Vertical deflection is via an LM386 driving a hand wound impedance matching transformer. The high voltage flyback transformer and its associated driver circuit were kept from the original CRT ...

Also called "refresh rate," vertical scan frequency is the number of times a CRT was redrawn per second. Measured in Hertz, CRTs ranged from 56 to over 100 Hz, but at least 70 was recommended to ...

In March 1989, alongside the Macintosh IIcx, Apple introduced a 15” vertical CRT with a resolution of 640 x 870 pixels. It was aimed squarely at the desktop publishers that had become the Mac’s bread ...

which is fairly true for CRT and plasma screens. However, viewing angles differ between LCD and front and rear-projection screens. Horizontal and vertical angles are often not the same.