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49

For the simple reason that until relatively recently, it was very difficult to make a rewritable optical medium, but it was easy to make a rewritable magnetic medium. Magnetic tape as a recording medium has been a practical technology since the late 1930s, predating the digital computer. For comparison, CD-RW was introduced only in 1997, more than a decade ...


35

As far as I remember, this wasn't a CD, but (supposed to be) a Laserdisc, and he was using a Philips player (the movie contained several Philips machines). Laserdiscs were available in different sizes between 12 cm, which is like a CD and up to 30 cm (LP size). In a technical way, the movie screwed up, as Laserdisks were neither digital (they used an ...


26

Write speed and endurance. Optical drive technology has been much slower to write to than magnetic Hard Disk Drives (HDDs). The erasable optical technologies that made it to mass market were much slower in write time than HDDs and in erase time. Their life before failure was in the 100's of erases. Optical drive use declined with the advent of USB flash ...


18

The Datassette has a digital interface, and since it is not meant to process audio signals at all, it allows directly writing sharp digital magnetic transitions to the tape, using a single monophonic read/write head. The written pulses are always written at same amplitude, so there is no variation between equipment. Also when reading the transitions off the ...


15

That is a Philips VP415 LV-ROM player.


10

What prevented optical drives from being used as the dominant secondary storage like the magnetic disk drives in PCs? Speed Density Complexity Technological advantage of Disks Reliability Did I mention speed and density? Even a Blue Ray does only pack 25 GiB of data on a (5.25) side. Actual HD do up to 700 GiB per (3.5) side. At times various ways of ...


5

I don't think so, and I don't recall reading or hearing about any such data storage technology, although mechanical data storage (in its broadest sense) might have been done using Bakelite. For example, cam-actuated "programmers" that control electrical equipment may may have used Bakelite cams, and this could be considered to be a form of data ...


4

and less susceptible to damage from dust and vibrations because of the absence of microscopically closely placed read-write heads That, exactly that (in reverse) made magnetic storage to integrate the media with the r/w heads and later their controller, enclose them in a dust-proof box and call the whole thing "hard disk". Optical media, being read and ...


3

The datassette doesn't have the bias circuit on recording, because on digital data wasn't necessary, and also has sensors that informed if the motor was engaged. Also the power supply was from the computer so no batteries or extra plugs were involved. On the reproducing part a circuit designed to process a digital signal doesn't introduces unnecessary stages ...


3

I believe the datasette had the ADC built in, so it could then transmit digital signals to the computer. By optimising for digital output, the unit should have been more reliable, compared to a conventional tape player which would have bias settings for a more accurate output of analogue sound data.


3

Light isn't small enough. Let's compare a couple of numbers for the present day: Wikipedia: The magnetic surface of each platter is divided into small sub-micrometer-sized magnetic regions, each of which is used to represent a single binary unit of information. A typical magnetic region on a hard-disk platter (as of 2006) is about 200–250 nanometers wide ...


2

They were, at one time. Admittedly, optical tape drives rather than disc, which had several advantages : removable media for one. Here's one : part of Colossus but I have used them in the 1970s and early 1980s where they were sometimes used to interchange data between computers and EPROM programmers.


2

I found this question because I was getting the same symptoms on my Tandy Model 100 when trying to load a text file that I had just (seemingly successfully) recorded to an MP3 file on a Zoom H1 recorder - the TEXT program would just sit there and wouldn't respond to anything, even turning the unit off and on didn't help and I had to reset it (didn't lose any ...


2

The 'every third bit' consideration arises from the mode in which one instruction can read three tape lines. The bits from the tape end up 'interleaved' in the AC. I suppose the single shift between characters requires less electronics (or time?) than a 6-bit shift would do. See for example the description of 'read in mode' in this memo. Admittedly this ...


1

There are three ways an attempt to load a tape can fail: The loader reports success, but the data is incorrect. The loader reports failure and does not read correct data. The loader reports failure, but in fact loads the data correctly anyhow. Commodore's tape system does a very good job of preventing failure #1. Unfortunately, it writes two complete ...


1

And people did use vinyl grammophone records to store computer programs (though more as a gimmick), see for example here about a Commodore 64 program hidden within Prodigal’s 1984 album entitled Electric Eye. There also was the Flexi-disc, a thin square of plastic with a program on it, which could be produced very cheap, and came as part of a computer ...


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