The story of data storage is one of ever decreasing circles. What started as holes punched into cards, then into tape, became hard disks, floppy disks, then hard shiny disks, until eventually circles are no longer involved at all. It is also the story of transitions from one medium to another as the IT industry searched for …
Re: Article has many errors
Teletype paper tape (on which I wrote my first program in 1969) was 5-bit. Astute readers will realise that 32 characters is insufficient for full alphanumerics - there was an escape character which gave access to extended symbols, including numbers. Letters were upper case only (of course).
No mention of mercury delay lines, or magnetic drum storage?
Or the white elephant of storage - using an electron cannon to etch some bits on the film?
No mention of CRT or Magnetic Core memory, but these are all primary memory, akin to RAM, rather than permanent secondary storage like disk, tape, cards, etc.
While we are on the subject of woven fabrics, holes and magnetic storage...
Let us not forget the magnetic core memory
Also Chris was not wrong in saying the RAMAC had one head per platter, it just wasn't the RAMAC 350 (pictured) but the 353
which as you can see here does have one arm per platter
Chris just needs to use the correct image, his statement is correct.
Re: While we are on the subject of woven fabrics, holes and magnetic storage...
Sorry, but the IBM 353 disk drive was not used with the RAMAC computer system: it was used with the IBM 7030 computer system. The IBM 350 Disk drive was used with the RAMAC computer system and is traditionally called the "RAMAC disk."
Playing devil's advocate for a moment, one can easily spot an unpleasant trend in all these developments. Namely, the increasing likelihood of data becoming forever lost - entombed beyond hope of rescue in the very media intended to preserve it.
Assyrian and Egyptian records can still be read today, as they were written in plain text (of the time) on openly accessible and very durable media (stone, clay, papyrus, vellum, etc.) Cards and paper tape will last a fair while, but the data encoding might pose a problem after a while. Some early mag tape archives are now unreadable, after barely 50 years, for two orthogonal reasons: the appropriate hardware no longer exists, and the encoding is lost. Of course, when I say "encoding" that stands for a whole universe of interlocked problems. All data presupposes corresponding metadata, but all too often fallible human beings make the fatal mistake of assuming that the metadata they have in mind at the moment will always be the obvious choice.
Isaac Asimov once wrote a great short story about how, after many millennia of progress, all the knowledge of the human race is locked up in a tiny repository smaller than a sugar cube. Then someone loses it...
Rosetta Stone Re: Downside
Egyptian hieroglyphs couldn't be read for centuries, and some ancient scripts are currently undecipherable. As you say, it's an encoding problem. One nice feature of older storage methods is their ability to be accessed with no more equipment than the eyeball Mk.1 (or the finger Mk.1 for Braille).
I wonder how long it will be before the only economic way of "playing" a phonographic record is to put it into your domestic 3D printer/scanner and run a conversion program on the resulting CAD file.
Re: Rosetta Stone Downside
There are laser phonograph readers. I know someone is smart enough to build one from scrap and get it up on hackaday, so there's the economical bit.
The most enduring tapes weren't paper but mylar.
I've often considered an enduring data storage medium would be holes punched in gold plates, but that has the snag that the barbarians wouldn't think of decoding the holes before they melted it down!
I wonder what data density you could get from etching bar codes using acid on granite?
Namely, the increasing likelihood of data becoming forever lost - entombed beyond hope of rescue in the very media intended to preserve it.
"Increasing likelihood" is a dubious claim, for a number of reasons.
You haven't presented any statistics on how likely a given datum (or any other data unit of your choice) is to be lost today. We're producing, and more importantly copying, information at a tremendous rate today; certainly there's a vast amount of what would have been ephemera in any other era which is being preserved for unprecedentedly long times, and is unprecedentedly easy to retrieve. Take, say, all of Twitter (please).
The article says nothing about data-loss rates over the historical period it covers, aside from generalizations about backups and the like. Nor do you. So we don't even have any evidence at hand to claim that in the computer era the likelihood of information loss is increasing.
For that matter, how is such likelihood defined? Ratio of bits lost to bits preserved, or to total number of bits generated? That's clearly methodologically unsound; we know there are many bits we don't want to preserve, so they can't be considered "lost" in any meaningful sense. Number of occasions when data retrieval fails? That's hard to normalize for historical comparison and also doesn't assign value properly to different data collections, and it doesn't account for losses we'll only discover in the future. Cost of data loss? Even if we attempt to normalize that (accounting for inflation), we run into all sorts of difficulties with historical comparisons because the relative value of information is highly context-dependent.
