Hi folks. Hope all is well. Can some one please tell me why in the olden days, computers had connectors with 16,28, 20 pins? My printer, today, has only one USB cable going into the tower. ( 2 for power and 2 for data and life is good). But in the olden days they had like tons of pins.
What technical need necessitated them to have so many pins?
Thank you

 

Because the interface was a parallel or SCSI port.

https://en.wikipedia.org/wiki/Parallel_port


Regards, Dana.

 

DanDak is right, and the reason that there were more circuits is that much more was done in hardware instead of software. And that was because the IC devices were much less complex than they are today. If you look at the printer parallel interface specification and it's history, it was originally created for a printer with a bunch of solenoids that made the letters. At that time it was known as "the Centronics Interface", and that was one of the very early line printers. The standard worked and so everybody used it. Now the USB interface was created because windows used one driver to interface with different programs. What you may not know is that to make the USB connection work there is a whole lot of code executing constantly, while the parallel interface is interrupt driven so that the computer can do other things while not printing. I won't bore you with the history of the serial port, RS232, but it goes back to when there were just a few computers connected to lots of terminals by cables and modems.

 

Hi folks. Hope all is well. Can some one please tell me why in the olden days, computers had connectors with 16,28, 20 pins? My printer, today, has only one USB cable going into the tower. ( 2 for power and 2 for data and life is good). But in the olden days they had like tons of pins.
What technical need necessitated them to have so many pins?
Thank you

Speed.
Many pins can do the work much faster than 2 pins.
Think of the highway traffic analogy. A six-lane highway can handle more traffic than a single-lane road.

 

Of course, MrChips is right, with the qualifier of "all other things being equal" , which, in the case of computer stuff, nothing ever is. Processor clocks and buss clock speeds are many orders of magnitude faster now, and they were much faster even ten years ago, then when those interconnect standards were created.
But the Universal Serial Buss, USB, was not created for that reason, but rather as a marketing gimmick to make it easier to connect accessories, and also to make a whole generation of computers obsolete. And it succeeded in doing that. The downside is that the USB system is not interrupt driven, and so the host does not sleep, because the USB system does not deliver a wake-up. That matters in a battery powered system.