rewire Seiko Datagraph 2001 cable for Apple // c Modem Port

["Marc" <marc.coppey@vrt.be>]

Hello,

I  bought an old Seiko datagraph watch UC 2001, that communicates with
the older style Apple II gameport.
The cable comes with a 1/8" audio connector at one end and a 16 pin
gameport connector at the other side.  As to communicate with the Apple
//c serial modem port I should change the 16 pin connector for a 5 pin
serial Din connector:
I can e-mail a scheme as JPG- and/or PDF, for whom can or wants to help
me. Can someone advice me about my presumptions and the following
questions:

1. concerning the connection cable from the UC-2301 to a serial Apple
//c connector. Am I correct to suppose that only four of the five pins
of this connector should be used ?

- Ring to Pin 2 (TxD),
- Base to Pin 3 (GND)
- Tip to Pin 5 (DSR) or Pin 1 (DTR)?, and to Pin 4 (RxD)

2. In the serial solution for connecting to a Standard PC RS232 port
(DSUB9) a transistor was inserted: in order for the PC serial port to
understand the signal, it needed to be inverted. The transistor does
that. Should that be also the case for the Apple //c modem port ?

Thank you in advance for your help, in particular Apple // serial cable
experts...

Marc