The composite video signal coming from the Apple IIe is not stated to be an
NTSC-compliant signal. The signal coming from the video-out port is only
considered NTSC-compatible video. "Compatible" means that generally the Apple
IIe video will work with an NTSC device, although it may not work in all
situations. Specifically, the Apple IIe video signal should work with all NTSC
display devices.
When the Apple II was first designed, economy was of great importance. The
video circuitry was built with as few parts as possible. In the design
process, it was discovered that certain portions of the NTSC broadcast
specification could be omitted, yet still display a color image on a standard
television set. The one element that affects the described situation is color
burst. The Apple IIe does not contain the color burst element of the NTSC
video signal. By modulating other portions of the video signal, the Apple IIe
simulates this missing information and allows an image to be produced on a
television. To provide a consistent color video image for video tape, this
color burst needs to be present.
In summary, the Apple IIe composite video signal was designed for display
proposes, not for videotaping purposes. The Apple IIe composite signal is
close to the NTSC specification and allows the video signal to be displayed on
television screens. This, however, does not indicate that the signal can be
recorded. Since the signal is similar to the full NTSC specification, video
sometimes records properly on videotape with certain VCRs. In other
environments, the signal may not record at all. The capability to record a
monochrome image falls between these extremes.
To have a true NTSC signal designed for videotaping, the Video Overlay Card is
required.