Re: TI-H: Linking Speed - was Re: Modem


Re: TI-H: Linking Speed - was Re: Modem

On Sat, 31 May 1997 21:24:52 +0000, you wrote:
>Sami Khawam wrote:
>> I'm the one who dsigned the PICLink (see my page). THe
>> current problem is the the computer is sending data to
>> fast( at 9600 bps); When the PIC is still sending a byte
>> to the calc, the computer starts sending the next byte.
>> I wanted to know the fastest speed the calc can handel,
>> I used my computer to mesure it ( a parallel link, the
>> calc was runnig TALK), and I found that it was something
>> like 2500 bps! I don't know where is the problem, maybe
>> at the program that is runnig on the calc, TALK, (with
>> ZTerm it was even slower), or maybe at my calc?
>I'd guess it's the program, because the speed of the link port largely
>depends on how fast the software can handle it. ZShell routines like
>CALL_ and JUMP_ spend much processor time, so they should be avoided in
>time-critical routines like those that handle the link port. At some
>stage, the link port hardware refuses to work on very high speeds, but
>(according to Mel Tsai) you should still get much faster transfer speeds
>than your 2500 bps. I think the maximum was over 30kbps...

Right...  in my expander driver software I must place NOP instructions
between IN 7, * and OUT 7,* instructions otherwise it'll overrun the
link port.  But, the TI protocol is very inefficient so you'll be very
lucky to get 9600 bps.  But with complete software control it's around

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