Re: [M100] An interesting DB-25 right angle connector

[B 9]

On Tue, Jul 28, 2020 at 5:47 AM Brian White  wrote:

> A gender-changer does not simply make the existing female pins male, it
> also relocates all pins to their mirror image locations. That's why the
> mini gender-changers always flip the D shape upside-down from one side to
> the other.
>

Ah! So does that mean one could get an upside-down male connector to
replace the existing female connector?

A lot of the plain through-hole stuff I saw didn't look like it had the
> lead length to make a solid friction fit into the port and still sit nice
> and flush against the top edge of the T like mine does, but that Molex with
> the nice long leads looks like it might do it if can transplant the
> mounting greebles from the old one.  I haven't taken measurements yet but
> it looks like a fairly close match by eyeball.  Nice find!
>

I had thought it looked like a close match, and I think it is, but I
realized there's an optical illusion happening. The leads only look long in
your image (and on the Molex) because they lack a piece of plastic most
others connectors have. I think they might all be the same length. (Of
course, you'd still need one with an upside-down male connector).

—b9

Re: [M100] An interesting DB-25 right angle connector

[Joshua O'Keefe]

On Jul 28, 2020, at 5:47 AM, Brian White  wrote:
> A female connector is a mirror image of a male

Brian, thank you for taking the time to walk me through this in detail.  As 
someone decidedly not mechanically inclined it is educational and helps me put 
the pieces of the puzzle together.

Re: [M100] An interesting DB-25 right angle connector

[Brian White]

It IS standard DTE pinout, merely female.

A female connector is a mirror image of a male connector.

Look at the numbers on the pins, not their physical location.

A gender-changer does not simply make the existing female pins male, it
also relocates all pins to their mirror image locations. That's why the
mini gender-changers always flip the D shape upside-down from one side to
the other.

Take a female connector, look at it's face with the longer row of pins on
top, and find pin #1 (top-left I think). Now imagine a male connector is
inserted. That pin#1 position is also pin#1 on the male connector. Now
imagine taking the male connector out and looking at it's face. Where pin#1
is top-left on one connector, it's top-right on the other.

-- 
bkw

On Mon, Jul 27, 2020, 12:58 PM Joshua O'Keefe 
wrote:

> On Jul 27, 2020, at 6:41 AM, B 9  wrote:
>
> Molex 1731090178
> 
>
> Wouldn't you need to change the wiring since the pins go from
> left-to-right instead of right-to-left?
>
>
> A lot of the plain through-hole stuff I saw didn't look like it had the
> lead length to make a solid friction fit into the port and still sit nice
> and flush against the top edge of the T like mine does, but that Molex with
> the nice long leads looks like it might do it if can transplant the
> mounting greebles from the old one.  I haven't taken measurements yet but
> it looks like a fairly close match by eyeball.  Nice find!
>
> I wasn't aware the T's serial port was wired backwards, though.  I thought
> it was just female where DTE is customarily male. Maybe I should continue
> to stick with what I have since it works even if the sequence of adapters
> between any given two devices can get a little unwieldy.
>

Re: [M100] An interesting DB-25 right angle connector

[Joshua O'Keefe]

On Jul 27, 2020, at 6:41 AM, B 9  wrote:
> 
> Molex 1731090178  
> 
> Wouldn't you need to change the wiring since the pins go from left-to-right 
> instead of right-to-left?

A lot of the plain through-hole stuff I saw didn't look like it had the lead 
length to make a solid friction fit into the port and still sit nice and flush 
against the top edge of the T like mine does, but that Molex with the nice long 
leads looks like it might do it if can transplant the mounting greebles from 
the old one.  I haven't taken measurements yet but it looks like a fairly close 
match by eyeball.  Nice find!

I wasn't aware the T's serial port was wired backwards, though.  I thought it 
was just female where DTE is customarily male. Maybe I should continue to stick 
with what I have since it works even if the sequence of adapters between any 
given two devices can get a little unwieldy.