RS-232 Pinouts: DB9 and DB25 Explained
Complete RS-232 pinout reference for DB9 and DB25 connectors: DTE and DCE pin assignments, voltage levels, cable limits, and the TTL mistake that damages boards.
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Serial, SCSI and legacy cabling
RS-232 pinouts, null modem cables, USB-to-serial adapters, RS-422 and RS-485, SCSI and SAS, parallel printer and telco cables.
Null Modem Cables: Wiring, Adapters and Pinouts
A null modem cable crosses TX and RX to join two computers directly. Covers DB9 and DB25 pinouts, adapters versus cables, gender changers and loopback testing.
SCSI Cables, Connectors and Terminators
SCSI cable types explained: 50-pin, HD68 and SCA-80 connectors, narrow vs wide buses, SE, LVD and HVD signalling, termination rules and length limits.
RS-422 vs RS-485: Differential Serial Compared
RS-422 is one driver to many receivers; RS-485 is a true multipoint bus. Compare distance, speed, termination and wiring, and see what damages hardware.
USB to Serial Adapters: Drivers, Levels and Pitfalls
How USB to serial adapters work, why drivers and counterfeit chips matter, RS-232 versus TTL levels, and how to get old DB9 equipment talking again.