[rescue] Serial console - break "filtering" connection - resistor method

[John-Paul Stewart]

On 2023-10-16 19:31, vom513 via rescue wrote:
> 
> Seems to have a much more in depth discussion on this issue.  Pin 25
> does indeed seem to be “dead air” on this machine and presumably others
> more recent.

Indeed.  Pin 25 was used for -5V in the Sun3 era according to:

http://www.sunhelp.org/faq/sunref3.html

Search for VERR to find the references.

Pin 25 was also used, but for a totally different purpose, on some of
the later machines that had two serial ports in one DB-25 connector
(such as the SparcStation 10 & 20).  But that doesn't apply to your IPX.

https://www.sunhelp.org/unix-serial-port-resources/serial-pinouts/