16 Nov
2008
16 Nov
'08
3:20 p.m.
Tony Duell wrote:
And the PCjr serial port is at RS232 levels anyway.
The PCjr seiral cable
is just a cahle, no intenral componnets (I have the PCjr TechRef with
schematics...)
Good point - I'm looking in the TechRef and see that now too. I don't
know why I was assuming TTL logic levels.
If it was used wit ha PCjr, then I would guess that
the PCjr was
connected to the RS232 side of this coverter, and some other device,
using a TTL level serial port, was connected to the 20 pin header.
I can't think fo anything offhand that would have such a port. It might
have been something very specialised (say to control or program some
measuring instrument or something).
-tony
Still clueless. The RS232 side of this device is male, and the serial
adapter cable for a PCjr is also male, so it would have needed a gender
changer to work in that arrangement.
Can I throw something stupid out here? I'm making an assumption that it
was for the serial port. However, if it's just converting voltage
levels is it possible that it was driven by the parallel port? That's
TTL level. (I have no idea what they were attaching to the other side ..)
Mike