75
votes
Accepted
How many port adapters, and which ones can be stacked up and actually work?
None of them will do anything you expect. At all.
The green one is a USB to PS/2 converter, it is a wire converter rather than signal converter. It will only work if the device you plug into it can ...
- 92.7k
61
votes
Accepted
How do I transfer data between two old PCs using parallel or serial?
You can send data/receive data over the serial port using a null modem cable, or adapter with a serial cable. However, odds are high that you dont have one. On top of that, you will need to install ...
- 73.3k
29
votes
How to view serial COM ports but not through Device Manager
I know the question has been answered, but this is another method.
In command prompt, use:
chgport
in windows Vista and up. Lists your ports and which device they are.
- 309
23
votes
How many port adapters, and which ones can be stacked up and actually work?
To answer the "at what point does it stop working" part, it depends what is being converted.
I personally have an old AT keyboard, into a AT/PS2 converter, which connects to a PS2/USB converter and ...
- 2,469
22
votes
How do I know which /dev/ttyS* is my serial port?
See which UARTs where detected in /proc/tty/driver/serial. A line with uart:unknown means: nothing detected (and likely not existent).
# cat /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: ...
- 592
19
votes
Is there any way to check which baud rates are supported on a serial device?
New version august 2023:
As new source tree has splitted termbits.h into termbits-common.h and termbits.h
Little bash script:
From sawdust's answer, there is my solution:
for bauds in $(
sed -r 's/...
17
votes
Accepted
Putty refuses to open serial ports and just dings
OK, this one is rather stupid: I forgot to select the "Serial" radio-button on the Session tab and went straight to the Serial tab. Putty was still expecting an SSH connection and dinging because no ...
- 9,377
15
votes
Converting the /dev/ttyUSB to com port to use it with Wine in Linux
Starting from Wine 2.8, the simple symlink-editing method of configuration doesn't work. One has to configure COM ports by editing Wine registry. From Wine User's Guide/Other Things to Configure/...
- 1,650
14
votes
Accepted
Linux tells me a serial port is in use, but it isn't
There is probably no real usage of the line, but a permission issue.
quick and dirty way to test for me was to execute:
ls -la /dev/ttyUSB0
sudo chmod 666 /dev/ttyUSB0
and retry cu. If it starts ...
- 264
14
votes
How to view serial COM ports but not through Device Manager
You can also run the following from cmd.exe prompt
reg query HKLM\HARDWARE\DEVICEMAP\SERIALCOMM
And here is an open source utility to do the same and more:
https://todbot.com/blog/2012/03/02/...
- 315
14
votes
Accepted
Serial console login on OSX
After much fiddling around, I finally figured out the right combination of things to use for a fully usable terminal.
tl;dr: FTDI-based usb/serial adapter, terminal set to VT220 with flow control both ...
- 4,734
12
votes
Wrong newline character over serial port (CR instead of LF)
If using picocom, it's a matter of mapping the serial output from CR to CR+LF.
Example:
picocom /dev/ttyS0 --baud 19200 --omap crcrlf --echo
Actually able to send commands to the device now!
- 239
11
votes
Accepted
Linux connect from host to VirtualBox Guest over virtual serial port
First Setup Serial Console Setting in Host OS.
In virtualbox setting,
serial Ports --> Port 1
Port No. COM1
Port Mode - Host Pipe
connect to existing pipe/socked - UNCHECKED
Path/Addess: /tmp/vbox
...
- 126
10
votes
Accepted
Are the start bit and the stop bit(s) optional in serial communication?
Are the start bit and the stop bit(s) optional in serial communication?
No.
Presuming RS232 (or a TTL variant thereof).
Consider each "direction" independently, ignoring flow control lines. There ...
- 20k
8
votes
How to view serial COM ports but not through Device Manager
Using mode most of the time I don't see the devices that are not connected.
I prefer to use this solution with Python:
python -c "import serial.tools.list_ports as ls; print([p.device for p in ls....
- 303
8
votes
How many port adapters, and which ones can be stacked up and actually work?
I believe the picture shows a general RS-232 full-size DB25 COM port, and not a parallel port. Technically the stack-up should work with a special USB/PS/2 compatible mouse, which operates in LS USB ...
- 12.7k
7
votes
How to view serial COM ports but not through Device Manager
wmic https://docs.microsoft.com/en-us/windows/desktop/wmisdk/wmic is a
windows command line utility to get system information.
If your serial port is virtual created by some driver through USB ...
- 71
7
votes
Piping from serial port on Mac OS X
I used to
(stty speed 115200 >/dev/null && cat) </dev/cu.usbserial-FTB3VVRF | tee serial.log
when I wanted to pipe from serial.
6
votes
Accepted
Wrong newline character over serial port (CR instead of LF)
I guess by “enter” you mean the Return key of your keyboard,
probably labeled ↵.
Short answer:
The reason why putty, minicom and screen send CR when you hit
Return is because the Return key actually ...
- 251
6
votes
C program cannot open serial port on OS X when user is member of 'wheel'
Since I am a Mac OS X user, I added myself to the 'wheel' group based on this answer:
sudo dseditgroup -o edit -a $username_to_add -t user admin
sudo dseditgroup -o edit -a $username_to_add -t user ...
- 174
6
votes
How do I transfer data between two old PCs using parallel or serial?
Before trying out the "hardcore" no-extra-tools method I describe below, check if your Optiplex has a PATA port available inside - in which case, likely all you need is an adapter for a 2.5" PATA ...
- 780
6
votes
Accepted
How do I enable serial access to a computer (not from a computer)?
I do not think adding a Serial card would do what I want to do. I dont want to access serial connections from this server, I want to access this server via serial.
That's literally the same thing. ...
- 454k
5
votes
Linux tells me a serial port is in use, but it isn't
Serial devices privileges are granted to members of the dialout group. To get connected to /dev/ttyS0 I added the current user to the group using:
sudo adduser <username> dialout
- 51
5
votes
Accepted
Serial over USB 2.0. Is it really faster than standard serial?
Serial over USB 2.0. Is it really faster than serial?
Your terminology is sloppy.
"Serial over USB 2.0" could refer to using USB-to-RS232 adapters, or refer to CDC/ACM.
Your last reference to "serial"...
- 17.8k
5
votes
What is the Communications Port (COM1) in Windows 7?
Ensure that the COM port isn't disabled in the BIOS of your PC. You may also need to configure the COM with terminal emulation software with appropriate settings which the connected devices both use ...
5
votes
VirtualBox can't connect to host serial port VERR_FILE_NOT_FOUND
The issue I was having is apparently using a port above COM9 requires special naming conventions. For COM1-COM9 you can just enter that into the Host path/address. COM11-COM256 need to be addressed by ...
5
votes
Trying to read a serial port, device or resource busy
Sometimes just lsof /dev/ttyUSB0 is insufficient and you need sudo lsof /dev/ttyUSB0 to see which process is using the file/port.
For example, with just lsof /dev/ttyUSB3 I don't see anything, but ...
- 115
5
votes
Accepted
Is it possible to pass PCI express data signals via an express card USB 3.0 adapter?
Is there any software method (e.g. changing USB host controller) to only pass or proxy the raw data signals to the parent PCI express bus, so that my computer recognizes it as a PCI device.
In theory ...
- 454k
4
votes
How to send a BREAK on a serial port from command line in Raspbian Linux?
I believe the current Raspbian still doesn't come with screen either. If it did, you could run screen /dev/ttyWhatever then hit Ctrl-a b. Ref.
A break is specific to serial interfaces, and does not ...
- 451
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