🚀 go-pugleaf

David J N Begley <david@melba.nepean.uws.edu.au> wrote:
> 
> For example, I'll need a serial cable of some sort to connect the dumb 
> terminal to the SPARC - but on what port?  One of the two 25-pin ports 
> marked "A" and "B", I assume?  So here I'd just need a 25-pin male to 
> 25-pin male serial cable (oh, something about a break-out box was 
> mentioned by the rotten sods who dropped this on me - why might this be so?).
>

Assuming this is same as on SS10, Sun have combined 2 (TWO) serial ports 
into 1 DB25 socket, thus saving about $4, & costing millions around
the world in support calls.

The DB25 marked A/B is both serial port A, and serial port B.
Depending on which standard version of unix you use, this will be
/dev/ttya & ttyb, or /dev/terma & termb, etc etc

Port A uses the normal 5 asynch signals on the normal pins 
GND, TX, RX, DCD, DTR, DSR, CTS. A fairly standard cable will connect
a dumb terminal to port A.

Port B is optional, to use it you need a special cable, which can
be bought from Sun for US $100 + 3 weeks delay, or can be wired up
cheaply. the B port uses "spare" pins to carry the basic signals 
only & does not have full modem control. By "spare" I mean signals
normally only used in synchronous modes e.g. Clock in, clock out, etc.

Sun had no more room on the back panel, hence the kludge to save space.
If you're still stuck I can get the wiring diagram next week 
but do not have it with me now.