On 9/10/25 23:12, William Morder via
tde-users wrote:
On Wednesday 10 September 2025 18:47:24 dep via tde-users wrote:
A long day and night with Commodore OS, in case anyone's interested.
https://ofb.biz/safari/article/1350.html
dep
Pictures: http://www.ipernity.com/doc/depscribe/album
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Commodore Amiga 64 was my very first desktop computer. My son tried to break
it by playing games like "Defender of the Crown", using the keyboard and
mouse were actual lances and swords.
It occurs to me that, if data can be deliverered via shortwave, why not
internet? Also why not internet over the radio / televison spectrum?
I do have a shortwave radio receiver, though I don't use it much. I wonder if
I could hack it to receive data over shortwave, then somehow transfer it to
my laptop? I do have a patch cord, but that's just for sound ... I think.
Maybe somebody else out there who knows more about these things (thinking of
you, Gene!) might be able to tell me why this cannot possibly work.
Bill
Yes it /could/ work, Bill, but introducing the noisy world of broadcast does entail an attention to detail involving frequency accuracy and some sort of an error correcting algorithm where sufficient redundancy exits in the code format to make self correcting code practical. Fire coding comes to mind, but even that requires sufficient redundancy to fix multi bit errors created by a leaky crossbar on a power pole. A pole originally equipt with 2400 volt rated glass insulators, up-graded to carry 7200 volts w/o replacing the insulators, compounded by the diagonal steel braces holding the crossbar level but with the center bolt into the pole not having been re torqued since it was originally bolted up in 2400 volt REA days. There does not exist in this scenario, a method to demand a re-transmission of corrupted data. All the common methods today, rzsz, tcp, probably a dozen other's, all work because its a 2 way path. Corruption detection is easily done with a crc on each sectors (256/512) worth of data, but w/o the on demand retransmission, is hellishly difficult. Yes, that case IS 2 way. But the speed of light time delay doesn't make it easily done.
Our voyager satellites are delivering only femtowatts of signal at goldstone, so I expect half of the available bandwidth is devoted to error detection & correction. At that power level, I'd be amazed if they are functioning at over 1 bit per second. Their plutonium thermally generated power is nearing the end, and it will take electronic magic to get data from them in another decade. And one hell of a budget item for boiling helium to maintain the half degree kelvin the electronics at the focal point of the goldstone dishes need to be able to hear the voyagers in the face of that half degree of thermal noise. It's all we got in this case.
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Cheers, Gene Heskett, CET.
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