Project: The Sound of Violence.
I have dug out the initial hardware equipment needed to prove whether the project is doable, and to prototype the hardware circuit, and to provide hardware-assisted debugging (flashing lights!).
First off, there is a RS-232-C port splitter, needed because the 25-pin V.24 D-shell socket on the rear panel of the SPARCstation-10 and SPARCclassic contains *two* separate serial ports; the splitter splits the two-in-one wiring into a pair of separate cable bundles, one for each port:
Notice that the cables go to RJ-45 10BaseT-style plugs, so that I can run RS-232 serial cables through existing Ethernet wiring infrastructure. This splitter cable was home-made several years ago.
Next, I will need a few RJ-45 to 25-pin D-Shell adaptors, male and female at the D-shell end:
Can you see the RJ-45 socket on the back of the lower one? These particular adaptors are wired according to my own scheme for a straight-through RS-232 connection. In my collection, there is a carrier-full-null-modem version, null-terminals (!), and a generic multi-printer-modem version, but I won’t be using such specialities here, at least for now. Ah, I remember the wierd and wacky days of V.24 serial-device signalling incompatibilities (that’s after 20milliamp current-loop went out of fashion, around 1984, and lasted until the Millenium).
To avoid a lot of experimental soldering, resoldering, resoldering, resoldering, and so on, I have dug out an old RS-232 “breakout” box (a 12V DC patch-panel with LEDs to monitor the signal-lines):
and here it is open (spot the bundle of blue patch wires):
Finally (until I have the software written and debugged) there is one piece of newer equipment needed: a longish 10BaseT Ethernet cable to carry not Ethernet signals but rather the 12V RS-232 serial signals – this cable runs between the D-shell adaptors:
and in case you were wondering, the lights are not due to the project software (which doesn’t exist yet), they are due to a standard Solaris “tip” terminal-emulation session…