Re: LZ: RT-Link: Has anybody gotten it to work?
> At 09:39 AM 10/15/96 -0600, C Kuethe wrote:
> >On Tue, 15 Oct 1996, Mel Tsai wrote:
> >> Actually, HP designed it that way on purpose. That way you can't send
> >> answers to a math test across the room!
> I know a few engineers who use to cheat on tests (not just math), in just
> this way. They will transmit across the room.
> >> Like you said, sending data will be prone to a host of errors. I
> >> doubt you'll be able to use the regular TI-85 link program to send
> >> data (unless it's a very short distance). Some sort of custom zshell
> >> send/receive program will have to be written.
> Yes, that is what's needed. I'm working on an IR link, but I need help
> with the programming.
> We need two peices of software to make this work, 1) A link program for the
> pc that uses standard RS-232 tx/rx lines; 2)A link program on the calc that
> uses one line as both tx/rx, or uses both lines as one tx and the other rx.
> The problem that the calc runs into, when we try to connect any asynchronous
> device (RT-,Ir-, or modem), is that the calc uses the second line of the
> link port as some sort of clock line. Therefore, the calc acts like a
> synchonous device.
> I've already begun working on the hardware side. I am looking into two
> different Ir transceiver devices, one is programable, the other is not. The
> first could be programmed as a TV remote or to act as any Ir type device.
> This device, however, requires cofiguration code to be transfered to the
> chip before it will operate. The other chip is an all in-one device; the
> tx/rx Ir LEDs are built in. It communicates in the Ir-DATA standard mode (1
> in, 1 out). Both devices are half duplex. Depending the LEDs selected, the
> range could stretch out to 35-50 ft. Both devices are small enough to be
> mounted inside the calc case and run off the calcs batteries.
> Would anyone one like to help with this project?
Go read linkprot.txt fisrt before embarking, then you'll have a
decent idea of how teh ti-85 uses teh link port...
also remember that asyncronous protcols are going to be difficult
with the ti-85 because of it's variable speed.
Rob Taylor MAIL - mailto:email@example.com
WEB - http://www.u-net.com/~rtaylor/