The very first Betas recorded and played back at only one speed, 4.0 centimeters per second (1.6 inches per second). When using the original K-30 cassette that came with the machines this allowed the user to record up to thirty minutes of video. Also available was a K-60 cassette for up to sixty minutes of recording time. This speed later came to be known as the Beta one speed or . These recordings times increased when Sony introduced slower speed called Beta two (). Now the tape would travel through the machine at half the speed 2.0 cps (0.8 ips). To try and avoid confusion with the tape lengths the first two cassette sizes were changed to a numbering system. The original K-30 became the L-250. It was still thirty minutes in but became one hour in . The K-60, now the L-500, did one hour in and two hours in . A new longer length cassette, the L-750, maxed out in at three hours. But it didn't stop there. The speed was reduced one more time. This last speed, called , slowed the tape down to 1.33 cps (0.5 ips). The recording times then became L-250 maximum of 90 minutes in , L-500 three hours and the L-750 could now do up to four and a half hours. The introduction of a still longer cassette called the L-830 allowed up to five hours in and three and hours twenty minutes in . This is where the time war stopped for Beta.