Interfacting with RAM? (Say, 32kbyte or more)
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Anyone know of some good way to interface with real amounts of RAM?
They've got 512kbit EEPROMs out there. They've got little tiny serial
RAM chips. Am I overlooking something or some way of interfacing a
basic stamp to some real amout of RAM?
They've got 512kbit EEPROMs out there. They've got little tiny serial
RAM chips. Am I overlooking something or some way of interfacing a
basic stamp to some real amout of RAM?
Comments
jmccorm@y... writes:
> Anyone know of some good way to interface with real amounts of RAM?
> They've got 512kbit EEPROMs out there. They've got little tiny serial
> RAM chips. Am I overlooking something or some way of interfacing a
> basic stamp to some real amout of RAM?
>
We have a device that will store 500 entries, upto 128 bytes per entry in
real time. Please concact me off-line.
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
1. These EEPROMS can 'only' be written something
like 1,000,000 times. This is fine if you don't want
to scan video or something.
2. These EEPROMS are serially interfaced.
Some use I2C -- which means only certain BS2 platforms
support them. Some lesser ones (64 KBytes) use
SPI, and should work fine.
3. It does take some time to access (write) these
EEPROMS -- on the order of milliseconds. Thus, again
you can't use them for video. Since the BS2 has like
52 Bytes of RAM, having 64 K of 'slow' RAM hanging off
them is helpful, but can be limiting, also.
Other than that, they should be fine. Non-volitile,
write often, very good for logging purposes. But
you can't treat them like 'local' RAM.
--- In basicstamps@yahoogroups.com, "jmccorm" <jmccorm@y...> wrote:
> Anyone know of some good way to interface with real amounts of RAM?
> They've got 512kbit EEPROMs out there. They've got little tiny
serial
> RAM chips. Am I overlooking something or some way of interfacing a
> basic stamp to some real amout of RAM?
>They've got 512kbit EEPROMs out there. They've got little tiny serial
>RAM chips. Am I overlooking something or some way of interfacing a
>basic stamp to some real amout of RAM?
http://www.solutions-cubed.com/solutions%20cubed/RPB2003.htm
> Anyone know of some good way to interface with real amounts of RAM?
I have used a 128x8 static RAM chip on a project that needed some
extra RAM. A few latches, shift registers and some logic is all that
it took. I had other parallel devices that I needed to interface as
well so much of the circuitry was common. You can find links to
schematics for the interface and code at
http://www.kinzers.com/don/GenSet.
For another project I was considering using a 32Kx8 Hitachi static
RAM - HM62256 using the same type of interface. You can get data on
that device here:
http://www.web-ee.com/Electronic-Projects/data/hm62256.pdf
For even more memory, check out the HM628128 - 128Kx8.
Here is a cross-reference of RAM devices that may be useful:
http://www.flippers.com/StaticRam.html
> Anyone know of some good way to interface with real amounts of RAM?
> They've got 512kbit EEPROMs out there. They've got little tiny
serial
> RAM chips. Am I overlooking something or some way of interfacing a
> basic stamp to some real amout of RAM?
I'm interested in what you mean by real ammount of RAM.
We are in a pre-release stage of a couple products, one has a small
amount of ram that is non-volitle, but it is only in the 20-30k
neighborhood.
Another we have is an EPROM device that goes into lots more memory,
but it is not RAM.
Can you offer an idea what the typical use might be ?
Dave
> > basic stamp to some real amout of RAM?
>
> I'm interested in what you mean by real ammount of RAM.
Most of the RAM chips I've seen out there for the basic stamp are
pretty wimpy. We're talking a neighborhood of 2kbit or less being
common in serial RAM. I'm pretty much satisfied with 512kbit EEPROMs
on an I2C bus.
> We are in a pre-release stage of a couple products, one has a small
> amount of ram that is non-volitle, but it is only in the 20-30k
> neighborhood.
That's certainly a step above what is common out there.
> Can you offer an idea what the typical use might be ?
That's a fair and good question. What's the killer app for RAM?
Guessing I'd say imaging/video/display/digitization. Of course, if you
put more RAM out there, it'd be great to provide the killer app with
it. [noparse]:)[/noparse]
> Anyone know of some good way to interface with real amounts of RAM?
> They've got 512kbit EEPROMs out there. They've got little tiny serial
> RAM chips. Am I overlooking something or some way of interfacing a
> basic stamp to some real amout of RAM?
If you need more RAM, maybe you should investigate some of the other
8-bit processors on the marked. Zilog's eZ80Acclaim supports up to 256
KB of Flash RAM, 16 KB of SRAM and 16 MB of external RAM. More
informatioin here
http://barrymichels.com/ide/
It is an interface to a CF card or IDE hard drive, but it also
includes 128kbytes RAM and an LCD. He started the prototyping using
a Stamp, with discussion here on this list, and then moved the
control over to a PIC16C877. It has a serial interface (to the Stamp
or a terminal).
-- Tracy
> > > Am I overlooking something or some way of interfacing a
> > > basic stamp to some real amout of RAM?
> > > Am I overlooking something or some way of interfacing a
> > > basic stamp to some real amout of RAM?
> >
> > I'm interested in what you mean by real ammount of RAM.
>
> Most of the RAM chips I've seen out there for the basic stamp are
> pretty wimpy. We're talking a neighborhood of 2kbit or less being
> common in serial RAM. I'm pretty much satisfied with 512kbit EEPROMs
> on an I2C bus.
The problem with EEproms is the limited read/write cycles. Our RAM
board will offer in the trillions or read/write.
>
> That's certainly a step above what is common out there.
>
> > Can you offer an idea what the typical use might be ?
>
> That's a fair and good question. What's the killer app for RAM?
> Guessing I'd say imaging/video/display/digitization. Of course, if
you
> put more RAM out there, it'd be great to provide the killer app with
> it. [noparse]:)[/noparse]
There in lies the problem. We can offer the 64k or 256k ram, but
whatch-ya gonna do with it ?
Our need was as a temporary storage before sending a page to the data
logger. The 512k data logger can only accept page write so there is
a little limit on the value, unless you can fill up a whole page.
Enter the need for RAM, at least for us.
But, look for neat things in the near future !
Since we are using the BS2 there are some some features that might be
gained by going to one of the faster Stamps. Gotta love the Stamp !
Dave