Re: LZ: TI storage...
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Re: LZ: TI storage...
When it came to Re: LZ: TI storage..., Tony Lieuallen thought:
> marco@magenta.com wrote:
> > I don't quite remeber this being discussed, but what's wrong with
> > using conventional volatile RAM? Would it be all that hard to use
> > a 10 buck stick of 30-pin dram (1-2 megs) with a backup battery?
> > If someone could work it out economically, it would be a great
> > system (small, inexpensive, fast, and widely available).
> > Incorporate it with a backup battery (such as the lithium found in
> > the calc) as well as the main 9v, it would be great.
> >
> > Of course, someone tell me if I'm full of crap too. :)
>
> Yes, it would be that hard. There is A LOT of circuitry required to
> access a simm, and it's a lot more complicated than simply hooking
> up a battery to keep the data alive. Believe me. It would kill the
> battery pretty quick, anyway.
Yeah, a simm would be basically impossible to utilize, at least a
standard DRAM one. DRAM must be refreshed very frequently (not sure
of the number, but many times per second). SRAM would be possible
(not available as a simm AFAIK, but thats fine), but it would still
be a pretty big drain on the battery, especially a large amount of
it. And if you ever looked at Mel's first version of the expander
schematics, they were pretty complicated. You'd need somthing like
that to access a regular memory chip of any type. But Flash ROM and
EEPROM are available in a serial-access format, making them
semi-usable with the linkport. Thats how Mel was able to make the
Expander SF circuitry so simple.
Ben Shakal
shakalb98@jhs.net
shakal@ns.net
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