Re: search schematic of serial port of 2C apple

[Rubywand <rubywand@swbell.net>]

Jean-Marie HERIAT writes ...
> 
>  i am searching for the shema of the port
>  serial of the apple 2C
>  i want to use the serial port of the 2C
>  to transfert dsk files with ADT soft
 ....


     This should help:


from Apple II FAQs Resource File R023PINOUTS.TXT
>>


//c (5-pin) serial port and modem cable pinouts
(Most of this is from a post by David Empson.)


     Din 5
 //c Serial Port
 (Female) Socket
 
   5       1
    4     2
       3

The functions are:

1  Handshake Out (nominally DTR)
2  Data Out (TxD)
3  Ground
4  Data In (RxD)
5  Handshake In (nominally DSR)


     Din 5
//c Serial Cable
  (Male) Plug
 
   1       5
    2     4
       3

To wire up a IIc to a simple modem without hardware handshaking, use
the following pinout:

IIc     Modem
DIN-5   Dsub-25M
1 ----- 20 DTR
2 ----- 2  TxD
3 ----- 7  Gnd
4 ----- 3  RxD
5 ----- 6  DSR   (you might want to use pin 8, DCD in some cases)

The IIc cannot do hardware handshaking very well, but this is as close
as you can get:

IIc     Modem
DIN-5   Dsub-25M

1 ----- 4  RTS
2 ----- 2  TxD
3 ----- 7  Gnd
4 ----- 3  RxD
5 ----- 5  CTS

The IIc's handshaking lines have annoying side effects, which cause
problems with hardware handshaking:

1. The "Handshake Out" signal is implemented to mean "I want to send
   data" (the official and original meaning of RTS).  If you turn off
   the output handshake line, the IIc will stop sending data.  For a
   hardware handshaking modem, RTS is supposed to mean "You are allowed
   to send me data" (from the computer's point of view).

   If the computer tells the modem to stop transmitting, the computer
   will also be unable to transmit.  This will reduce the rate at which
   data can be transferred bidirectionally, but doesn't cause any other
   problems.

2. The "Handshake In" signal is implemented to mean "There is receive data
   present" (the official meaning of DCD).  If the incoming handshake line
   is disabled, the IIc will stop receiving data (ignore any data on RxD).
   For a hardware handshaking modem, CTS is supposed to mean "You are
   allowed to send me data" (from the modem's point of view).

   If the modem tells the computer to stop transmitting, the computer will
   also be unable to receive, and will discard any data sent by the modem
   while CTS is not active.  This can cause screen corruption and loss of
   data blocks or acknowledgements during a file transfer, which will
   require retransmission.   It is only likely to be a problem while a
   lot of data is being sent, so is more likely to cause problems
   during a file upload than a download.

   If the comms software is quick enough, it can drop RTS immediately when
   CTS is lowered, which will prevent the modem from sending any more data.

You will need the //c System Utilities disk to set up the serial port
speeds, or a comm program that overrides them anyway.

Max speed is 9600.
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Rubywand