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Cake day: May 29th, 2024

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  • Since the portable radio doesn’t have much power, you may need to use digital modes to get through.

    I don’t know much about radio stuff, but ever since I learned about LoRA I’ve wondered what kind of range a station could get if the longwave or AM bands were repurposed for use with a spread spectrum digital protocol. And what kind of bandwidth something like that would have.

    I think being able to do datacasting over really long ranges would be useful, so, for example, you could send emergency alerts to people even if the local cell infrastructure was down. But with the way things are headed I guess that role will be taken up by satellites.


  • The microcode in integrated CPUs took care of routing your inputs and outputs to where they need to be, and triggering the various arithmetic operations as desired.

    In the transition from plugboards to programmed sequence control the thing that took over the task of routing values between registers, through the ALU, and to/from IO ports was the control unit. Microcode being one way to implement functionality in the control unit.

    One other approach was to use what was basically a finite state machine, implemented physically in-circuit. The output of that FSM was fed into a series of logic gates along with the current instruction value, with the output of that combination being connected to the control lines of the various CPU elements. Thus the desired switching/routing behavior occured.

    Modern chips are really complicated hybrids of microcode and a ton of interacting finite state machines. Especially in x86 complex or less commonly used instructions will be implemented in microcode, whereas simple/common instructions will be implemented by being “hardwired”, somewhat similar to the FSM technique described above (although probably more complicated).