RS232 Female/Male Null Modem Cable DB9 FTA Cross/Straight Connection 9 Pin COM Data Cable
Null-Modem Serial Cables
Building the Null Modem Cable
Serial Port and Modem Cables
NC-9F9F-6FT Null Modem Cable | WTI - Western Telematic, Inc.
Should I Use Null Modem or Straight Through Serial Cables? - NI
Amazon.com: CableWholesale Null Modem Cable, DB9 Male to DB9 Female Serial Cable, UL Rated, 8 Conductor, Beige, DB9 Serial Null Modem Cable Male to Female, 25 Feet : Electronics
Tech Stuff - RS232 Cables and Wiring
File:D9 Null Modem Wiring.png - Wikipedia
Amazon.com: USB to RS-232 DB9 Female 9 Pin Null Modem Rollover Serial Adapter Cable for Windows,Linux MAC OS (Null Modem) : Electronics
Should I Use Null Modem or Straight Through Serial Cables? - NI