Questions tagged [floppy-disk]

Use, restoration and imaging of floppy disks; low-level formats of floppy media. Consider [file-system] for high-level formatting.

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Can a floppy disk be formatted in another size for (read-only) backwards compatibility? [duplicate]

Is it possible to format a 3.5″ floppy disk in another size? For example an original 1440 KiB floppy as a 720 KiB or 360 KiB disk thats (at least read-only) compatible with 720 KiB or 360 KiB drives? ...
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Are the ACTUAL DISKETTES different for 360KB Single, or Double sided? 1.2M? [duplicate]

I have lots of old IBM 5.25" diskettes. I have 360 kB "Single sided", 360KB "Double Sided" and 1.2 MB diskette drives. Are the diskettes THEMSELVES different for use in these ...
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Can you use 5.25 HD floppy disks in a DD drive?

Is is possible to format and use 5.25 high density disks in a double density drive?
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What was the last 5.25-inch floppy disk drive manufactured?

Assuming that no manufacturer of removable-media disk-drives is still manufacturing disk-drives for 5¼-inch floppy disks - what was the last drive model manufactured / sold and who was the ...
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26 votes
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Which software was the first to use copy protection?

While researching early magnetic storage around 1980, I've come to ponder if we know of the first piece of software on removable media that employed copy protection? The Wikipedia article mentions ...
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Confused about FM encoding

I'm finding what appear to be two different descriptions of how FM encoding on early floppies worked. In this description (see page 2 if it didn't go there directly) it appears that FM is nothing more ...
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9 votes
2 answers
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I get I/O errors when writing a disk image to a new old-stock floppy in a USB drive. How can I resolve this?

I wish to create a bootable DOS 3.3 installation floppy disk (3.5″, 1.44MB, 2HD, Sony branded) for my AST Premium Exec 386SX/20 laptop. I have bought a new USB floppy disk drive and connected it to an ...
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6 votes
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Were commercial Amiga floppy disks shipped with write protection?

In this Amiga "quick kickstart guide" magazine thing that I have from when I bought an Amiga 1200 long ago (it seems to be printed in late 1995), they really go out of their way to point out ...
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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 ...
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3 votes
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What do abnormal sounds or vibrations of a spinning floppy disk inside a floppy drive mean?

I saw this floppy drive sound emulator and this floppy disk sound video and wondered if the sound of a floppy drive or more specifically a the sound of a floppy disk spinning in the drive, could tell ...
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Approximately how many 3.5-inch floppy disks have been produced before manufacturing was stopped? [closed]

3.5-inch floppy disks are not produced anymore, with I think Sony being the last to stop manufacturing in March 2011. Meaning that all floppy disks that exist are currently in circulation and the ...
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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 ...
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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 ...
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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 ...
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How to determine the required RPM for a 3.5-inch floppy disk?

In addition to my other related question Is it possible to read floppy disks at non-standard rotation speeds (RPM)?. How to determine the required RPM for a 3.5-inch floppy disk as disks can ...
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Is it possible to read floppy disks at non-standard rotation speeds (RPM)?

According to this article 3.5-inch floppies rotate 300-600 times per minute (RPM). It is possible to overclock the RPM and will that result in higher transfer speeds? Or is it possible to read a disk ...
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9 votes
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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 ...
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Can powering on/off a 1541 damage a disk left inside?

The User's Guide for the Commodore 1541 disk drive includes a vague warning, on page 7, to "remember to always remove the diskette before the drive is turned off or on". Some third-party ...
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Copy content between floppy disks on Apple II

I own an Apple IIe with the Apple DuoDisk device. I've been trying to find out if it is possible to copy content from a floppy disk inserted into the disk 1 slot into a floppy inserted on the disk 2 ...
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26 votes
3 answers
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When did 5.25″ floppies exceed the capacity of 8″?

When 5.25″ floppies were introduced, in the mid-to-late seventies, they would have had less capacity than the older 8″ because, well, less area on which to store data. On the other hand, being cheaper ...
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4 votes
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How to repair IIgs 3.5 floppy drive?

