Re: Apple //e to PC Null modem cable pinout

[phoenyx <phoenyx@texas.net>]

Gary Kratochvil wrote:

> Please respond by email as well as the group. My news provider has been
> very poor the last week.
>
> I have an Apple //e with Super Serial Card and need to go to my 9 pin
> serial port on my PC. I have the following information from Rubywand
> from an earlier message.
>
> >      According to the "Modem Works" manual, there is a special modem cable
> > recommended for connecting to a Super Serial Card to get hardware handshaking flow
> > control:
> >
> > SSC side      Modem side
> > 25-pin Dsub   25-pin Male Dsub
> >
> >    2 -------> 2
> >    3 <------- 3
> >    4 -------> 4
> >    5 & 8 <--- 5
> >    6 <------- 8
> >    7 <------> 7
> >    20 ------> 20
>
> I do have the SSC card for the Apple so I'm assuming I use the pinout
> above and the "Modem side" is my PC. I have a 9 pin serial port on the
> PC. I also have a 25 to 9 pin adapter to use. Does "5 & 8 <--- 5" mean I
> need to jump 5 & 8 to 5? I've read the info in the FAQ's about the dip
> switch settings for the SSC. On SW1 and SW2 there is 1-8 on one side of
> the switch and "open" on the other. Does the dip switch set to "open"
> mean on? What transfer rate is max? I don't think I have an accelerator
> chip so am I maxed at 4800?
>
> I also have pinout information for a 25 to 9 pin cable from Teodor
> Angeloff who wrote the Apple Oasis program. His suggestion for the cable
> construction is below. I don't understand some of the symbols used. Can
> someone please clarify?
>
> Here is the Null Modem connection:
>
> PC  (DB-9)                   Apple*(DB-25)
>
>  RxD (2) ---------------------- TxD (2)
>  TxD (3) ---------------------- RxD (3)
>  GND (5) ---------------------- GND (7)
>
> I understand the part above but not the part below.
>
>  RTS (7) --\                /-- RTS (4)
>  CTS (8) --/                \-- CTS (5)
>
>  CD  (1) --\                /-- DSR (6)
>  DSR (6) --+                +-- DTR (20)
>  DTR (4) --/                \-- CD  (8)
>
> I don't understand the "--\ /-- --+ +--" notations. Does this mean
> something other than connecting pin 7 to pin 4 in the first line?
>
> Thank you for your time,
>
> Gary

On Teodor's cable it is:
    pin 2 to 2  between connectors
    pin 3 to 3  between connectors
    pin 5 to 7  between connectors

    pin 7&8 shorted together on PC connector
    pin 1,6,4 shorted together on PC connector

    pin 4&5 shorted together on Apple connector
    pin 6,20,8 shorted together on Apple connector

Basically you are fooling the handshaking routines built into the compters. Most simple
programs
don't even use the handshake. For instance, ADT.

On the cable from Rubywand. Yes, you are shorting those wires,  It is easiest to hook 5
to 8
then 8 to 5 on the other connector.  This cable does not fool the hardware handshake
routines
and is better for PC to Apple terminal programs and transfer protocals such as Zmodem.

BluPhoenyx