On 01 Jul 2025 16:31:35 -0700, Peter wrote in message
<20250701233143.07119228055@???>:

> From:    Arnt Karlsen <arnt@???>
> Date:    Mon, 30 Jun 2025 07:17:11 +0200
> > Chances are you have such cable tools ...  

>
> All I have is one or two null modem cables with DE-9 subminiature
> connectors. Should suffice to connect an old machine with a DE-9
> serial port and terminal emulator. I expect no difficulty with the
> connection and the terminal emulator.

..good.

> > if you've ever messed around flashing new firmware onto things
> > like cameras, rc radios, autopilots or laptop bios chips, etc.
>
> Zero! =8~/

..there's a first time for every thing good, we like to tell
virgins... ;o)

> I expect that tracing should begin with GRUB.
> https://www.gnu.org/software/grub/manual/grub/html_node/Serial-terminal.html

..yup.

> As mentioned previously, the machine has no built-in serial port or
> headers.

...other than a dozen usb ports... ;o)

> If a PCIe serial adapter is added, the serial port is configured as
> described here.
> https://www.gnu.org/software/grub/manual/grub/html_node/serial.html#serial
>
> Alternatively a USB adapter can be added with configuration as here.
> https://unix.stackexchange.com/questions/79838/grub-and-usb-serial-support
> More modules to load and more complex than for the PCIe adapter.
>
> With no intended offense to your preference for USB, isn't the PCIe
> adapter the simpler option?

..your machines, your null modem cables, your money, your pain,
your ass etc makes it your decision. ;o)

--
..med vennlig hilsen = with Kind Regards from Arnt Karlsen
...with a number of polar bear hunters in his ancestry...
Scenarios always come in sets of three:
best case, worst case, and just in case.