Help identifying computer cable

[newbie2wood]

Question for the computer literate, I find a DB9 to DB25 cable in my house but there are only nine pins on the DB25 end. The DB9 end also has 9 pins. I thought I was converter cable but pins 20 and 22 are not used. Does anyone knows what is the purpose of this cable? It looks like a specialized cable. I would hate to toss it out and find out I need it later.

[LCHIEN]

pins 20 and 22 of the 25-pin connector are seldom used - Data Carrier Detect and Ring indicator. Useful mostly with a true modem.
It could be wired 1 to 1, and 2 to 2, ... 9 to 9. But that would not make a good serial cable.
Best is to buzz it out. with an ohmeter.

From your picture that looks like it has a removable shell and not a molded end. You can take the shell off and see how its wired, and even move the contacts from one to another position in the body and make it anyway you want. It does take a special pin extractor since the contacts have barbs that keep them from being pulled out.

[Darth_Brehm]

To save on space and cost many serial ports were only the 9 pin variety. However, lots of devices (joysticks, printers, etc.) still had the 25 pin connector. I am assuming you bought this for just such a device.

My hunch is that you would be hard pressed to find any computer these days with either type of serial port. Basically everything has transitioned to USB or other newer port designs.

I would not hesitate to donate that to the Goodwill for a "healthy" tax write-off.

[Stytooner]

You can still buy off lease and refurb computers with both serial and parallel ports in the MB.
That is a good thing for cnc builders.
All my cnc machines require a PP, but my plasma cutter also needs the serial to operate the THC.

I would say that is some sort of specialty adapter cable as mentioned.

[dbhost]

For what it's worth, most 64 bit computers I have worked with do not use either serial or parallel ports. Yes that looks like a spacialized serial cable, but for what, who knows? Whatever it is, well it's old, ancient in tech terms...

For the most part, on legacy devices that require serial communications, I have used either serial port add in cards, or usb to serial converters. Honestly the converters are more often than not flaky...

I believe it is either made by Syba, or Rosewill, but I have had pretty good luck with the Serial / Parallel combination controller cards. Linux support is top notch, however Windows 7 device drivers for parallel and / or serial devices is almost non existent...

[woodturner]

To save on space and cost many serial ports were only the 9 pin variety. However, lots of devices (joysticks, printers, etc.) still had the 25 pin connector. I am assuming you bought this for just such a device.

+1 on that - looks like a joystick cable.

Let me know if you need a joystick to go with it, can make you a great deal ;-)

[newbie2wood]

Thanks for all the info. I do not recall ever using this cable for a joystick or anything. I guess it off to Goodwill for the tax write-off.