On Sat, Feb 1, 2025 at 10:54 PM Fred Cisin via cctalk <cctalk@classiccmp.org> wrote:
> > IBM used a DB25 socket for their printer port at the computer end, > (male on the card for serial, female on the card for parallel "Centronics") > THAT, of course caused some idiots to attempt to use the parallel port for > serial and vice versa. "I just need a 'gender changer'!" :-) The worst screw-up there (IMHO) came from HP in the HP150 series. This machine had 2 RS232 serial ports as standard on DB25 sockets, wired for some inexplicable reason as DTEs. There was an add-on board that included a parallel printer port. To avoid confusion, this was a DB25 plug. But the board had been laid out for a DB25 socket using the IBM PC pinout. The result was that stb/ ended up on pin 13, D0 on pin 12, and so on. -tony
