Classify all the words into the categories below MICROCOMPUTER (7) MAINFRAME (1) SUPERCOMPUTER (3) SPECIAL PURPOSE (2) GENERAL PURPOSE (3) ANALOG (2) DIGITAL (2)

handheld computer
wrist watch
wall clock
ENIAC
Columbia System
Cray-2
netbook
local area network server
laptop
IBM Z-series server
tablet
personal computer
HPCx system
speedometer
alarm clock
microwave oven
video camera
smartphone
Colossus
Z3 computer

Why were most movies from the late 1890s until the early 1930s only filmed in black and white? there were only a few people who could afford the technology to produce color motion pictures back then. audiences did not want color motion pictures until later. the film used to make color motion pictures often overheated, which was a safety hazard, so it was generally not allowed. color films had to be hand-colored, frame by frame.