• rumba@lemmy.zip
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      15 hours ago

      Although serial and parallel shared the same overall pin count and connector style, they used opposite genders and the two were incompatible.

      Generally, If the port on the PC was male it was serial if the port was female it was parallel. But realistically you’d never see a 25-pin serial on a computer unless you were looking at something very ancient and strange. Even back into the '80s, The PCs used DB9 connectors for serial and adapters or the cable itself would have to convert it over the standard 25 pin connector on the modems.

      • barsoap@lemm.ee
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        10 hours ago

        they used opposite genders

        Not necessarily. For IBM PCs that was true, but my UltraSPARC had a differently-gendered serial port which was very annoying because neither standard straight nor null-modem cables worked. It was a DB-25, carrying two ports.

        Those connectors were used for a lot of different things, with no autonegotiation no nothing. At least the pinout for port A was compatible with the standard DB-25 one-port pinout, just with different gender.