

CTS/RTS hardware handshake for GS

   Mini-Din 8                      DB-25 (RS-232 Male)

  Female   Male           01 02 03 04 05 06 07 08 09 10 11 12 13
                           14 15 16 17 18 19 20 21 22 23 24 25
  8 7 6   6 7 8
  5 4 3   3 4 5                    DB-25 (RS-232 Female)
   2 1     1 2
                          13 12 11 10 09 08 07 06 05 04 03 02 01
                           25 24 23 22 21 20 19 18 17 16 15 14

DIN-8    DB-25     Signal Discription

  3        2        TD  (Transmit Data)
  5        3        RD  (Receive Data)
  4,8      7        GND (Ground)
  2        5        CTS (Clear to Send)
  1        4,20     RTS (Ready to Send) (20 = Data Terminal Ready, DTR)
  7        8        DCD (Data Carrier Dectect)


 The wiring for a GS-serial-port and a modem,is as follows:
 
 
 
 GS serial port                          Modem
 
       1....>>...........DTR..............20
 
       2.................DSR......<<.......6
 
       3....>>...........TxD...............2
 
       4.................GND...............7
 
       5.................RxD......<<.......3
 
       7.................DCD......<<.......8
 
 1.The arrows mark the direction of the signal (i.e,DTR is output from the
 modem into the computer etc,).
 
 2.The numbers for on the GS port column assume the following numbering on the
 connector:
 
         +++#  #+++
      +     #__#    +
     +   8   7   6    +
    +                  +
    +   5   4     3    +
    +                  +
     +     2    1     +
       ###        ###
        +#        #+
            ++++
 
 3.The numbers on the modem column assume the standart DB-25 RS232 connector.
 
 As to 'minimal connection',I don't think there are many modems that would
 compromise on DTR.Anyhow,lack of DSR and DCD is usualy more tolerable.
 
 TxD+/TxD- and  RxD+/RxD- is part of the glorious RS 422 concept,and more
 accurately,of a method called 'differencial signal'.In this method,for each
 of the Receive and Transmit signals,one wire carries the signal just as it
 would on RS 232,and a second wire carries the first's inverse polarity.(Thus
 the couples xD+/xD-).Now,the receiving device compares the xD+ to it's
 inversed partner.If xD+ is higher than xD-,the receiving device reads 'high',
 if it's lower,the device reads 'low'.What you get is a speed considerably
 higher than on RS 232,and a connection much more emmune to noises.
 
 You'll have to work out the appropriate Control-Panel configuration according
 to the modem and software you use.
 
                                     Yoram Ney
                              Hebrew University,Jerusalem
                                 Bitnet:NEY7@HBUNOS
From pro-freedom!pro-ren!pro-applejacks!terry%clark.edu@mail4.engin.umich.edu Wed Jun 16 05:21:23 1993
Received: from srvr2.engin.umich.edu by mail4.engin.umich.edu (5.64/1.35)
	id 6090306cf.0017b7e; Wed, 16 Jun 93 05:21:19 -0400
Received: from crash.cts.com by srvr2.engin.umich.edu (5.64/1.35)
	id AA18626; Wed, 16 Jun 93 05:21:16 -0400
Received: from clark.edu by crash.cts.com with smtp
	(Smail3.1.28.1 #15) id m0o5tg8-00005wC; Wed, 16 Jun 93 02:21 PDT
Received: by clark.edu (Smail3.1.28.1 #1)
	id m0o5tcF-0000ZBC; Wed, 16 Jun 93 02:17 PDT
Received: by pro-freedom.van.wa.us (sendmail 2.3.1 7jun93)
	id <fg07410@pro-freedom.van.wa.us>; Wed, 16 Jun 93 02:03 PDT
Received: by pro-ren.cts.com (sendmail 2.3 24mar92)
	id <fg09982@pro-ren.cts.com>; Wed, 16 Jun 93 02:46 CDT
Received: by pro-applejacks.cts.com (sendmail 2.3 24mar92)
	id <ff78998@pro-applejacks.cts.com>; Tue, 15 Jun 93 21:56 CDT
Message-Id: <ff78998@pro-applejacks.cts.com>
Date: Tue, 15 Jun 93 21:48:44 CDT
From: terry@pro-applejacks.cts.com (Terry DeSmet)
X-Mailer: Mail (1.7 20feb92)
To: dmag@engin.umich.edu
Subject: Re: FAQ/IWII with PC
Status: R

