DVD Demystified

32
Figure 2.4
Tape head
comparison
Chapter 2
For magnetic tape, raising the speed at which the tape moves past the
head increases the amount of information that can be recorded in a given
period of time, but the amount of tape required quickly becomes preposterous.
Nevertheless, in 1951, Bing Crosby Enterprises demonstrated a commercial
videotape recorder that used tape traveling at 100 inches per
second (almost 6 mph) across 12 heads. A few similarly cumbersome and
very expensive systems were developed for television studios, but their high
price tags barred them from wider use. The “eureka factor” did not arrive
for another 10 years until engineers at Ampex hit on the idea of moving the
head past the tape in addition to moving the tape past the head. A revolving
head can record nearly vertical stripes on a slow-moving tape, greatly
increasing the recording efficiency (see Figure 2.4). The first helical-scan
videotape recorder appeared in 1961, and color versions followed within a
few years.
Videotape recording was first used only by professional television studios.
A new era for home video was ushered in when Philips and Sony produced
black-and-white, reel-to-reel videotape recorders in 1965, but at
$3000, they did not grace many living rooms. Sony’s professional 1/4-inch Umatic
videocassette tape appeared in 1972, the same year as the video game
Pong. More affordable color video recording reached home consumers in
1975 when Sony introduced the Betamax videotape recorder. The following
year JVC introduced VHS, which was slightly inferior to Betamax but won
the battle of the VCRs because of extensive licensing agreements with
equipment manufacturers and video distributors. The first Betamax VCR
cost $2300 (over $6700 adjusted for inflation), and a 1-hour blank tape cost
$16 (over $46 in today’s dollars). The first VHS deck was cheaper at $885
(equivalent to more than $2500 today), and Sony quickly introduced a new
Betamax model for $1300, but both systems were out of the financial reach
of most consumers for the next few years.