Garbled sysinst TUI after successful system probe

[kat%electronic-quill.net@localhost]

Hi all,

I'm trying to install NetBSD on a relatively old tower/desktop workstation, and I suspect the problem is Nvidia-related.
The initial installer menu loads fine, and pressing "1" gives the usual stream of system-probe messages, so that much works perfectly well. When sysinst tries to present its TUI, things go immediately to pot.
A couple of green and magenta horizontal lines appear over the text near the top of the screen, and the bottom quarter initially flashes with some green-on-black garbage, which is quickly replaced by slowly evolving white-on-blue garbage. I take this to be a disagreement between the GPU and the driver selected by the installer.
This machine has previously run very happily under Linux, and FreeBSD did install but *really* doesn't want to co-operate with the GPU.

The GPU is a GeForce GTX 1660 Ti (rev a1) according to FreeBSD - not recent by any means. It's connected via DisplayPort to an old 27" Dell monitor, in case that's at all relevant.

If anyone can suggest troubleshooting steps, I'd appreciate it. I do have USB-to-serial adapters, with both male and female DB9 ends, so I'm considering trying to connect to the serial port from a Linux laptop, in the hope of at least getting it installed to the point of a working CLI.


Yours in hope,
Kat