I'm interested in using my IWII on a pc clone because I have a GS *and* a
PC.  I'd also like to use my Panasonic 2123 printer with the GS, so I'd
like a diagram of the best way to hook up a PC and a GS and share the
printers.
I have the PT3 manual, and it tells the pinouts for a cable, but I don't
want to get into the cable construction business. I want to buy one that I
KNOW will work before I order it.  I don't remember what all I said in my
previous mail, but I've heard that a Mac modem cable will work, and also
that it WON'T work with a GS.   Here's a couple of messages I saved
concerning the wiring.

 
CS-ID: #7206.apple/apple.corp@pro-applejacks, 2907 chars
Date: 23 Feb 92 12:23:32 GMT
From: t.captain@bluemoon.rn.com (Tc Wilson)
Subject: Re: IIGS Hardare Handshaking Serial Cables -
Organization: Blue Moon BBS ((614) 868-998[024])
 
>   Does anyone out there in Net.Land have the pin connections to use for a
> CTS/RTS handshake compatible serial cable for the GS?
 
[Note: the file assumes an USR is in use, but any flow-control-compatible
modem will work - you may have to add commands to the init string in order
to
TELL the modem that it can now flow-control]
 
In your ControlPanel, you MUST have Modem: DSR/DTR Handshake to YES (the
checkmarked default). Otherwise, the firmware will NOT flow-control the
modem, and the end user will get stomped on once the 1.5k buffer in the
USR fills.
 
Now, for the cable. The following pins must be connected in the WAY THAT
THIS
SAYS for this to work. This is the NORMAL setup for MOST "Mac" modem
cables,
minus the carrier detect.
 
GS side:                        RS232 side:
 1 (HSKo)                         4 (RTS)
 2 (HSKi)                         5 (CTS)
 3 (TxD-)                         2 (TD)
 4 (SG)                           7 (SG)
 5 (RxD-)                         3 (RD)
 6 (TxD+)
 7 (GPi)                          8 (CD) -or- 6 (DSR), depending on modem
 8 (RxD+)
 
Now, if you don't have the correct cable, my suggestion is this:
 
Go to Radio Shack, and spend $9.95 for a RS232 JUMPER BOX (part #276-1403).
This little doodad will allow you to re-wire the connections between the
modem and the plug on the end of the cable (thus, re-wiring the cable).
MUCH
easier than slicing and dicing the cable.
 
 
CS-ID: #7228.apple/apple.corp@pro-applejacks, 1533 chars
Date: Sun, 23 Feb 1992 02:23:00 -0500
From: White.Wolf@f438.n109.z1.fidonet.org (White Wolf)
Subject: IIGS Hardare Handshaking
Newsgroups: comp.sys.apple2
Message-ID: <698936427.F00001@blkcat.UUCP>
Sender: Uucp@blkcat.UUCP
 
CM|   Does anyone out there in Net.Land have the pin connections to use
CM| for a CTS/RTS handshake compatible serial cable for the GS?  I am
CM| currently using one that I hacked together based on the diagram in
CM| the Hardware Ref. for the GS, but some programs tend to barf quite
CM| badly on it, 'cause it doesn't support the hardware handshakes.
 
Males have pins, Females have holes
 
   Mini-Din 8                      DB-25 (RS-232 Male)
 
  Female   Male           01 02 03 04 05 06 07 08 09 10 11 12 13
                           14 15 16 17 18 19 20 21 22 23 24 25
  8 7 6   6 7 8
  5 4 3   3 4 5                    DB-25 (RS-232 Female)
   2 1     1 2
                          13 12 11 10 09 08 07 06 05 04 03 02 01
                           25 24 23 22 21 20 19 18 17 16 15 14
 
DIN-8    DB-25     Signal Discription
 
  3        2        TD  (Transmit Data)
  5        3        RD  (Receive Data)
  4,8      7        GND (Ground)
  2        5        CTS (Clear to Send)
  1        4,20     RTS (Ready to Send) (20 = Data Terminal Ready, DTR)
  7        8        DCD (Data Carrier Detect)
 

--------------------------------------
ProLine:  terry@pro-applejacks
Internet: terry@pro-applejacks.cts.com
UUCP:     crash!pro-applejacks!terry

