[comp.sys.mac.hardware] Hardware Handshaking on Mac Plus

sethcohn@alchemy.tcnet.ithaca.ny.us (seth cohn) (03/18/91)

ok, HOW can you do Hardware handshaking on a mac plus?
(or on a Classic, LC, or Si)  None of these has Pin 7
(known as GPi or general Purpose input)  hooked up
(apple got cheap and figured it wasn't neccessary)
thus you can hook up hardware handshaking but you lose carrier detect
(which is not acceptable!!!)
Can you use pin 8 - which is the extra receive pin
for carrier detect if the software is right????
if not, any other way???

thanks in advance,
Seth

Seth Cohn, Service Tech.  607-273-2815 voice 607-272-7002 BBS
All things posted are opinions by me, of me, for me, or to me.
And another thing..........I'm not sure you're real.

russotto@eng.umd.edu (Matthew T. Russotto) (03/18/91)

In article <78Ryy2w162w@alchemy.tcnet.ithaca.ny.us> sethcohn@alchemy.tcnet.ithaca.ny.us (seth cohn) writes:
>ok, HOW can you do Hardware handshaking on a mac plus?
>(or on a Classic, LC, or Si)  None of these has Pin 7
>(known as GPi or general Purpose input)  hooked up
>(apple got cheap and figured it wasn't neccessary)
>thus you can hook up hardware handshaking but you lose carrier detect
>(which is not acceptable!!!)
>Can you use pin 8 - which is the extra receive pin
>for carrier detect if the software is right????
>if not, any other way???

No, you can't use the RxD+ line.  What software do you have that gets CD on
Pin 7?  And why would you need CD if you aren't doing a BBS?
BTW, the SE, SE/30, IIx, II, IIcx, IIfx, and IIci all have pin 7--
are you sure the Classic, LC, and SI don't?
--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
     .sig under construction, like the rest of this campus.
I mine 600 wells, and whaddo I get?  Another day older and deeper in debt!
	--- Saddam Hussein.

sethcohn@alchemy.tcnet.ithaca.ny.us (seth cohn) (03/19/91)

russotto@eng.umd.edu (Matthew T. Russotto) writes:

> In article <78Ryy2w162w@alchemy.tcnet.ithaca.ny.us> sethcohn@alchemy.tcnet.it
> >ok, HOW can you do Hardware handshaking on a mac plus?
> >(or on a Classic, LC, or Si)  None of these has Pin 7
> >(known as GPi or general Purpose input)  hooked up
> >(apple got cheap and figured it wasn't neccessary)
> >thus you can hook up hardware handshaking but you lose carrier detect
> >(which is not acceptable!!!)
> >Can you use pin 8 - which is the extra receive pin
> >for carrier detect if the software is right????
> >if not, any other way???
> 
> No, you can't use the RxD+ line.  What software do you have that gets CD on
> Pin 7?  And why would you need CD if you aren't doing a BBS?
> BTW, the SE, SE/30, IIx, II, IIcx, IIfx, and IIci all have pin 7--
> are you sure the Classic, LC, and SI don't?
> --
> Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
> I mine 600 wells, and whaddo I get?  Another day older and deeper in debt!

1) Yes, I AM running a bbs, so I DO need carrier detect (sorry that 
wasn't clear in the first post)
2) Yes, Pin 7 is used for carrier detect.  WHY can't you use pin 8?
    it's currently grounded.
3) according to APPLE specs (as of the latest service tech manual i just 
got - "Not connected on Macintosh Plus, classic, LC, or IISi"
Hmm, anybody got any ideas?  Handshaking is important for REAL speed
I'm going to be using a US Robotics HST DS with v32bis.

Seth
Your Friendly Tech, what the heck.


Seth Cohn, Service Tech.  607-273-2815 voice 607-272-7002 BBS
All things posted are opinions by me, of me, for me, or to me.
And another thing..........I'm not sure you're real.

russotto@eng.umd.edu (Matthew T. Russotto) (03/20/91)

In article <D381y3w162w@alchemy.tcnet.ithaca.ny.us> sethcohn@alchemy.tcnet.ithaca.ny.us (seth cohn) writes:
>
>2) Yes, Pin 7 is used for carrier detect.  WHY can't you use pin 8?
>    it's currently grounded.

Because Pin 8 (if it is RxD+ -- I don't have a manual here to tell me) is
one half of a differential reciever.  Your mac can see whether it is getting
a '0' or a '1' by checking to see whether the voltage is higher on the
RxD+ line or RxD- line.  They are not independant inputs.

>3) according to APPLE specs (as of the latest service tech manual i just 
>got - "Not connected on Macintosh Plus, classic, LC, or IISi"

>Hmm, anybody got any ideas?  Handshaking is important for REAL speed
>I'm going to be using a US Robotics HST DS with v32bis.

Yep, you aren't going to be getting any 3200 cps transfers.  If you can modify
the program, you can change it to use the CTS line on the OTHER port.  If you
can't, you are SOL.
--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
     .sig under construction, like the rest of this campus.

Mark.Hollingsworth@f1.n354.z1.FIDONET.ORG (Mark Hollingsworth) (03/25/91)

Seth Cohn writes;
 
>ok, HOW can you do Hardware handshaking on a mac plus?
>(or on a Classic, LC, or Si)  None of these has Pin 7
>(known as GPi or general Purpose input)  hooked up
>(apple got cheap and figured it wasn't neccessary) thus
>you can hook up hardware handshaking but you lose
>carrier detect (which is not acceptable!!!) Can you use
>pin 8 - which is the extra receive pin for carrier
>detect if the software is right???? if not, any other
>way???
 
>thanks in advance, Seth
 
 
 
If you are not running a BBS, you really don't need the
carrier dectect. If you are, then you are correct (at 
least as far as I have been able to find out) you can't
do both on the plus.
Here is the proper pin diagram for Hardware Handshake 
cable:
 
 
Mac                   DB25
 
1----------------------4
2----------------------5
3----------------------2 
4----------------------7
5----------------------3 
6-------------unconnected
7-------------      "" 
8---------------    ""
 
Hardware Handshake modem cable
 
If you are using a US Robotics HST modem,
then use the following NRam settings:
 
USRobotics Courier 14400 HST NRAM Settings...
 
   DIAL=TONE   B1  F1  M1  X7
   BAUD=38400  PARITY=N  WORDLEN=8
 
   &A3  &B1  &G0  &H1  &I0  &J0  &K3  &L0
   &M4  &N0  &P0  &R2  &S0  &X0  &Y1
 
   S02=043   S03=013   S04=010   S05=008
   S06=002   S07=060   S08=002   S09=006
   S10=007   S11=070   S12=050   S13=000
   S15=000   S19=002   S21=010   S22=017
   S23=019   S24=150   S26=000   S27=000
   S28=008   S38=000
 
 
Dip switch settings
 
1--down    2--up   3---down  4--up  5--down
6--down   7--up   8--down  9--down  10--up
 
 



--  
Mark Hollingsworth - via FidoNet node 1:105/14
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