Re: TI-H: Internal mem expander question


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Re: TI-H: Internal mem expander question




Until you've made one one and have proof with pictures, don't say it works.
You can't just throw it in parallel and be happy...

Saying it won't is one thing, but you say it will.  How many TI owners do
you want yelling at you when they've burnt their fingers and calc pcb
trying to do this?  :)


>AHEM... Like I said... use the original circuitry, but have that switch that
>Grant was talking about. It WILL work if you have it in parallel, with the
>switch setup korrectly.
>
>
>On Fri, 20 Nov 1998 20:16:45 -0500, Jon Olson wrote:
>
>>
>> I don't think that's exactly what he means. See, when you turn the calc
>off,
>> it doesn't actually "turn off", because you would lose all the contents
>of
>> your memory. It is my understanding that when it's "turned off" the chip
>is
>> in a sleep state, and the memory is still active. Therefore, this
>switching
>> could cause some serious problems. Just a thought...
>>
>> -- Jon Olson
>>
>> -----Original Message-----
>> From: Firepower5@aol.com <Firepower5@aol.com>
>> To: ti-hardware@lists.ticalc.org <ti-hardware@lists.ticalc.org>
>> Date: Friday, November 20, 1998 7:01 PM
>> Subject: Re: TI-H: Internal mem expander question
>>
>>
>> >
>> >In a message dated 11/20/98 5:52:13 PM Central Standard Time,
>> >gussie@alaska.net writes:
>> >
>> >> >>  Get it?  :) having it work 50% of the time isn't fun...
>> >>  >I don't quite understand this.  Have you looked at the plans, Grant?
>> To
>> >me
>> >>  >(and I don't think I know as much as you at all, but...) they make
>> sense,
>> >> and
>> >>  >it's very hard for electronics to make sense to me.  Maybe I'm
>wrong,
>> >but...
>> >>
>> >>  >what would make this work 50% of the time?  It is possible it would
>not
>> >> work
>> >>  >at all, or work all the time, but 50%?  That just doesn't make sense
>to
>> >me.
>> >>  >Keep in mind I am not flaming you, I am asking a question.
>> >>  Switching CS lines improperly.  There is a setup/down time that is
>about
>> >>  200ms I think.  If you leave it at high impeedance it can leave the
>chip
>> in
>> >>  unexpect states.
>> >So you mean that after turning the calc off, you have to wait 200 ms
>before
>> >switching the switch, and another 200 ms before turning it back on?
>> >
>> >Rob Hornick
>> >
>>
>
>
>
>
>
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