[Coco] serial ports and printers, oh my was Re:Coco serial cable

[Tim Fadden]

Willard Goosey wrote:
> On Sat, Aug 29, 2009 at 09:08:59PM -0400, Aaron Wolfe wrote:
>   
>> Pin 19 is defined in the standard as secondary request to send, which
>> makes you wonder why so many used pin 11 for this. 
>>     
>
> The way I understand the RS-232C standard, is that there's two ports
> on one DB-25 connector, and pin 19 is rts for the second port.
>
> Not that I've ever seen a DB-25 wired like that.  The closest I've
> ever seen is one of my terminals puts a current loop on some of those
> pins.
>
> Still, it's something to keep in mind.  I never know when what weird
> computer hardware will end up in my doorstep.
>
> Willard
>   
Some Sun Microsystems machines use a single db25 that has two rs232 
ports on it, just as you speak.  They make a splitter y cable to use 
both of them. Or if you connect a cable directly you get one port.

Tim Fadden