Ah Slackware, the first time that I learned software could damage hardware. It has the option to also configure hsync on your CRT monitor, and if said monitor didn't correctly validate the range it would permanently fuck it up.
I learned that lesson as a 12 year old in the early 90's on an original IBM PC 5150 with a 5151 monochrome monitor, fucking with TSR's in DOS 3.1. It must've made the graphics card change timing modes and the monitor immediately blew a fuse. My dad then soldered in a fuseholder so the fuse in the monitor can be replaces as needed.
Out of fear of doing further damage, I did stay away from the particular TSRs that had any relation to changing video timing modes and it didn't happen again.
X11 used to require very cumbersome MANUAL configuration, where you would specify the exact parameters of your keyboard, mouse, monitor, and other peripherals. If you accidentally ended up overclocking your monitor it would melt. For at least a decade, it has been able to run with no configuration file at all, but in the 90s/early 2000s you had to produce a unique >75 line xorg.conf file for your specific hardware.