External clock for P-I serial port?

[Vernon Schryver]

In article <CHRISA.90Dec13145507 at beldar.ma30.bull.com>, chrisa at beldar.ma30.bull.com (Chris Anderson) writes:
> 
> Is it possible to provide an external clock for either or both of the
> serial ports on the personal Iris? 

No.

> The manuals indicate that ioctl can set an external clock mode,
> but the signal is undocumented. Is the clock signal a spare pin on the 
> D connector, and if so, what should drive it?


Which manual is this?  It should not say that, since it is wrong.  Have the
"EXTA" and "EXTB" speeds of /usr/include/termio.h and termio(7) been
misinterpreted?   In some distant and ancient universe, they may have
referred to external clocks.  Now they are the same as 19.2 and 38.4.

As chapter 10 of the "IXIX System Administrator's Guide" says, the only
signals that do anything interesting on the standard SGI DB-9 are
2,3,4,5,7,8,and 9/20.  (or RD,TD,RTS,CTS,SG,DCD,DTR)


Vernon Schryver,   vjs at sgi.com