We don't have any way of measuring how much information has been lost from previous eras, generally speaking, because it's lost. How much of the written output of, say, Periclean Athens are we missing? We know about some of it because of references in works that are extant, but that tells us very little about what else might exist.
Every time the Reg publishes a story on storage technologies, someone raises this topic - as if it weren't widely discussed in academia and industry, as if there weren't all sorts of proposals and standards offered to address it, as if there wasn't an industry segment that exists just to address it. Yes, data loss is an important issue, and it's one that everyone who uses information technology for anything not trivial (which includes most normally-competent adults in the developed world) should be aware of. But it's not well-served by postlapsarian grumbling about the frenetic pace of modern technology, sympathetic though I might be toward that sort of GOML sentiment.
"A 1TB USB stick fits in the palm of your hand"
Great, but it costs over $3,000 in US money; not mainstream yet :)
Re: "A 1TB USB stick fits in the palm of your hand"
Still not mainstream but probably half figure again that by Xmas :)
And the size of the Hollerith card....
....is the key to its date of origin: While the original was smaller, the IBM card of the 1920's was arbitrarily set to the same size as US banknotes of the day.... which were changed in 1929 to a smaller size.
The basic hollerith card was not the only one used in computing; nor was the teletype paper tape the only one used. you also have (as briefly noted) drum storage like Fastrand and FH432, etc. and really quitely stepped over the vast array of disk drives and the changes made (similar to the changes made in card sorters with tube and wire sensors for reading).
Too bad nothing about card punches, interpreters, collators, and etc.
I know this wasn't supposed to be a history book; so thanks!
Magnetic Drum Memories!
I remember my manager getting really excited about buying magnetic drum storage in the 70's, only to be told that he couldn't have one because the computer room was on an upper floor and the building would have to be strengthened to cope with the vibration if the drum's bearings ever got unbalanced.
Re: Magnetic Drum Memories!
I worked on a power station system in the 70s that used a pair of mag drums totalling 640K. They took all morning to back up to paper tape..
"Each increase in the bit-size..."
Word size, perhaps?
Re: Bit size
I like big bits and I cannot lie
Not a student of DEC, or anything lese, aparantly
Let's see, PDP-12 was 12-bit, not 16-bit, that was the PDP-11. PDP-8 used used magnetic tape (DECTape) long before the VAX... for that matter so did the PDP-10 (36 bit) and PDP-11.
Core memory is non-volatile; I've many times turned on a PDP-11/10 and has the boot-loader still in (RAM) memory.
IBM Punch cards used all 12 rows for "data", unless it was purely numeric.
Some machines (Teletypes for instance) read paper tape mechanically, not optically.
Gave up reading after the 1st page.
((quote source = "article"))"Storage is required by a computer because its memory loses all its data when it's switched off"((/quote))
That's only if you use that newfangled semiconductor memory. Core store does not forget just because you switch it off.
Pff. Kids these days and all that, although I'll admit to being young enough to have always used machines that forget.
Re: Another error...
That "storage is required" line was foolish anyway. Nonvolatility is hardly the sole, or even primary, driver of the development of external storage. At least equally important is the problem of disparate size - stored-program computers are generally asked to process far more data, over the course of their lifetimes, than they can accommodate in their primary storage. And then there are features such as duplication, transportation, distribution, and so forth.
Codger rule, youngsters drool
Wasn't early temporary storage done with CRT tubes, glowing with a pattern of light spots?
PDP-9 word size was 18 bit, optimized to drive XY graphics with 9 bits for each coordinate.
Despite minor errors mentioned above, I enjoyed the article. Brought back memories of working at Riley's DataShare Int'l in Calgary, Alberta during the mid 70's. We had them all: punched paper tape, reel to reel tape with vacuum chambers to buffer against tape breakage and stretching, DECtape which used wide reel to reel without vacuum and practically indestructible, a single 10 MB hard drive which rotated using a horizontal axle, the size of a Boeing disk brake, and a Honeywell with two removable multi platter disk packs, which also had a punch card reader/writer. Like working at a computer museum.
Make great bookmarks and shopping lists. They also fit neatly into a shirt pocket. At Christmas time, they can be made into decorative wreaths when spray-painted gold.
