Wow, an actual VT-100! Have you tried "smooth scrolling" (aka
"barf mode")? AFAIK none of the emulators (or "VT100-compatible"
iron, for that matter) ever bothered to replicate this (for which
hackers prone to motion sickness remain grateful 🤢)
/Frew
P.S.: Fond memories of the USENIX where Rob Pike, in a talk
describing the Blit, announced "and [pause] it is NOT VT-100
compatible", to thunderous applause. A lot of termcap tweakers in
that audience...
secured a VT100 for a reasonable price