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Old 1st January 2013, 05:47 PM   #2471
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After I verify functionality I will gladly post the files. Anyone can then change packages if need be and order some.
More amazing is that the original CRAY-1 is bested by a cheap laptop.
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Old 1st January 2013, 05:58 PM   #2472
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For those that missed the reference to "Dilbert". Dilbert is a long run newspaper comic series about a design engineering office gone bad.

The official Dilbert website with Scott Adams' color comic strips, animation, mashups and more!
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Old 1st January 2013, 06:39 PM   #2473
bcarso is offline bcarso  United States
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Default Teeny packages, somewhat off-topic

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I stuck with TO-92 outputs and J310 cascodes for now and found some SOT23-6 duals NPN/PNP, PNP/PNP, and NPN/NPN I'm not ready for those tiny packages yet.
Working today (paying work, nice way to start the new year even if it isn't audio) trying to find the best way to open-circuit the I2C I/O of a part in a watch, so it can be powered down to save battery life but share the bus with an EEPROM. There are many analog switches out there now for low voltage operation, but the smallest packages I've found with the appropriate low capacitance are huge: SOT23-6 There are smaller ones but they are 0.5 ohm on resistance and correspondingly high capacitance.

So I turn to discretes. Rohm makes dual MOS parts in their VMT6 package, about 1.2mm x 1.2mm . With two packages per line, N and P, each dual connected back-to-back, and complementary drive signals, in essence rolling one's own dual bilateral switch, it can be done, and with acceptably low capacitance. The SOT23-6 parts that are SPDT are singles, hence two needed for the two lines. To remind, SOT23 has about a 3mm x 3mm footprint.

One could at this point ask if there couldn't just be another port on the uC and a separate I2C interface thus. The answer is, maybe, if other line functions might be consolidated.
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Old 1st January 2013, 06:58 PM   #2474
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bcarso,
What type of watch are you working on that would have short battery life these days? Can't fathom that. I still have the original Acutron red faced led watch I had as a kid, that had some sort of micro-switch that all you did was move your wrist quickly and it would light up the display. Learned my first mechanical lessons fixing pocket watches as a kid.
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Old 1st January 2013, 07:20 PM   #2475
bcarso is offline bcarso  United States
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bcarso,
What type of watch are you working on that would have short battery life these days? Can't fathom that. I still have the original Acutron red faced led watch I had as a kid, that had some sort of micro-switch that all you did was move your wrist quickly and it would light up the display. Learned my first mechanical lessons fixing pocket watches as a kid.
It's a watch with many functions accessible with a touchscreen. The standby current equates to a long battery life, but if you start using some of the functions, particularly the LED backlight, or stopwatch, or... things deteriorate significantly. I have been hovering around the project without being involved from the outset, just called in when the client is desperate. Involvement at the beginning might have made a lot more sense, but you know how these things go.
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Old 1st January 2013, 08:14 PM   #2476
PHEONIX is offline PHEONIX  Australia
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Quote:
Originally Posted by scott wurcer View Post
Finished my boards, separate input and output stages that fold into a 1"x1" stack. I stuck with TO-92 outputs and J310 cascodes for now and found some SOT23-6 duals NPN/PNP, PNP/PNP, and NPN/NPN I'm not ready for those tiny packages yet.

Filled in with some SOT23 to DIP-6 adaptors for matched pairs.
Hello Scott

What PCB board layout software do you use.
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Old 1st January 2013, 09:40 PM   #2477
qusp is offline qusp  Australia
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probably altium
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Old 1st January 2013, 09:56 PM   #2478
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Quote:
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More amazing is that the original CRAY-1 is bested by a cheap laptop.
So the foke-lore on the street says. But, the laptop cpu architecture isnt optimized for number crunching and the word size is a lot smaller etc etc. Larger word size means more can be done in each cycle. Number crunching is what the super's do best as they have a lot of it to do. Also, the use of memory is much faster and a lot more of it. etc etc etc. [ I was at LLNL when the first Cray went in and subsequent ones etc.] Thx-RNM

Last edited by RNMarsh; 1st January 2013 at 10:19 PM.
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Old 1st January 2013, 10:20 PM   #2479
bcarso is offline bcarso  United States
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Windoze 7 does support 64 bits now, same (approximately) as the Cray-1.
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Old 1st January 2013, 10:30 PM   #2480
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Hello Scott

What PCB board layout software do you use.
Stuck with ExpressPCB all free but you can't transfer the results to another CAD package.
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