From Tape to Disk: Plenty of Advances in Store

1983 marked the dawn of digital storage

Looking back at the past 20 -- year history of videodisk recording technologies for the moving image would be incomplete without first taking a glimpse at the development of the magnetic disk drive -- which is about 50-years old this year.

Magnetic recording first was proposed in 1888, some 43 years after the discovery of magnetic polarization rotation. In the early 1950s, the commercial development of storing data in a semi-permanent format was in its infancy.

The earliest method for storing data employed cylindrical drums, whereby magnetic patterns were deposited and then recovered by a device that would later become the magnetic "head." In the first generation disk drives, the heads actually contacted the surface, severely limiting the life of a disk drive. IBM engineers later floated the head above the magnetic surface, a fundamental principle that would become the mainstay methodology of the magnetic disk recording technology even through today.

The first manufactured hard disk, introduced Sept. 13, 1956, was the IBM 305 RAMAC, which stood for Random Access Method of Accounting and Control. With a storage capacity of five million characters, it required 50, 24-inch diameter disks, with an aerial density of 2 kb per square inch - as compared to gigabits per square inch today. The transfer rate of the first drive was 8.8 kb per second, and the cost for an IBM model 355-2, single-head drive, at that time, was $74,800, or $6,233 per megabyte. It was 1973 before an 8-inch floppy drive was available and 25 years before IBM would introduce the personal computer, or PC, in August 1981.

By 1962, IBM introduced its model 1301, the first commercially available 28 MB disk drive with air-bearing flying heads, which rode above the surface at 250-microinches, a decrease from the previous spacing of 800-microinches. The first removable disk pack was brought into production in 1965 (remaining popular through the mid-1970s). A year later, ferrite core heads became available in IBM's model 2314, later introduced in the first modern PCs.

The IBM Winchester drive, introduced in 1973, bore the internal project name of the 30-30 Winchester rifle and employed the first sealed internal mechanics. The IBM 3340 Winchester drive had both a removable and a permanent spindle, each with a capacity of 30 MB. The drive's flying head height had now been reduced by 47 times, from the original 800 -- microinches to 17 -- microinches.


Seagate introduced the 5.25 -- inch form factor ST -- 506 in 1980, featuring four heads and a 5 MB capacity. When IBM introduced the PC/XT, they would use a 10 MB model ST-412 drive, which set the standard for the PC-compatible future. The 3.5-inch form factor RO352 was introduced in 1983 by Rodime, which remained the universal form factor for modern hard drives through the infancy of modern mobile computers until the 2.5-inch was introduced in 1988.

The recording of moving images onto a rotating magnetic storage surface had an equally parallel development. Alongside the development of magnetic recording tape, random -- access video -- on -- demand -- predicted in 1921-was said to become available as early as 1950. The concept of recording video onto a spinning platter was demonstrated in the late 1950s, just about the same time as the first disk drive was introduced, (as well as NTSC, adopted in 1954). A rudimentary plastic videodisk was demonstrated at the Salone Internazionale della Tecnica in 1957 by Antonio Rubbiani. A few years later, technologists at CBS developed a procedure for a videodisk.

Videotape recording became commercialized in 1956, and it wasn't until 1964 that 3M showed a snow-plagued videodisk, nonetheless demonstrating publicly that this format had a future. The most recognized first -- generation disk recorder would be the Ampex HS -- 100, introduced in the 1967 time frame, which stored 1800 NTSC fields using analog technology and four stepper-driven recording head units that covered the surfaces of two rotating metal disks. The HS -- 100 marked the entrance for sports replay and set the standard for slow -- motion, instant replay and non-linear recovery of moving images.

The developments for recording moving images to spinning disks continued to develop in lockstep with disk drive technologies. Strongly driven by graphic arts, video recording technology for broadcast commercial applications went into full swing when Quantel introduced the Paintbox in 1981. With no D-1 tape available, digital images were offloaded onto either 8-inch floppies or the FSD removable hard drive, (from Control Data/Hitachi/NEC), then exchanged between proprietary, Quantel-like systems. The Quantel Harry, unveiled in 1986, became the first NLE that used digital technologies for multi-layering of live video. Harry remained the benchmark for television graphics (through Henry and Hal, circa 1992) and, with the 1993 introduction of the Dylan fault-tolerant drives, set the stage for RAID -- like protected video storage systems going forward -- albeit via proprietary and dedicated systems.


And it was only 20 years ago, in 1983, when the storage of computer data began its migration to the compact disc with both NV Philips and Sony showing real products for the first time in November 1985. A year later, Compact Disk-Interactive (CD-I) was announced by the same companies; followed by CD-ROM/XA (Compact Disk-Read Only Memory/Extended Architecture). In 1990, CD -- WO and CD -- MO were developed, and the age of optical storage was launched into full orbit. The laser disc would be employed first in the arcade game Dragon's Lair in 1983. It was 1997 before the first DVD-movies went on sale.

In the early 1980s, the concept of a graphics-based stillstore was born with the Ampex ESS (electronic stillstore). The first all digital NLE was introduced in 1983, as the last 2-inch quad video tape machine was shown, and one year after the first sale of original Betacam-format VTR. Abekas would soon unveil an affordable, small -- form factor disk -- based still recorder, the A42, in 1985, marking its entrée into the digital disk-recording marketplace.


From 1984 going forward, more discrete production quality moving image digital-disk recording products appeared. Products from companies such as Quantel and Abekas also brought out complimentary compositing systems. For example, Abekas produced a stand -- alone digital -- disk recorder, the A60, which recorded 25 seconds of NTSC video onto two Y/UV disk drives, and gave rise to the Abekas A62 (in composite format) and the Abekas A64 (in component digital) formats-pairs of A60 series drives linked with video mixing, layering, and graphics control processors.

It was 1989 when Avid Technology introduced and shipped the original Avid/1 Media Composer, setting off the digital-desktop editing revolution that would change video and film production forever. The non -- linear editor used proprietary motion -- JPEG imagining on a Macintosh platform, and external SCSI drives for storage.

Since the introduction of the early video-disk recording device, the television industry has functionally transformed the disk recorder from a sports replay device into a tool with extensions well beyond those first single-purpose applications. Even with the 1991 introduction of HDTV disk recording by Philips, with the HDDR-1000; it would take two or three more years before disk recording concepts would mature to the level that a professional video server could be developed and sold, e.g., one of the first Tektronix Profiles, introduced in 1995.

Today, throughout major broadcast and content-delivery centers, spinning disks are becoming the mainstay for moving image asset storage and playback. What once took 50, 24 -- inch diameter disk drives to store just 5 MB of 7 -- bit data; we now see redundant mirrored multi -- terabyte disk arrays attached to protected DVD -- RAM storage in similar footprints consuming an area about the size of the average living room. We can only wonder where the next 50 years will take us.

Karl Paulsen

Karl Paulsen is the CTO for Diversified, the global leader in media-related technologies, innovations and systems integration. Karl provides subject matter expertise and innovative visionary futures related to advanced networking and IP-technologies, workflow design and assessment, media asset management, and storage technologies. Karl is a SMPTE Life Fellow, a SBE Life Member & Certified Professional Broadcast Engineer, and the author of hundreds of articles focused on industry advances in cloud, storage, workflow, and media technologies. For over 25-years he has continually featured topics in TV Tech magazine—penning the magazine’s Storage and Media Technologies and its Cloudspotter’s Journal columns.