28

Because a closed tape loop doesn't buy you anything in random access latency, which is presumably the problem you're trying to solve. The problem is that large tape loops, like 8-track, only can wind one way. So on average, you need to wind the tape halfway through to get to a random piece of data. The worst case, you wind the entire tape. Random access ...


23

They were used, but suffered from latency issues and complex electro-mechanical design challenges. Their brief day in the sun was around the mid-1950s: after that, it was likely cheaper to add another drum or disk platter rather than work out massive tape-loop logistics. An example of a large tape-loop system was the Machine Mathématique IRSIA-FNRS (MMIF), ...


12

The back looks like a 50 Pin Centronics. I am just not sure how I can connect such a device using modern computers, if at all. Any suggestions or guidances would be much appreciated! Well, it seems to be a classic 50 Pin SCSI-1 interface - or at least compatible. So do it the same way it always has been done: Get yourself an SCSI interface card. Jup, it's ...


12

unlike with big drums or disks, you don't need to carefully align the heads on a huge surface but can just let a small part of the tape come to the fixed head. Sounds a bit like you never had to do so ;) I started my professional life in tape/disk service And believe me, there's a lot to be adjusted at a 34xx compatible tape drive head - not to mention what'...


11

Obviously, you can just switch tapes as you go, but systems that used cassette tapes for storage weren't really viable for collaborative development. Simply because with a cassette tape, you had "what's in memory" and "what's on tape", and the occasional task of saving and loading from a tape. So you could have someone walk over with a cassette so they can ...


10

Probably, no serious software development was done purely on tapes. Floppies were used extensively, as well as cross-tools, ROM emulators etc. This nice and free book, telling about the creation of the famous ZX Spectrum game named "R-Type", has also some insights into the typical development process for ZX Spectrum.


9

The standard tape reels had a capacity of 260 feet of tape. Standard tape thickness was 1.25 mil, so it would have theoretically been possible to put more tape on a reel if you made it thinner (which was hard to do because thinner tape was typically also stretchier). Making the reel larger wasn't a good option because the hubs on the drives were too close ...


8

DECtape was used that way; it was wide (0.750 inch?) magnetic tape, on very small reels, so it didn't take forever to find a sector. PDP-8 and PDP-11 systems from Digital Equipment were the likely systems sporting DECtape drives. The tape was fully redundant, took a LOT of wear without losing data, and that made it suitable for such system-program use. ...


8

Closed tape loops may not have been popular, but they were used occasionally. One of the first computers, Colossus, used a paper tape loop for read-only data storage (the ciphertext to be decoded was stored on the tape). This tape was stuck in a loop and driven at high speed (~45 km/h) past an optical reader.


8

That quote sounds quite chaotic. My experience about tapes (and disks) moved to/from storage in /370 installations is of orderly carts made to hold up to 50 tapes or 6-8 disk stacks, fine labelled and handled on a fixed schedule (twice daily, some places more often) by a dedicated service. No running with tapes up the arms or alike. Everything planned ahead -...


7

What about complex applications? You bought a floppy drive, or before that, used punch tape. The period where cassettes were the only form of storage on micros was basically zero. Up to about 1976 the ASR33 was widely used as the main I/O system for micros, and it had a punch tape system. You could also buy stand-alone punches and readers, both RS232 and ...


7

There are two ways to achieve a tape loop: Keep all of the tape perpendicular to the same plane, and add enough rollers that the tape never has to wrap against itself. This approach works well for things like tape echo units that have only a few seconds of tape, if even that much, but quickly gets bulky and unworkable for handling larger quantities. If ...


6

TL;DR Yes, there where sevelal professional mainframe (related/connected) devices that did use analogue recording. Most of them developed arround 1970 and used until the early 80s. The key reason to use them was cost reduction in a large volume installation and higher reliability. Where ever the low transfer speed and the serial nature of tapes was ...


6

In the company I worked for, there certainly weren't people "running around" with tapes etc. The "tape library" was a whole department, and the physical storage occupied almost a complete floor of the computer building. The size of the library was well over 10,000 tape reels - not all "active" or regularly used, but much of it was data from engineering ...


6

It depends a lot on the machine, the job and your team size and what time we're talking. Professional developers usually didn't work on the same minimal setup as their target user. Especially in the begining it was common to develop on a larger, somewhat compatible system (or total different with cross compilers) with 'real' mass storage, and usually better ...


