fcc opened up 6ghz band for nextgen wifi devices

We’ve gotten utilized to the truth that the clocks on our internet-connected computers as well as smartphones are always telling the ideal time. Time servers, supplied by a range of government companies in addition to tech giants, supply them with the precise time as well as date thanks to precise atomic clocks as well as the creative Network Time Protocol (NTP). however it wasn’t always like this: back in the 1990s when lots of computers didn’t have an Web connection, we had to change our computers’ clocks manually. go back one a lot more decade, as well as lots of PCs didn’t even have a battery-backed clock at all; you either set the appropriate date as well as time when the computer booted, or just dealt with the truth that all new data were timestamped 01-01-1980.

[Michael Brutman] made a decision to mix today’s world of network time synchronization with the old world of batteryless PCs, as well as developed an SNTP Time Server that runs on a DOS PC. He tried it with two different hardware setups: a 40 MHz 386 PC from 1993, as well as the (in)famous IBM PCjr from 1984. A common GPS module serves as an precise time reference; these units can commonly be directly linked to old hardware thanks to the eternal RS-232 standard.

Simply having an precise clock was not sufficient though: the original IBM hardware had its interior clock only updated every 55 milliseconds, which is not quick sufficient for a appropriate NTP server. [Michael] as a result had to modify the hardware clock’s update rate, taking care not to overload the CPU with as well lots of interrupts. The sluggish CPU as well as restricted memory anyway needed him to carry out the basic Network Time Protocol (SNTP), a stripped-down version of the a lot more typical NTP, which leaves out a few of the a lot more complex features that offer with synchronizing several servers. The network interface is handled by [Michael]’s own mTCP package, which is a TCP/IP stack created for DOS machines with restricted memory.

Tests comparing the DOS time server to the one run by Google showed an balance out of no a lot more than a few milliseconds, which must be just fine for keeping all PCs on your house network in sync. Although utilizing an old PC is not the most functional method to run your own time server, [Michael]’s blog publish is a interesting deep dive into the finer points of PC clock design as well as network time synchronization approaches. We’ve seen a time server implemented on ESP8266 hardware before; however you might likewise dispense with the (S)NTP protocol completely as well as directly link a GPS module to your Raspberry Pi for precise timing.