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drmpeg

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Tenstorrent QuietBox Tested

theregister.com
4 points·by drmpeg·8 ay önce·0 comments

Analysis of Hedy Lamarr's Contribution to Spread-Spectrum Communication

researchers.one
66 points·by drmpeg·8 ay önce·54 comments

ATSC 3.0 Further Notice of Proposed Rulemaking [pdf]

docs.fcc.gov
1 points·by drmpeg·9 ay önce·0 comments

comments

drmpeg
·18 gün önce·discuss
I was the project engineer for the Air Force Space Command / NORAD DSP satellite ground network back in the 80's. The system used the 10MB 8" Bernoulli drive and cartridges to store the early warning message traffic. The system was installed in 1988 and was decommissioned around 2005.

I'm not sure if they used the 8" cartridges all the way to 2005, but I can find out. I'm still friends with the original system maintainer. I pivoted to video compression in 1993 and lost track of the program, but we found each other on Facebook in 2010.
drmpeg
·25 gün önce·discuss
Advanced Television Systems Committee. It's the US standards organization for terrestrial digital television. ATSC 3.0 is a new standard that's very similar to DVB-T2 (used in the UK for HDTV) at the PHY layer.
drmpeg
·25 gün önce·discuss
Little known Fabrice Bellard project. He worked with the ATSC to test the ATSC 3.0 PHY layer when he was consulting at DekTec.
drmpeg
·2 ay önce·discuss
The article kind of disses the Intel 8085. For those of us with 8080 code bases that were never going to be rewritten for the Z80, it was a welcome upgrade. On the paper dryer process control systems I was working on in 1979, the 8085 based Intel 80/30 Multibus SBC could be dropped in for the older 8080 based 80/20 SBC with no changes and provide a significant 2.5X performance upgrade.
drmpeg
·2 ay önce·discuss
Looks like the esp4 and esp6 fixes have been pushed for 7.0, 6.18, 6.12 and 6.6 kernels.

https://lore.kernel.org/lkml/2026050851-iron-hurdle-6421@gre...

https://lore.kernel.org/lkml/2026050843-unplowed-spinster-cf...

https://lore.kernel.org/lkml/2026050832-remold-faceless-bed0...

https://lore.kernel.org/lkml/2026050825-heaving-spender-13a8...
drmpeg
·3 ay önce·discuss
Previous post.

https://news.ycombinator.com/item?id=45790672
drmpeg
·4 ay önce·discuss
It's actively being maintained by Takashi Sakamoto. Here's the commit for Linux 7.0-rc1.

https://github.com/torvalds/linux/commit/0d6dd4738dbcc32b60c...
drmpeg
·4 ay önce·discuss
Meyer lemons from my backyard.

https://www.w6rz.net/lemons.png
drmpeg
·5 ay önce·discuss
Here's an emulation of WWV I did with a transmit capable SDR.

https://www.youtube.com/watch?v=9LsJn0CyyZI
drmpeg
·6 ay önce·discuss
VSB came later. From https://www.tvtechnology.com/opinions/hdtv-from-1925-to-1994

In the United States in 1935, the Radio Corporation of America demonstrated a 343-line television system. In 1936, two committees of the Radio Manufacturers Association (RMA), which is now known as the Consumer Electronics Association, proposed that U.S. television channels be standardized at a bandwidth of 6 MHz, and recommended a 441-line, interlaced, 30 frame-per-second television system. The RF modulation system proposed in this recommendation used double-sideband, amplitude-modulated transmission, limiting the video bandwidth it was capable of carrying to 2.5 MHz. In 1938, this RMA proposal was amended to employ vestigial-sideband (VSB) transmission instead of double sideband. In the vestigial-sideband approach, only the upper sidebands-those above the carrier frequency-plus a small segment or vestige of the lower sidebands, are transmitted. VSB raised the transmitted video bandwidth capability to 4.2 MHz. Subsequently, in 1941, the first National Television Systems Committee adopted the vestigial sideband system using a total line rate of 525 lines that is used in the United States today.
drmpeg
·6 ay önce·discuss
Although everyone is interested in visible aurora, the proton flux is also really impressive. It peaked at 37,000 pfu at 1910Z. The highest ever recorded was 43,500 pfu in March 1991.
drmpeg
·6 ay önce·discuss
VistaVision has made a comeback with "The Brutalist", "One Battle After Another" and "Bugonia".

https://en.wikipedia.org/wiki/VistaVision
drmpeg
·6 ay önce·discuss
Here's some captures from my Comcast system here in Silicon Valley.

https://www.w6rz.net/528x480.ts

https://www.w6rz.net/528x480sp.ts
drmpeg
·6 ay önce·discuss
> Videos with non-square pixels are pretty rare...

Before HD, almost all video was non-square pixels. DVD is 720x480. SD channels on cable TV systems are 528x480.
drmpeg
·7 ay önce·discuss
There's some thought that Ukraine could become a tech hub after the war due to their drone technology.
drmpeg
·7 ay önce·discuss
Here's my ATSC 3.0 transmitter in C++.

https://github.com/drmpeg/gr-atsc3
drmpeg
·7 ay önce·discuss
Here's the Emmy that C-Cube Microsystems won back in 1995 for the MPEG-2 (actually unconstrained MPEG-1) encoder chip set used in the roll-out of DirecTV.

https://www.w6rz.net/DCP_1235.JPG

The original DirecTV encoder was MPEG-1 at 704x480 using eight CL4000 chips. Then in 1995 when the MPEG-2 capable CL4010 was finished, the encoders were upgraded to MPEG-2 (frame only encoding). Then upgraded again to a 12 chip AFF (Adaptive Field/Frame) encoder when the firmware was completed.

https://www.w6rz.net/videorisc.png
drmpeg
·7 ay önce·discuss
I believe he's using a 6m antenna at the Allen Telescope Array (ATA).
drmpeg
·7 ay önce·discuss
The first 16:9 content I ever saw was the trailer to "Batman Forever" (with Val Kilmer) in 1995 when I was working at C-Cube Microsystems. The studios use to send them test content all the time for video compression testing. It was on D1 tape, and looked beautiful for SD resolution. The professional Sony CRT 4:3 monitors back then had a 16:9 button to letterbox the image.
drmpeg
·8 ay önce·discuss
Yes, you have it correct.

However, predicting the effects of solar flares is very difficult. Not only does the particle stream have to hit the Earth, it has to couple with the magnetic field.

Large flares can cause small events on Earth and vice versa.