#robotics Logs

Feb 23 2012

00:00 rue_house if I put one more header on here, a 2x3, I can power the avr board off it too
00:00 rue_house which means all the power connections are on lugs, which would be nice
00:01 rue_house it would seal it to be not much smaller than it is now tho
00:02 katsmeow-afk what if you used a small dip header for pwr?
00:02 rue_house the distribution is via 18 guage wire
00:02 rue_house I'd like to keep it to lugs
00:02 katsmeow-afk so use 2 #20 instead
00:02 katsmeow-afk k
00:03 rue_house hmm 20A should be larger than 18 guage....
00:03 rue_house *blink*
00:03 rue_house funny, some things I find I design so well
00:03 tsmeow-afk considered a memory card for the commodore 64, but it needed 5v @ 750
00:04 rue_house I was once thinking about banked ram for a z80 that would be the size of a car
00:04 rue_house I didn't think about the power it would take
00:05 katsmeow-afk a 3ft long spindle to stack up cassettes on for saving files to in 1983 ,, naturally it would have twisted off
00:05 rue_house I'm using toms baords, they only have 1x3 headers, of which the gnd and 5V are all thats used
00:06 rue_house you alternate the spindle winding directions, so they tighten their neighbour
00:06 katsmeow-afk oddly, cassette tape is made by slitting a 10" wide tape, so a circle cut from the 10" wide and glued to a platter, i'd have had a homemade harddrive in 1983
00:06 rue_house hehe
00:06 rue_house my tape drive did 160cps iirc
00:07 katsmeow-afk i remember when a harddrive for a C64 cost $1000/megabyte
00:07 rue_house 4x40x2
00:07 rue_house so 320cps I suppose
00:08 rue_house I was excited
00:08 rue_house esp cause it was working with no errors
00:08 rue_house I wonder if I still ahve the tape with the test count on it
00:09 katsmeow-afk i remember uploading code to the floppy drive so i could use the computer for something else, because the floppy had Integrated Drive Electronics (ide)
00:10 rue_house I never used the tape drive port on an apple IIe
00:10 katsmeow-afk me either, or any porton a pdp11
00:11 katsmeow-afk i never used the LAN ports on a Cray-XMP
00:13 katsmeow-afk <cough>
00:13 rue_house I could make this baord tiny if I point to point wired it
00:13 e_house dosn't know the cray
00:13 rue_house does it have a water based cooling tower?
00:14 e_house waits for
00:16 e_house ->
00:16 katsmeow-afk umm, i don't remember
00:17 katsmeow-afk the early Crays came with their own cooling system
00:17 katsmeow-afk a freezer of sorts
00:18 katsmeow-afk http://www.google.com/search?q=cray-xmp&hl=en&rls=com.microsoft:en-us&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=8ddFT4-WAYrW0QG_wbHqAw&ved=0CC8QsAQ&biw=1068&bih=512
00:18 katsmeow-afk http://en.wikipedia.org/wiki/Cray_X-MP
00:19 katsmeow-afk The top-end system was the X-MP/48, which contained four CPUs for a theoretical peak system performance of over 800 MFLOPS and 8 million words of memory.
00:20 katsmeow-afk today, your phone may be faster and have more memory
00:21 katsmeow-afk The DD-39 and DD-49 hard drives made by Ibis with a raw transfer rate of 13.3 MB/s each stored 1.2 GB (blocked and formatted) with 5.9 MB/s and 9.8 MB/s transfer rates
00:21 katsmeow-afk my camera is faster than that, and with more memory
00:22 katsmeow-afk A 1984 X-MP/48 cost about US$15 million plus the cost of disks. In 1985 Bell Labs purchased a Cray X-MP/24 for $10.5 million along with eight DD-49 1.2 GB drives for an additional $1 million.
00:24 katsmeow-afk newer Cray : http://en.wikipedia.org/wiki/Cray_XK6
00:25 katsmeow-afk Each of the Tesla processors is rated at 665 double-precision gigaflops giving 63.8 teraflops per cabinet. The XK6 is capable of scaling to 500,000 Opteron cores, giving up to 50 petaflops total hybrid peak performance.[2]
00:27 katsmeow-afk the X2090 sports a 665 gigaflop (double precision) GPU, 6 GB of GDDR5, and 178 GB/second of memory bandwidth.
00:34 katsmeow-afk Wherever the SKA will ultimately be located, it will occupy one square kilometer of land (thus its name) and is expected to generate in excess of one exabyte of raw data each day.
00:36 katsmeow-afk 1 exabyte/day means installing 1000 terabyte harddrives per day
00:47 katsmeow-afk and filling 42 of them every hour with the raw data
00:48 katsmeow-afk 700 gigabytes per minute
08:46 rue_house I bet the machine bell bought was obsolete before it was paid off
08:47 Tom_itx huh?
13:19 katsmeow-afk prolly was
14:46 katsmeow-afk can't imagine the power use for all those bipolar 2k memory chips either,, there;s memory on ebay now that pulls 0.6 watts per chip, so 300 of them would be 180 watts for 150megabytes
15:04 tsmeow-afk puts them all in parallel so sequential access is 0.04 nanosec, or 2.3 gigabyes
17:02 katsmeow-afk oops, .43ns
18:41 katsmeow-afk 0.040 ohm resistor good for 20amps continuous = 25ft of #12 copper wire
18:42 katsmeow-afk or 15.5ft of #14, but it's going to get hot at 20amps constant, so needs a fan
18:43 katsmeow-afk or 9.8ft of #16
18:45 katsmeow-afk or 2.7ft of iron/steel(?) electric fence wire #14
19:04 Tom_itx latter definitely cheaper
19:14 Tom_itx rue_house, what ver debian are you running?
19:15 Tom_itx i'm grabbing a 6.0.4 iso for a new install..
21:01 katsmeow-afk Tom, yeas, it's only 20 turns on a 1/2" form <blink>
21:02 katsmeow-afk but at 0.8v drop at 20amps, gives good current sharing among the triacs
22:14 katsmeow-afk .
22:27 katsmeow-afk "And then, if they turn upon their ear to take a second nap, they will be taught to look upon it as an intemperance not at all redounding to their credit."
22:32 theBear pfft, my ear is very redounding to my credit
22:32 katsmeow-afk it should be, you do audio works!
22:33 theBear :)
22:38 tsmeow-afk skewers some marshmellows and puts em on the ba
22:38 katsmeow-afk woops! bad idea!
22:39 tsmeow-afk submits a $12.3 million grant proposal to congress to study the ef