Hard to date but I think late 60's .
We had 2 computers in high school about 1972. One was in the office
for tracking grades, attendance, & scoring some tests.
The other was in the computer club. It was kept in the math class.
DEC was headquartered in the next town Maynard, Ma. & they donated
it. IIRC it only had a teletype type interface. I had zero interest in computers
but the DEC employees were well off so I made much $$ off them
73 Zeno
LFOD !