Re: TI-H: Mac Link
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Re: TI-H: Mac Link
From: pepsi <pepsi@chicagonet.net>
>>>From: Dan <danti@applecyber.dyndns.com>
>>>The three wires are Data (red), Clock (white), and ground... it is
>>serial... so if you wanna make a link... do some research... actually,
lots
>>>of it...
>>
>>
>>The names Data and Clock are misleading, they would be more
>>properly called "1" and "0", due to the way the TI uses them for
>>transfering data. Who came up with 'Data' and 'Clock' anyway?
>
>hmm.... now this thing about the Clock not being Clock got me confused...
>does the calculator control the clock or not?
There is no 'clock' line. The red and white wires are both used to transmit
data and ack bits. If the calc needs to transmit a '1' bit, it pulls the
Red
wire to ground, the other calc sees that wire go to ground, and acks the
bit by pulling the White wire to ground. Both calcs then clear the lines,
and the sending calc sends the next bit. If it is a '0' bit, it pulls the
White
wire to ground, and the receiving calc pulls the red wire to ground to
ack.
I may have mixed up the wire colors there, I always have to check to
be sure I have the right colors.
Either way, thats why I say they would be called something like '0'
and '1' instead of 'Clock' and 'Data', because there is no clock,
and data is transmitted on both wires.
>if not, what speed should i use? but it seems like the calculator does
>control the clock as speeds seem variable for people
When receiving just ack the bits when they come in and then clear
the lines. You might wait for the sending wire to be released before
releasing your wire, but if you are using windows that probably won't
be a problem, depending on your system and the speed of the calculator,
you probably won't be able to clear the line faster than the calc can
recognize the ack anyway.
Try it both ways, see if the calc will raise the sending line with your
ack line down, if so you can probably do it that way to provide more
reliable communication. I don't really know for sure tho, been a long
time since I did anything with it.
DK
"I refuse to engage in structural engineering discussion of a banana over
breakfast."
-- Aaron Marsh, Swarthmore '98
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