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The thing I don't get about this is why did people think it was a good idea to have a serial connection over DB-25? You honestly need only 3 wires. Not 25

For a Parallel port, sure 25 wires is right there. But not for a serial port



CTS, DCD, DSR, DTR, GND, PG, RI, RTR, RTS, RxD, TxD (alphabetically) makes around 11, I think.


Plus the differential versions of most of those signals for long distance doubles the number of pins. And they have optional synchronous clocks. I did some WAN work for 3Com back in the day... :)


A few devices back in the day could be powered over DB-25 connections besides the communications, even. Some in factories might still be.


If I recall correctly, the DB-25 RS-232 cables also facilitated two serial connections.


You do. (I've never seen that used, though.)


Yes and then we came up with soft flow control for the win




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