<P> In 1928, Delco, a division of General Motors, purchased Northeast Electric, and the typewriter business was spun off as Electromatic Typewriters, Inc . In 1933, Electromatic was acquired by IBM, which then spent 1 million USD on a redesign of the Electromatic Typewriter, launching the IBM Electric Typewriter Model 01 in 1935 . By 1958 IBM was deriving 8% of its revenue from the sale of electric typewriters . </P> <P> In 1931, an electric typewriter was introduced by Varityper Corporation . It was called the Varityper, because a narrow cylinder - like wheel could be replaced to change the font . </P> <P> Electrical typewriter designs removed the direct mechanical connection between the keys and the element that struck the paper . Not to be confused with later electronic typewriters, electric typewriters contained only a single electrical component: the motor . Where the keystroke had previously moved a typebar directly, now it engaged mechanical linkages that directed mechanical power from the motor into the typebar . </P> <P> In 1941, IBM announced the Electromatic Model 04 electric typewriter, featuring the revolutionary concept of proportional spacing . By assigning varied rather than uniform spacing to different sized characters, the Type 4 recreated the appearance of a printed page, an effect that was further enhanced by including the 1937 innovation of carbon - film ribbons that produced clearer, sharper words on the page . The proportional spacing feature became a staple of the IBM Executive series typewriters . </P>

What is the difference between manual typewriter and electric typewriter
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