlgvax}!cvl!umd5!zben
Ben Cranston zben @ umd2.UMD.EDU    Kingdom of Merryland Sperrows 1100/92
                    umd2.BITNET     "via HASP with RSCS"
Re: Modems on a Mac Plus
#7688
Author: Tim Hazen
Date: Sat, 18 Oct 1986 23:55
16 lines
1281 bytes
In article <1144@druhi.UUCP>, cosmos@druhi.UUCP (GuestRA) writes:
> Has anyone connected a non-Apple modem to the modem port of a Macintosh
> Plus?  I would imagine someone has....  What connections did you use to make
> it work?  Did you have any trouble?
>     Thanks,
> 	Ron Guest
> 	ihnp4!druhi!cosmos

All I did was buy an 'Apple //e Printer Cable.'  What it is is a DB-25 
connector <-> DIN 8 (on a //e, it connects from the DB-25 Super Serial Card
port to the ImageWriter II).  It works fine, no null modem needed or anything.
I got the '//e printer cable' for $22 from my dealer; ComputerWare sells
an equivalent for around $14, I think ( I needed mine in a hurry).

Tim Hazen   {seismo,ihnp4,allegra,topaz,harvard}!uwvax!puff!uhura!scotty!hazen
						uhura!scotty!hazen@puff.wisc.edu
Re: Modems on a Mac Plus
#7747
Author: David Phillip Oster;Tolman 4527;...
Date: Thu, 23 Oct 1986 04:55
16 lines
1404 bytes
I'm talking to you now on a Hayes modem connected to my macplus.
The cable is
1.) a min-8 to DIN-9 (old mac standard) adapter  connected to
2.) a radio shack joystick extension cable connected to
3.) a 25 pin connector soldered in the following pattern:
    2 brown  (joysitck pin 5)
    3 white  (joystick pin 9)
  +-4 black  (joystick pin 7)
  | 7 both gray and orange (joystick pins 3, and 8)
  +-20
   Whenever I solder up a cable, I write the wiring diagram on the cable
   shield, so I can answer questions like this, without having to take the
   cable apart!
--- David Phillip Oster		-- "We live in a Global Village."
Arpa: oster@lapis.berkeley.edu  --
Uucp: ucbvax!ucblapis!oster     -- "You are Number Six."
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