Paper tape for Teletypes came in both 5-level (Baudot) and 8-level (ASCII) widths (along with some other special-purpose formats for typesetting and from other manufacturers)
Kids nowadays will never experience the joy of seeing their names spelled out in holes on tape or cards.
Many card codes
Yes, most of the punch card world used the IBM codes, but not International Computers Ltd (ICL). So I and my colleagues in the 1970s were told to use IBM card punches with sticky labels on the keys so we could punch correct cards for the ICL 1900 computer system. When we protested, management claimed that an ICL card punch cost the same as ten IBM card punches.
Mag tape file formats
Indeed they were many and various. In particular, the format of an unformatted fortran file could be more formidable than the format of a formatted fortran file. The problem was how to represent record and file structures, and every major program did that in its own way. It all made work for the working man to do.
Just remember that today one can easily hold 1Tbyte of a disk drive in the palm of their hand, and it costs less than $100.
Compare that to disk storage of the 70's when 1TByte was a dream everyone had, and it took up a room quite large. The monthly bill for power and air conditioning was more than $100 (in dollars of the day).
Times have changed. Some of us do dream in punch cards and paper tape still, and have capabilities for them as well.
Re: Storage Desnity...
Punch cards (and punch paper tape) have a common characteristic: the more information you put into them, they lighter they become. Other media that store information by increasing internal energy increase mass.
Re: Storage Desnity...
NAND flash is initialised to all FF's so the more data you put into it the lighter it gets (electrons here)
Re: Storage Desnity...
The more 1 bits you punch, but the un-punched 0 bits? However, most characters/numbers will have some bits punched.
Each line adds another card or 8 inches.
Colossus in Bletchley Park used paper tape in the 1940s and the Plessey phone exchange parts that Colossus was based on very likely used it even earlier.
I'd advise against using "cold" nand for archiving, the data does fade, especially on TLC.
Thanks Chris for the potted history. I too noticed the omission of drum-based storage, I worked with both the Sperry (or was it Univac?) FastRand and later with the DEC VAX mini which had drum storage. The FastRand was fast but as a previous poster said it weighed tons, and was slow to boot/load. An old colleague of mine, engineer on standby, always used to avoid an overnight callout by asking the ops to reload the Fastrand and call him back. That guaranteed he wouldn't have to travel until the next morning!
Stop that tape
HP mini's, I worked with in the 1970's, used 8-bit paper tape.
The reader could scan the tape at full speed and halt at a given byte by activating a magnetic clamp.
Given the kinetic energy of the moving tape and the speed of the action working on a small area the paper should be scorched.
What in stead happened was that the tape was clamped and a pair of shockwaves was send through the tape which dissipated without damaging the tape.
AFIK when the CD-ROM came out the ~650MB capacity (not writable, at that point) was way bigger than the ~20MB consumer-cost HDD of the day, but after a few years was overtaken by HDD progress.
DVDs were useful for archive for a while. At launch they were comparable to HDD size, but now 4.7GB hardly seems much at all!
And let us not forget the laser disk, not digital as such, but fantastically better then VHS at the time, and they did attempt boldly to use it as an archive store:
I missed the punched card era, but....
I did get to experience the thrill of splicing batch codes onto old paper tape runs in the early eighties (i.e. in the days when secondary schools shoved us out into industry for a couple of weeks 'work experience' to see what it was like). Fond memories, but wouldn't go back. Mind I did like the whole big computer room setups with the air-con people working in that environment got back then.
And Other Ephemera, plus a Loss Case
Cassette tape, on both Wang 720 Calculators in 1970 and Apples & ilk in the 80's. And the technologized bastard child of cassette, DEC TK50, with a 300 baud serial interface and a damn INDEX BLOCK at one end, so that you spun up, spun down, all the time, for each file read. Cold booting a VAX from that took longer than entering a boot sequence with 16 on-off toggles on a PDP-11/70.
The whole dynamic of remove-able disk packs, and the joy of spreading head crashes across your entire storage regime ("This next one just HAS to work!").
Getting a panicked call from (nameless expired aerospace vendor) who had all the engineering drawings and specifications for the space shuttle stored in DEC (sorry, too long, I'm guessing) RX20 1.4G optical platters; the very last functioning RX20 drive on the planet had just gone non-functional, could I help them read their data? Nope.
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