30-April-2002, 01:32 AM
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Senior Member
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Join Date: Oct 2001
Location: USA
Posts: 309
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Quote:
On 2002-04-29 18:53, JayUtah wrote:
Wow, you read my mind. I was just going to comment on the NTSC video signal standard using an analog phase modulation.
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Here's an interesting historical tidbit, NASA standard telemetry has the bytes aligned with MSB first, vs. industry standard LSB first. Why? because the first digital data systems were essentially just a successive approximation A/D converter hooked directly to the encoder. A SA A/D converts the most significant bit first, successively deciding which bit is a "1" or a "0". Before integrated circuits, storage registers had to be built with discrete transistors, so storing the bits to reverse the order for transmission would take a lot of hardware, so instead, each bit was jammed into the downlink as it was converted. |