StarTech.com 10 ft Cross Wired DB9 to DB25 Serial Null Modem Cable - F/M - Null Modem Cable - DB-9 (F) to DB-25 (M) - 10 ft (SCNM925FM)

I bought this cable to interface an old computer with a COM port to an old laser CNC machine with a COM port which needs to be null, or receive and transmit crossed over.This is indeed a null modem (RS232 crossover) cable. Previously I was having to use a straight through cable and a Belkin null modem adapter. The adapter was large and added excess weigh and length sticking out of the machine.One of the reviewers here stated that this was not a null RS232 cable because pins 2 and 3 on the DB-9 connector went to pins 2 and 3 on the DB-25 connector. If both ends were a DB-9 or DB-25 that would be true, but in this case pins 2 and 3 functions (RXD ad TXD) between the two connectors are already flipped. In a straight through cable, pin 2 goes to pin 3 and pin 3 goes to pin 2. Not intuitive, but that's the way it is. Some machines are null cross over, but may have added configuration requirements.

I needed this cable urgently to work on an old but critical device. Was unable to locate at tech stores locally. Ordfered nand it came quickly. Great product. Saved me a lot of headaches. worked perfectly. Thank you A+

This is a good cable - well built and comes in a old school grey color - perfect if you want to relive the computing of the 80s and 90s. More than the aesthetics, it is also good if you want to connect some equipment from that era.While StarTech does not provide a pinout, I can confirm that the cable works as a plotter cable (you can google plotter cable pinout to see how those are wired). Not sure about hardware handshaking as my HP 7574A plotter does not use it.

Works perfectly with my Amiga computer

We were having problems with this cable and decided to ohm it out. For this cable, pin 3 of the DB25 went to pin 3 of the DB9 and pin 2 of the DB25 went to pin 2 of the DB9. So, they are not crossed over as stated in the very confusing description. I ordered a DB9 cross-over connector to fix this.

This critter is a Blast from the Past.Where to begin...?First off, it has a cable - nothing today uses a "cable"Bluetooth, WiFi, Network connections, USB connections, near field connections, The Force.Ok, technically USB and Network connections have cables, too - but, you get the idea.Second, Nothing new has a 25 pin or 9 pin Cannon connector on it.So, obviously, we are talking seriously antiquated equipment here.Surprise - the equipment that I wanna talk to is 30 - 40 years old, phase 4 obsolete = the OEM won't admit that they built it.Yeah!! Our lab manager scored a piece of equipment on E-Bay, with (drum roll please) an RS232 communication port.Not just any RS232 port (like the dominant 9 pin port).He went the extra mile to find sumthun with a 25 pin RS232 port.Our USB to RS232 adapters are 9 pin...You can see where this is going.The RS232 communication protocol was the driving force for creating USB connections.RS232 does everything - whilst usually not working - at all.Between Baud Rates, Parity Bit, Stop Bit, hardware handshaking options, etc.. - oh, and, don't forget the null cable option, it was virtually impossible to figure out how to get two pieces of equipment to talk.Using other adapters and programmable jumpers on additional adapters, I managed to get a kluge cable to work.This particular product implied that it would do the same thing as my cobbled kluge.It did.It is well made.It should provide better ease of use than my rats nest cable.BTW - it is mentioned in the sellers information - I'll repeat it anyway.This is a Null RS232 cable.The Send Receive lines on the 9 pin and 25 pin connectors are rolled.

Needed these for a Point of Sale system that uses older Serial receipt Printers.This worked perfectly and I highly recommend them

From other reviewers it looks like a certain amount of randomness as to which pin is connected to which.In my case the DCD pins are not connected to anything instead of their own DSR. You can probably get away with that but come on. Worse, the RTS and CTS are directly connected instead of crossing over -- no handshaking for you!Okay, if you're just using XON/XOFF software control it would probably work if you're feeling lucky.