Questions tagged [magnetic-tape]

For questions about magnetic tape storage formats

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26 votes
2 answers
3k views

What "spectacular to watch" algorithms were used for sorting tapes?

Python's heapq.__about__ variable contains an anecdote (François Pinard, circa 2000): [1] The disk balancing algorithms which are current, nowadays, are more annoying than clever, and this is a ...
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21 votes
2 answers
2k views

What was this mini-computer tape troubleshooting process

Back in the early 1980s I worked at a bank. My department input data into a mini-computer which was then to a mainframe system each day. I'm pretty sure it was a DEC mini, if only because the ...
0 votes
2 answers
196 views

Could visual inspection of the magnetic disk be used to detect the quality (or damages) of a floppy disk?

The magnetic floppy disk is sometimes used as an (infrared) light filter as shown on some pictures below. That led me to think about the actual magnetic disk and if inconsistencies or damaged could be ...
  • 1,321
15 votes
2 answers
3k views

Why are the magnetic floppy disk drives (FDD) heads not frictionless?

After reading this answer to the question How long can a floppy disk spin before wearing out? ... one could see thru the floppy... Not just badly worn, but the magnetic coating was outright polished ...
  • 1,321
4 votes
1 answer
247 views

What information could be recovered from visualized magnetic information?

I was wondering how the data on a floppy disk physically looks like. With data stored on a magnetic disk obviously that isn't visible. The Wikipedia article on floppy disks however shows a beautiful ...
  • 1,321
17 votes
6 answers
2k views

How does a floppy drive identify the first and last sectors and tracks?

I've recently found a more modern application "Floppy Disk Master-7"(Picture 2) (FDM) that visualized the bad sectors, tracks and clusters(Picture 1) on a floppy disk in a similar (but ...
  • 1,321
9 votes
1 answer
232 views

What is the effect of direct exposure of the magnetic disk of a floppy to ultraviolet (UV) light?

I was thinking of the mold issue of floppies and UV light (UV-C) came to mind. As ultraviolet (UV) is a form of electromagnetic radiation and floppies use a magnetic disk for storage and I vaguely ...
  • 1,321
2 votes
4 answers
459 views

Cheapest way to store and load small dataset in the 80s?

An extra, costly floppy drive would overkill when transferring a page of letter, storing game level data, or distributing a piece of BASIC program, and non built-in ones have to be paid. A tape ...
  • 2,438
4 votes
1 answer
280 views

Identifying and recovering programs from tapes

A couple of days ago, I was given some old tapes with programs written on them. However, I am having some trouble with them. I do not know what computer they were programed for. After recognising the ...
2 votes
2 answers
191 views

How plausible is this data corruption on an IBM 9-track tape?

Preamble For a while, I had a copy of a BESM-6 Pascal compiler which worked only on very simple programs, like "Hello, world", and would throw a division by 0 exception on anything more ...
  • 16.5k
5 votes
1 answer
244 views

Why does a DECtape have 576 blocks?

Information online states that a 18/36-bit DECtape holds 576 blocks. People claim it may be possible to add a few more blocks, but no more. Where does this number come from? Is there a hard limit ...
2 votes
0 answers
106 views

When and with which system or software was IBM's system of tape headers (VOLx, HDRx, ...) introduced?

Background: IBM compatible tape structure (*1) consists of a series of label blocks describing the volume and each file (Data Set). Essential the structure looks like this: VOL1..9 Volume header ...
  • 177k
4 votes
2 answers
889 views

How did IBM's "Mag Card" drive and magnetic media work?

In the 1970's IBM popularized an early word processing solution using their popular Selectric typewriter line and something called "Mag Card". This video demonstrates the system in operation. The ...
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11 votes
2 answers
844 views

Reading old QIC-80 tape using Linux with ftape

I have an old Colorado 250MB tape drive, which connects to the PC's floppy controller, that I'd like to use to read a QIC-80 cartridge. I know that very old versions of the Linux kernel used to have ...
7 votes
1 answer
497 views

Where to find QICStream software for reading old QIC-150 tape?

I'm trying to restore a backup from an old QIC-150 tape. While I'm able to read the raw data from the tape (using linux), I can't recognize the binary format of the data (the tape is not mine). There ...
4 votes
2 answers
419 views

Was sneakernet a job description?

'Sneakernet' is a colloquial term for moving data by walking back and forth with a removable digital medium such as a floppy disk or tape in your hand. In 'IBM's 360 and Early 370 Systems', page 533, ...
  • 49.8k
2 votes
1 answer
114 views

Which tape drives were the last to offer backward compatibility with QIC-150 Tape Cartridges?

I currently have some QIC-150 tape cartridges. These are the Imation DC6250 250 MB tapes. I understand that this came out in the late 1990's. I'd like to read these using a tape drive but want to find ...
12 votes
2 answers
2k views

What is the best way to connect an old Tandberg QIC tape drive using today's computers?

I currently have a ton of QIC-250MB tapes that I would like to read from (its been 30 years). I have a Tandberg TDC 3600 SCSI interfaced tape drive but I am lost how to connect it. In the past, with ...
16 votes
8 answers
2k views

Developing an application in the era of cassette tapes (audio-tapes)

My colleague and I have just had a conversation and we were wondering how the process of developing an application was done in the era of cassette tapes. Today we have HDDs, backup HDDs, FTPs, ...
19 votes
7 answers
4k views

Why were closed tape loops never a popular storage medium (or were they)?

Tape storage is, in some sense, the most successful technology across all of IT, being first used in the 1950s and AFAIK still unbeaten today in its niche. Though the success is mostly because tape ...
7 votes
2 answers
560 views

What DOS software can I test a QIC-02 tape drive with?

I got a Wangtek 5150EQ tape drive that connects to a dumb (made of a bunch of 74-series logic chips) 8-bit ISA tape controller card. The controller card has a bunch of DIP switches which I used to ...
  • 1,502
3 votes
3 answers
1k views

Using VHS/MiniDV/CompactCassette as digital data storage? [closed]

How can VHS cassettes. MiniDV cassettes. Compact audio cassettes be used as digital data storage? Can the error correction strength be adjusted?
  • 1,729
3 votes
1 answer
510 views

Using audio tape recorders on non-personal computers?

A Soviet manual (1978) for an interactive integrated development system named ПУЛЬТ (translated as "console" or "[remote] control panel") developed for the BESM-6 mainframe contains a cryptic note: ...
  • 16.5k
4 votes
2 answers
496 views

Cost of tape backup in 1980

How much did it cost in 1980 to buy a tape drive capable of backing up 5 megabytes of data? Both for the drive itself and per tape? (If that exact data is unavailable, I'd be interested in something ...
  • 49.8k
14 votes
5 answers
2k views

Magnetic tapes as a random access medium?

A two-part question: How widespread in legacy systems was the practice of using magnetic tapes as a genuinely random access medium at the OS level by pre-formatting them in a way before the first use,...
  • 16.5k
5 votes
1 answer
294 views

Magnetic tape data preservation format

What 'virtual tape' image format is most suited for data preservation i.e. can store metadata like density and media type of original tape, presence of data past EOT marker, parity/ECC bits etc.?