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I installed new daughter cards for a parallel port and a telephone modem on the PCI bus of my computer. The lspci command reveals that the system sees the cards but I don't know which config file I need to edit to use these new cards. I've searched the web but have not yet found anything that helps me.

root@CLM1001-Ubuntu:~# lspci | grep 04:
04:05.0 Parallel controller: Device 1c00:2170 (rev 0f)
04:06.0 Multiport serial controller: PCTel Inc HSP MicroModem 56 (rev 02)

This is an old computer with a video card that does not support a newer linux kernel, so I am stuck running Ubuntu 14.04 LTS.

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  • Look at sudo lshw, and look at /dev/ directory and the startup logs sudo journalctl -b 0.
    – waltinator
    Commented Apr 2, 2022 at 0:41
  • There's no particular "config file" to edit. The bus and devices should be detected on boot. You might have to add your $USER to some groups. What flavor of Unix/Linux?
    – waltinator
    Commented Apr 2, 2022 at 0:45
  • @user174174 Sorry it took me so long to accept your edit. My Ubuntu computer is experiencing issues with this website not accepting mouse clicks and "#noredirect" appended to the address line. I had to visit from an iMac to accept the answer to this question and to accept your edit of the question itself. Commented Apr 3, 2022 at 3:48

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The PCI vendor:product ID of the parallel port card is 1c00:2170. The fact that the ID number is displayed without using lspci -n or lspci -nn indicates that the vendor is not included in the system's PCI ID database. That's not a good sign.

This webpage mentions the vendor ID:

1c00 is not a listed PCI vendor ID. 1C00 is the Vendor ID used by WCH (not assigned by pcisig).

WCH seems to be a Chinese vendor of various adapter cards. The fact that they seem to have just grabbed a vendor ID without officially registering it with the PCI-SIG is not a good sign, either.

Even the newest stable kernel (5.17.1 at the time of this writing) only supports two product IDs with this vendor ID: those would be 3050 and 3250. The product ID 2170 is completely unknown.

And even those two product IDs were added to the kernel in 2018, so the original kernel of Ubuntu 14.04 LTS probably would not have even those.

If the card came with a Windows driver (or a working download link for one), then reading the *.INF file of the Windows driver might provide some clues about the card. You might also see if there are any visible markings on the main chips on the card, and Google them if you find any; if it turns out the card uses a chip that is already known to Linux, WCH might be using a copy of an existing card design.

If it turns out that your card is a copy of a PCI parallel port card that is already supported by Linux, creating a kernel patch to add support for it could be a fairly simple matter of basically copying the relevant lines defining the details of the supported card to make a new entry in <Linux kernel source root>/drivers/parport/parport_serial.c and changing the PCI IDs of the new entry to match your card. Then you would have to compile your own kernel and test your changes.

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    Recompiling the kernel is way out of my comfort zone. I returned the card to Amazon. Thank you so much for the well-informed answer. Commented Apr 3, 2022 at 3:26
  • Hahaha! Yes, though years ago I did some slightly edgy things with the operating systems on my machines, the mere phrase "recompiling the kernel" gives me the creeps. :) Commented Apr 3, 2022 at 4:01

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