5

The first thing you need to do is to open the front door of the drive and inspect the rubber roller that drives the tape. It is not uncommon for the roller on old drives to have deteriorated into a black goo. You don't want that stuff fouling your tapes. Second, you need to inspect your tapes and ensure that the belts are still good. These belts develop ...


5

The fascinating thing to me is the way in which the media is a hybrid of a punched card and a floppy. It's more like a floppy - especially in its original version, the IBM 2321 Data Cell Drive of 1964 (see below). MagCards are a downscale from the 2321, which was, at its time the top end of random accessible online storage. They provide much larger storage ...


4

Comparing the two set of bytes suggests there might have been a problem where the tape physically "stuck" and then "jumped", reading erroneous data: 10 10 00 35 D9 D9 8C 8C 45 32 6E 6E Of course there is no way to know what conditions the tape had been stored in, how well the tape reader had been maintained, and how the reading ...


3

QICStream became Backup Exec, which is still available commercially although I don’t know whether the current versions can still read QICStream tapes (I doubt it). Conner Backup Exec for DOS was capable of reading most QICStream tapes, and it can still be found online. Some data conversion companies are still capable of dealing with such tapes too.


3

If you were really determined, you could develop a program in assembly, on a tape-based micro, where the program was too large for the source to fit in memory. I did this on a TRS-80 model I with... I think 32KB of RAM. It was a long time ago, but I think that's right. The idea is to break the program up into modules, with each module having some related ...


3

There's another use of tape drives that is "sort-of" random access and floppy-like, besides DECtapes: The Exatron Stringy Floppy and the ZX Microdrive used tapes that consisted of a closed loop in a cartridge, and was used for home computers (TRS-80 resp. Sinclair ZX Spectrum) as a cheaper alternative to floppy disks. The loop was transported much faster ...


3

The VHS (and Beta) protocols required signals to mimic frames of television picture, so are hardware-supported in complex ways. Digital use (possible exception of PCM audio) was rare. The CompactCassette trademark licensing requirements precluded audio-player-incompatible use, so modified cassettes were used for digital directly, OR audio-compatible ...


3

You can use these types of tape cassettes for digital storage by acquiring the correct kind of tape drive and/or interface for each. For VHS cassettes the "tape drive" would be a standard VCR connected to a special interface card that converts digital data into analog signals that can be recorded as a video signal. These special interface cards aren't made ...


3

An erstwhile popular closed tape loop analog storage medium (8-track tape) was used to carry digital signals, although only for toy purposes: Milton Bradley's (MB) OMNI Entertainment System was an electronic quiz machine game first released in 1980, similar to Jeopardy! or later You Don't Know Jack video game series, using 8-track tapes for playback ...


3

(Credit goes to @tofro for the answer) The actual command to activate ftape is: $ sudo modprobe zftape This loads both zftape and ftape, and creates all the necessary devices under /dev, so there's no need to run MAKEDEV.


3

There is no easy answer without way more information - especially as it's a non-IBM machine. In any case, a bit flip on 9 track is of course possible, like with any media. Detecting it depends on a lot of factors not mentioned so far - for example what format is used, what block structure, if at all, and what additional checking this block structure offers. ...


2

It is very unlikely this was ever done on legacy reel-to-reel tape machines, since the time to wind through a 2,400 foot tape to find the next block of data would have been ridiculously slow. In commercial computing applications, the standard way to process a large dataset in "random order" was to start by sorting it into the required order. This could be ...


2

The 'virtual tape' (let's say .TAP files) format will strongly depend on the actual tapes you're trying to back-up. For example, Commodore (64) only cares about tape signal crossing zero, so a tape "emulator" simply emits those signals at given intervals. Markers (EOT, ECC) and others are also encoded as the same signals. This format simply determines ...


2

First, don't know anything about Minix; if it's anything like early x86 Unix/BSD/Linux it will have a Wangtek driver that Just Works (caveat: haven't tried a non-SCSI QIC drive in 20 years...YMMV). Second, there's two parts to this one for DOS: Driver - you'll need a driver for the card. This will dictate a lot about what runs. Since it's not SCSI, you'...


2

You most likely wrote your early experimental programs in the BASIC language, using Timex’s ROM-resident BASIC interpreter and line editor. Cassette-tape storage would have been accessed using the SAVE and LOAD commands in the interpreter’s immediate mode. Commercial software, however, would nearly always get written in machine language — to gain the best ...


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