Hardware manual

Table of Contents
Serial HOWTO...................................................................................................................................................1
David S.Lawyer [e-mail] original by Greg Hankins.....................................................................1
1. Introduction..........................................................................................................................................1
2. Quick Help...........................................................................................................................................1
3. How the Hardware Transfers Bytes.....................................................................................................1
4. Serial Port Basics.................................................................................................................................1
5. Multiport Serial Boards/Cards/Adapters..............................................................................................2
6. Servers for Serial Ports........................................................................................................................2
7. Configuring Overview.........................................................................................................................2
8. Locating the Serial Port: IO address, IRQs..........................................................................................2
9. Configuring the Serial Driver (high-level) "stty"................................................................................2
10. Serial Port Devices /dev/ttyS2, etc.....................................................................................................2
11. Interesting Programs You Should Know About................................................................................3
12. Speed (Flow Rate)..............................................................................................................................3
13. Locking Out Others............................................................................................................................3
14. Serial Communications Programs And Utilities................................................................................3
15. Serial Tips And Miscellany...............................................................................................................3
16. Troubleshooting.................................................................................................................................3
17. Interrupt Problem Details...................................................................................................................4
18. What Are UARTs? How Do They Affect Performance?..................................................................4
19. Pinout and Signals.............................................................................................................................4
20. Voltage Waveshapes..........................................................................................................................4
21. Other Serial Devices (not async RS-232)..........................................................................................5
22. Other Sources of Information............................................................................................................5
23. Appendix A: Very Obsolete Hardware/Software..............................................................................5
1. Introduction..........................................................................................................................................5
1.1 Copyright, Disclaimer, & Credits......................................................................................................6
Copyright...........................................................................................................................................6
Disclaimer.........................................................................................................................................6
Trademarks........................................................................................................................................6
Credits...............................................................................................................................................6
1.2 New Versions of this Serial-HOWTO...............................................................................................6
1.3 New in Recent Versions.....................................................................................................................7
1.4 Related HOWTO's, etc. about the Serial Port...................................................................................7
1.5 Feedback............................................................................................................................................7
1.6 What is a Serial Port?.........................................................................................................................7
2. Quick Help...........................................................................................................................................8
3. How the Hardware Transfers Bytes....................................................................................................8
3.1 Transmitting.......................................................................................................................................9
3.2 Receiving.........................................................................................................................................10
3.3 The Large Serial Buffers..................................................................................................................10
4. Serial Port Basics..............................................................................................................................11
4.1 What is a Serial Port ?......................................................................................................................11
Intro to Serial...................................................................................................................................11
Pins and Wires.................................................................................................................................11
RS-232 (EIA-232, etc.)...................................................................................................................12
4.2 IO Address & IRQ...........................................................................................................................12
4.3 Names: ttyS0, ttyS1, etc...................................................................................................................12
Serial HOWTO
i