Subject:
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Re: Mindstorms NXT programming languages
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Newsgroups:
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lugnet.robotics
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Date:
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Fri, 13 Jan 2006 20:34:34 GMT
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Original-From:
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dan miller <danbmil99@yahoo.+NoMoreSpam+com>
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Viewed:
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2389 times
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good analysis. Also keep in mind that Lego sells primarily through retail
resellers, so their take is considerably less than the SRP. (Even the Lego
stores have huge overhead, being in expensive malls).
To sell a product like this at < $250 and make a profit, every dollar
counts.
What this discussion really points out IMSHO, is that there is _some_ part
of the community that would pay more for more performance. Hopefully,
that's what the ports are about. I can see someone adding CF flash reader
to a port, for instance. It could even be through bluetooth.
If the platform is truly open and extensible, these discussions will be
moot.
--- Mike Walters <mgwalters@[stopspam]>,
UNEXPECTED_DATA_AFTER_ADDRESS@.SYNTAX-ERROR. wrote:
> In lugnet.robotics, John Barnes wrote:
> > Is there an apples and oranges problem here? You are referring to serial • memory
> > devices used for data storage versus broad side FLASH which permits the • CPU to
> > execute from it.
> >
> > If the CPU were to be crippled by executing from a SD memory device, I • think
> > you'd start complaining about the speed at that point.
> >
> > So how much does 32 bits wide of 64Mb of FLASH cost?
>
>
> I think, John, you've finally started us down the right path to
> (hopefully) put
> this whole topic to bed.
>
> What we're talking about here isn't necessarily a difference between
> serial
> FLASH and parallel FLASH. What we're talking about is the difference
> between
> NAND FLASH and NOR FLASH.
>
> The type of FLASH that is used in CF cards nowadays is NAND FLASH. CF
> uses an
> 8-bit parallel interface. NAND FLASH requires a file system for access
> and is
> NOT randomly accessible. It is suited for mass storage (such as a CF
> card).
> Products that use NAND FLASH for program storage download the program into
> DRAM
> prior to execution. They do not (can not) run the program from NAND
> FLASH.
>
> The type of FLASH this is used to run firmware from directly is NOR FLASH.
>
> Although a company like Lego (or any company larger than a garage) would
> never
> buy from Digikey, we can use Digikey as a readily available comparison
> source:
>
> A 128Mbyte CF card (as was used for comparison earlier in the thread)
> contains
> some combination of NAND FLASH chips that add up to 128M x 8. If you look
> at
> Digikey, you will find that you can do this for about $20 in small
> quantities.
> Given Lego's volumes, their cost will certainly be much less than that,
> but more
> than the high-volume CF card makers can do with their high volumes. Let's
> say
> that it would cost Lego $10 to put 128Mbyte of CF in the NXT. If they
> didn't
> want to make a profit and it didn't cost anything in PCB space or
> engineering,
> they could theoretically do this and only add $10 to the cost of the
> product.
> Of course, it'd be NAND FLASH and would only be useful as a mass storage
> device,
> not code storage.
>
> On the other hand, to add "1000 times" the amount of CODE memory to the
> NXT,
> we'd need 256Mbytes of NOR FLASH (the NXT has 256Kbytes as is). 256Mbytes
> is
> 2Gbits. Let's say that we wanted it x32. In that case, we'd be looking
> for
> some combination of NOR FLASH chips to give us 64M x 32. The problem is
> that
> NOR FLASH isn't available in as high of densities as NAND FLASH. To build
> our
> 2Mbits of memory, we're looking at possibly 8 256Mbit parts. At $27 each.
> Applying our economies of scale, we're talking about over $100 dollars to
> give
> the nxt "1000 times" the amount of FLASH memory. Even assuming that we
> could
> divide that cost by 2 again, given time to find the righ suppliers, we're
> still
> talking about over $50 additional cost, without even looking at the
> addition PCB
> space and engineering time.
>
> Then again, I guess that's a long drawn-out process to go through when we
> could
> have just realized that Lego has already done this.
>
> Thanks for pointing this in the right direction, John. It was kind of
> interesting to finally go through the actual thought process.
>
> Mike
>
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Message is in Reply To:
 | | Re: Mindstorms NXT programming languages
|
| (...) I think, John, you've finally started us down the right path to (hopefully) put this whole topic to bed. What we're talking about here isn't necessarily a difference between serial FLASH and parallel FLASH. What we're talking about is the (...) (19 years ago, 13-Jan-06, to lugnet.robotics)
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