The Apple 3.5" Drive on my IIgs still reads disks, but eject no longer works. The failure to eject is silent, no errors, noise, or motion. With a paperclip I can get the disks ejected but this is ...
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6 votes
1 answer
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Commodore 1581 crashes during format

I have a Commodore 1581 (800k 3.5" DD) floppy drive which reads and writes data just fine (with DD disks only of course), but it crashes (drive keeps spinning forever, stops moving the head and ...
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What is the (standardized) weight of a 3.5 inch floppy disk?

What is the weight of a 3.5 inch floppy disk and was the weight ever standardized?
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How did games written for tape-based BBC micro, get officially and unofficially ported to disk, bearing in mind extra workspace needed by DFS ROM?

If I recall, PAGE = &E00 for a BBC Model B system with cassette tape based storage. On installation of Acorn DFS ROM (with 8271 Floppy disc controller), the ROM allocated more memory, increasing ...
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How to write Apple IIgs .po disk images to Floppy Disks with an older Mac

I recently acquired an Apple IIgs with two 3.5" floppy drives and no hard disk. I'm very seasoned with older Macs, but I have no experience within the Apple II world. I search for a way to create ...
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19 votes
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How did the Apple IIGS automatically slow 5.25 inch disk I/O code for backwards compatability?

Apple II software often used hard-coded timing for 5.25 inch floppy disk I/O, for example to control the duration of each track step or the rate at which bytes are written and read from the disk. ...
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2 votes
1 answer
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"Restoring" a 1986 Compaq Portable II (Cabling question)

I am in possession of a working 1986 Compaq Portable II. However, I couldn't find a 5.25" floppy with the proper version of DOS on it to actually make the computer, ya know, work. I've since ...
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37 votes
8 answers
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How long can a floppy disk spin for before wearing out?

I'm mainly interested in 3.5" floppies here, as they're what I have lying around, but other sizes could also be interesting to hear about if anyone has the data. As I understand it, the head rubs ...
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7 votes
1 answer
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I can't read DS 1MB floppy disks

Using an USB external floppy drive, I've been able to use my Mac to back up files from a big box of 3.5 inch floppies (800K, HD 1.4MB). But I cannot even read my DS 1MB floppies using either the ...
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8 votes
3 answers
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Reading data of floppies from a ZX Spectrum Swift Disc

Back in the day when we had a Sixword Ltd. Swift Disc floppy-drive we were ahead of the game on our speccy, allowing us to use 3.5inch floppy disks. See: https://www.worthpoint.com/worthopedia/swift-...
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12 votes
2 answers
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How did 512 Bytes come to be the most common sector size?

It was long assumed by FS drivers that all diskette and harddisk units operate in blocks of size 512 Bytes. How did this happen to be the case, historically? Why not the "neater" 1 KiB, say?
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AST Laptop With No OS

I work in network design/IT for a church, and a someone came in with a AST Advantage Explorer 486SX/33. It looks like it has no OS. After failing to boot, it requests to go to the BIOS to look for an ...
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3 votes
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Did any 5.25" floppy drives not based on the Apple Disk II offer quarter-track control

Unlike many drives, the Apple Disk II has inputs that control the individual head stepper coils. These are commonly described as advancing by half-tracks, since advancing a full track requires ...
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25 votes
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Twist in floppy disk cable - hack or intended design?

There are many documents (e.g. this) describing the twist on two-drive floppy disk cable on IBM PC compatibles. While this is not the most proud example of clean hardware design, how much of this was ...
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3 votes
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How can I format a higher capacity 3 inch disc on a regular CPC6128?

