Re: TI-H: TI Modem


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Re: TI-H: TI Modem




TI-92?
::waves hands::
Uh, guys?  I have an 86.
::silence::

>From: Calan <clambert@geneva.edu>
>Reply-To: ti-hardware@lists.ticalc.org
>To: ti-hardware@lists.ticalc.org
>Subject: Re: TI-H: TI Modem
>Date: Sun, 23 May 1999 16:55:38 -0400
>
>
> > Grant Stockly wrote:
> >
> > >Instead of having to access the link port (at 36 kilobits baud or 
>whatever it
> > >is) a chip can be hooked up directly to the CPU of the TI92 (through 
>the ROM
> > >expansion module) and be accessed at about a megabyte a second (I 
>BELIEVE, may
> > >not be quite that fast.  It also depends on the software used to read 
>the
> > >data.)
> >
> > You can get it to 5k a second through the link port.
> >
> > The 68000 at that speed can do ~8MB a second.
> >
> > >on a normally clocked TI92.  This would require only the chip that you
> > >need to access with no serial interface.  It's cheaper (you don't need 
>a
> > >serial
> > >interface), simpler (you don't need program in all the serial stuff, 
>you just
> > >copy a memory location) and a whole lot faster (already discussed).
> >
> > Sorry,
> > You're going to have to do more than just write to a memory location.
>
>I have no clue how the network chip works (although I am very interested).  
>But
>from what I can tell, you just read from the buffer, right?  Can you not 
>map the
>buffer as memory?
>
>Using a 10 MHz chip, that would give a 2.5 MHz bus speed.  The chip has to 
>read in
>the instruction which will take 1 to 2 bus cycles (not sure, didn't check), 
>then it
>has to copy the information taking another two bus cycles.  At 16-bit, that 
>is
>about a megabyte per second, using the most efficient code that I know of 
>(I'm not
>a programmer):  move.w (a0),(a1) over and over for the size of the buffer.  
>That is
>not 1MB per second access speed, but 1MB per second copy speed.  Just out 
>of
>curiosity, where do you get 8MB?
>
>That's a lot more than 5k per second either way  (Yes, 36 kilobits is about 
>5
>kilobytes per second.  4.5 actually.)
>
>I understand that every calc has a link port, but the way I see it any of 
>these
>fine people on TI-hardware who want to network their TI92 would most likely 
>be
>willing to do a modification or if they own a TI92 use the ROM slot.  Heck, 
>why not
>just put the chip IN the TI, and then add a network socket on the side or
>something?  This isn't a commercial product or anything, it doesn't need to 
>be
>adaptable to every TI in the world, just those who want it.
>
>--
>-Calan
>
>Chris Lambert
>clambert@ieee.org
>Member of Geneva College Student Branch IEEE
>Head of Marvin Robotic Development Team
>URL:  www.geocities.com/SiliconValley/Peaks/6869
>
>
>


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