Re: apple //c connector !!

[dempson@actrix.gen.nz (David Empson)]

KCUF airmaster <airmaster@KCUF.org> wrote:

> On Mon, 17 Nov 1997 22:52:10 +0200, Aviad Offer <seaman@netvision.net.il>
> wrote:
> 
> >Does any one know's how to connect the serial out put (modem) of
> >my //c to imb serial ..
> >I made my own cable but it didn't work ...
> >apple                            Ibm
> >    5 pin                            25 pin
> >-----------                        ------------
> >    1                                    1
> >    2                                    2
> >    3                                    3
> >    4                                    4
> >    5                                    5
> >
> >and it didn't work, What could be the problem.
> >I tryed to connect into com2 and send with communication program an
> >ascii file (with the in#2 command in apple //c).
> >not a signal ... nothing !
> 
> Sounds like the cable to me, unless the port is trashed.  My only (useful)
> comment involves Apple //c's made earlier than a certain point which had an
> inability to communicate via serial ports; this, like many other things, is in
> one of the FAQs floating around here.

Eh?  The PC end connections are _totally_ wrong.

The correct pinout is debatable, as it depends on what the software at
each end expects to do with the flow control signals.  A typical
IIc-to-PC cable would be as follows.

IIc (DIN-5) - looking at the back of the computer

5       1
 4     2
    3

1  DTR (RTS)
2  TxD
3  Gnd
4  RxD
5  DSR (DCD)


IIc end           PC end (DB-25)
1 DTR ----------- 5 CTS
2 TxD ----------- 3 RxD
3 Gnd ----------- 7 Gnd
4 RxD ----------- 2 TxD
5 DSR ----------- 4 RTS

The IIc hardware is not able to transmit while its outgoing flow control
signal is off.  Similarly, it is not able to receive while its incoming
flow control signal is off.  To avoid problems, disable hardware
handshaking at both ends.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand