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Re: rewire Seiko Datagraph 2001 cable for Apple // c Modem Port
Marc wrote:
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)
The mini-phone plug provides ground, TxD, and RxD. No hardware
handshaking at all.
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 ?
Yes, since the //c serial ports use standard signalling.
Thank you in advance for your help, in particular Apple // serial cable
experts...
The problem you will have is that the Seiko software for the Apple
expects to "bit bang" a serial port, not use an actual one.
It will be necessary to reverse-engineer the software to find the
low-level serial port simulation, and then, hopefully, replace it
with a routine to use the //c serial link (6551 UART).
You don't have the option of using the unmodified software, since
the game port cable uses both a pushbutton input and an annunciator
output, and the //c does not have annunciator outputs.
I wonder about any Y2K issues with this watch/software?
-michael
Music synthesis for 8-bit Apple II's!
Home page: http://members.aol.com/MJMahon/
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