Amazon.com: CableWholesale DB9 to DB25 Serial Cable, 9 Conductor 28 AWG Single Shielded RS232 Serial Cable, DB9 9 Pin Male to DB25 25 Male Connector Serial Cable, Beige, 6 Foot : Electronics
Amazon.com: 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) : Electronics
Do-It-Yourself Kit, DB25 Male / DB9 Female - DIY259MF
CC510-06 - 6ft DB9 Male to DB25 Male Cable
Amazon.com: StarTech.com DB9 to DB25 Serial Cable Adapter - F/F - Serial adapter - DB-9 (F) to DB-25 (F) - AT925FF, Beige, 1 Count (Pack of 1) : Electronics
RS232 cable information
How To Wire A DB25 Connector for Audio - YouTube
CC312-20 - 20ft DB9 Female to DB25 Male Serial Modem Cable
DB9 and DB25 RS232 Serial Printer to Cat5 RJ45 Adapters and Cables