A standard Amstrad 3 inch disc can be formatted to CP/M Data format on the machine: single sided, single track, 40 tracks, 9 sectors/track, 512-byte sectors, no reserved tracks, 1k blocks, 2 directory ...
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2 votes
3 answers
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First time using an Amstrad CPC 6128 Disc Drive [duplicate]

I recently got my first Amstrad CPC and started refurbishing it. Now I wonder, I saw a video, on someone using the RPM test tool for the Amstrad. I found the download online, but this question might ...
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1 vote
1 answer
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How to flash CDTV extended ROM using development board

I have a CDTV ROM development board, and I know it is possible to flash it using floppies. How to make such floppy with a custom rom?
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10 votes
3 answers
765 views

How can I boot or extract files from an IBM PS/1 with a DoubleSpace-compressed hard drive?

I’m trying to boot an old IBM PS/1, mostly with the intention to read out its hard disk. I realized quickly that the original floppy disk drive was broken, so I replaced it with a Gotek floppy ...
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8 votes
3 answers
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How to transfer AT&T 6300 ".360" disk images onto physical floppies

I got these MS-DOS 3.3 disk images for the AT&T 6300 from archive.org: ATDOS331.360 ATDOS332.360 ATDOS333.360 ATDOS334.360 Supposing that I have access to a physical 5.25″ floppy drive running ...
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7 votes
1 answer
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Could a double-sided Commodore disk be written to be used as a "flippy" on a 1541, without requiring flipping on a 1571?

Although the 1571 is capable of reading and writing both sides of a disk, accesses to the second side using the second head will be performed with the drive spinning in opposite direction from how it ...
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10 votes
1 answer
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Is it possible to boot C64/C128 from floppy

When powered on 1541 reads the disk for a brief moment. Is it used to boot system from floppy? Is it possible to create a bootable commodore 64 floppy?
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3 answers
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I need to find a controller card for an apple II 5.25 inch floppy drive, the 20 pin connector wont work on the 34 pin controller card i have

I cant find any adapters or secondary connectors, can anybody get me a link to a working floppy controller card that works or possibly a connector that goes from 20 pin male to 34 pin female? i have ...
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7 votes
1 answer
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What floppy disk format and layout and what disk image format are used for the Coleco Adam?

I just found out that emulators for the Coleco Adam use a disk image file format with the DSK file extension. This is a very very overused extension on many different disk formats. Though a few DSK ...
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7 votes
1 answer
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Did OSes write the floppy's logical sector number resulting from sector interleave/skew in the IDAM sector ID, or was it up to the OS?

I've been looking at MicroBee floppy disk image files. They use the DSK/EDSK image file format originally created for Amstrad CPC emulators, probably because both systems use derivatives of the CP/M 2....
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5 votes
1 answer
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At which RAM address is the Microbee disk boot sector loaded and executed?

The Microbee was an early '80s Z80 microcomputer from Australia that was successful mostly in education. Looking at some disk image files I've downloaded I can see the disk layout seems to be very ...
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4 votes
2 answers
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Why does Amiga 500 reset when reading a faulty disk

I have a copy of Syndicate disks for Amiga (I have original as well) and apparently the disk is damaged / faulty. It loads up to language selection menu, then tries to read disk and resets the ...
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13 votes
4 answers
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Can special tools recover data from floppy disks when Windows Explorer fails to do so?

I have many 1.44MB floppies 20 years old or older. My FDD, which I just bought online and received recently, cannot read them. The FDD can often display the contents of a floppy, but not successfully ...
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4 votes
0 answers
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What does a "DK" signature mean at the start of track 0 sector 3 of a Dragon 32/64 floppy disk?

I'm looking at disk image files for the Dragon 32 / Dragon 64 computers. The Dragon computers are very similar to the Tandy TRS-80 Color Computer "CoCo" but are not clones and are not the ...
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1 vote
1 answer
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How many different standard boot sectors are there for Apple II DOS 3.3?

When formatting a blank 5¼ disk on an 8-bit Apple II using the INIT command, was there only ever one variation of the boot sector code that was written, or was it updated from time to time over the ...
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4 votes
1 answer
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Determining which sectors in an Apple II floppy disk/image are used when the boot sector declares more than 1 sectors

The Apple II disk bootstrap process looks at the first byte of track zero sector zero to see how many sectors long the bootstrap code will be. It then loads these sectors at location 0x0800 and jumps ...
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