Re: TI-H: TI <--?--> I2C


[Prev][Next][Index][Thread]

Re: TI-H: TI <--?--> I2C




Yes, but you said this too:
>>>>There is no MBus.  Under the restrictions made by Philips the standard
>>>>must be called 'I2C' and have atleast one authorized I2C device on the
>>>>network, none of which include a TI calculator.


At 07:55 AM 10/17/98 -0800, you wrote:
>
>>Go to www.clinet.fi/~ozone/i2c for information on the Mbus and I2C systems.
>> Grant is right in that you only can legally use the I2C protocol if you
>>have a I2C device made by Phillips in the network.  However, its not likely
>>that Phillips is going to come to your house and investigate your
>>calculaotr for fear that it may use the I2C protocol.
>
>I didn't say there was no MBus.  I said:
>
>>>>The MBus isn't a protocall.
>>>>
>>>>There is no MBus Hub.
>
>
>>Back to your initial question, yes, two calculators using a ti-cable can
>>use the i2c protocol. When grant said there was no MBus, he meant that
>>there was no MBus protocol.  While this is not entirely true (Osma did
>>modify the I2C protocol slightly to better accomadate a calculator
>>network), the MBus system is more like a bunch of routines which enable you
>>to use the I2C protocol from your calculator over the link port.
>
>The only modification he did was slow the speed of transfers a little.
>That isn't modifying the code since all I2C chips can do that.  Its not I2C
>if he modified it.  You'd be surprized how strict the I2C rules are.  : \

I've looked at them.  What he did was add a "software" level of the
protocol when going between two calculators.  It sends the address byte,
followed by the protocol-id or whatever he calls it, which determines which
program that is using the network should pick up the message.  When sending
data to a real i2c device, it is sent in "raw mode"


Follow-Ups: References: