Re: LZ: Re: RAM EXPANDER IMPORTANT ANNOUNCEMENT -- Please


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Re: LZ: Re: RAM EXPANDER IMPORTANT ANNOUNCEMENT -- Please



On Tue, 15 Oct 1996 21:23:10 -0600, you wrote:
>Alright!  I don't mind a delay as long as you make it worth while!=20
>Bi-directional parallel ports on newer cards supporting the 16550 serial
>chip are EPP ports right? =20


No, an EPP has nothing to do with 16550 serial ports.  EPP's are just
regular parallel ports that become bidirectional, as well as much
faster.  They won't be needed for the computer-expander link, but they
support higher transfer rates.


>Also, you could solder on a Serial Flash chip
>for the first meg then have another chip, for the second meg, a RS232 =
port
>(for modems and mice and whatnot!), a passthru port for another calc to
>access or for this calc to access another device such as the computer, =
all
>together or have a combo of those and other memory banks!  I suppose the
>method being used is sort of like parallel processing, and 50-60kb/s!=20
>That's like more than 2x faster than a 28.8!  Haha!  Think about a =
TI-Calc
>ISDN line! =20


Well, 50-60kb/s is the *theoretical* maximum.  Regular TI-85's won't
even get close to that rate (even with multiple-bank simultaneous
access), only the TI-92 (maybe) and the computer-expander link will
even get close to that limit. =20


Also, once you get past 2 "banks", the software also becomes
exponentially more complicated.  Unless people use the "standard"
organizations of what I'm designing, they'll have to write the
software themselves!  Also, if you want to use a simultaneous serial
port, special software will have to be written because it's not the
same as just accessing the link port.


BTW, 60kb/s is about 25 times faster than a 28.8 modem.


>Also, you did
>mention something about bringing data from the expander into internal
>memory to handle; can't you just leave it on the expander? =20


You still need parts of the OS left in RAM, otherwise there's no way
to access the expander.  The details of the software that does the
on-the-fly variable downloading are complicated, but they'll
eventually get done.  It's definitely at least a month or two in the
future.


-Mel


<pre>
--
The TI Memory Expansion Homepage
http://pilot.msu.edu/user/tsaimelv/expander.htm
</pre>


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