80-column text is usually difficult to read when displayed on a composite
color monitor.
The major problem is the bandwidth of the monitor: to properly display
40-column monochrome information requires a minimum of 4 MHz bandwidth.
Television receivers are near the bottom end at 4.5 MHz. Monochrome
monitors are usually specified with a bandwidth of 12 MHz, for sharpness
with an 80-column display. If color information is displayed too, the
minimum bandwidth doubles, to 24 MHz. The problem with many televisions
that have direct video inputs is that they are still limited to the
television bandwidth of 4.5 MHz, which is inadequate for displaying
80-column information.