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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What modification is required from a PC floppy for use in Amiga?

Around the end of the time of Amiga popularity, obtaining a replacement Amiga floppy drive was a nuisance, while PC drives were ubiquitous and cheap. One could install a PC drive in Amiga after ...
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How long will floppy disks maintain data integrity?

This was on CNN today: The U.S. is still using floppy disks to run its nuclear program Which led me to read through this article: Think the floppy disk is dead? Think again! Here’s why it still ...
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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?
Matthew's user avatar
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Finding byte boundaries in floppy disk MFM bitstreams

I'm building myself a floppy disk interface based on a microcontroller. I'm successfully reading the bitstream off the disk and (probably) decoding the MFM bitstream into actual bits, based on the ...
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42 votes
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What is between the sectors of floppy disks?

I've found this page which has an informative description of how sectors were encoded on floppy disks: http://nerdlypleasures.blogspot.com.au/2015/11/ibm-pc-floppy-disks-deeper-look-at-disk.html Do ...
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Windows 95 installation floppy images are larger than 1440 KiB. How can I fit their contents on standard floppies?

I have an old laptop with only a floppy drive. It came with Windows 95 on it but suffered from some terrible BSoDs that I could not resolve. I figured I would just download some Windows 95 install ...
Mark's user avatar
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2 answers
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When did the floppy disk icon become the standard symbol for the “save” function in user interfaces?

The floppy disk icon is a widely recognized symbol in user interfaces, typically representing the “save” function. Screenshot depicting a floppy disk as "save" icon When did the floppy disk ...
Avalon Sinclair's user avatar
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8 answers
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Why were floppy disks invented after hard disks?

For those of us who grew up with personal computers in the 1970's or 1980's, the experience was a very gradual migration from floppy disks to hard disks as the primary persistent storage. So, based on ...
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Magnetic exposure to floppy disk damages file system and requires complete reformat?

What I noticed is, that formatting a floppy disk takes three times as much time for the same data amount as writing a file to the disk normally. The accoustically perceivable jumps of the head between ...
neverMind9's user avatar
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26 votes
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Cleaning 5¼" floppy drives

Going to the store is treacherous for me. So I prefer doing stuff at home, including cleaning up 5¼" floppy disks with only home supplies. Unfortunately, I do not know how or which materials/chemicals ...
Anthony Pham's user avatar
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Why did 3.5" floppies win (and not another size)?

It's an open question whether desktops would've kept using 5.25" until the end of the floppy era, but laptops meant something smaller was going to be introduced; that much was essentially ...
rwallace's user avatar
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Adding the third floppy drive?

I've seen a few computers with more than two floppy drives, most with two 3.5" and one 5.25". My question is how was this achieved? I've heard that it could be done with a second controller card, but ...
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Writting DSK images onto a 3″ floppy for Amstrad/Sinclair computers

For a project I'm working on, I need to write some disks to test on my Amstrad CPC 6128. I've got some 3″ blank disks, and all my Amstrad computers (CPC and PCW) have 3″ disks, as well as my Spectrum +...
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Was there a special drive, that saved much more than 1.44MB on an HD floppy disk?

I think that I have once seen an Internet article, which stated, that special drives are capable of making many megabytes of data out of one ordinary MF-2HD floppy disk. But I am unable to find it ...
neverMind9's user avatar
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Can the Gotek floppy emulator be made to work with classic Macs?

The Gotek floppy emulators are really popular in the retro scene. I have one modified (firmware update) to work with my Amiga 500. Can one be made to work with any of the classic line of Macintosh ...
cbmeeks's user avatar
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Converting Apple II ProDOS blocks to DOS tracks and sectors

The 8-bit Apple II had two disk operating systems with different disk access semantics. DOS used tracks and sectors. A sector is 256 bytes. ProDOS used blocks. A block is 512 bytes. But mapping ...
hippietrail's user avatar
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Why were floppy drives not any faster?

180rpm to 360 rpm, unlike 12000rpm on optical discs, was how fast floppy disks got. I am not sure, whether all drives had the same speed, but 360rpm is not close to the physical stress limitations of ...
neverMind9's user avatar
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20 answers
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Did personal computers ever support 8" floppies?

When I look at the following picture, it seems a bit awkward to me that personal computers ever supported 8" floppies (unless the size of your computer case was as big as a fridge !): Am I right or ...
Eric Cartman's user avatar
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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 ...
spacer GIF's user avatar
31 votes
6 answers
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Can I image Amiga floppy disks on a modern computer?

Is there any way of reading Amiga floppy disks to a PC hard drive? Can I use a standard floppy drive with a firmware program that will translate it? Do I need an external drive or a working Amiga ...
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What were the differences in floppy disk formats between Amiga and IBM/PC compatible computers?

The capacity in Amiga Old File System format (OFS, OS version 1.x) was 840KB, with the Fast File System ("FFS" (!)) introduced for OS 2.x onwards able to store 880KB. The PC format stored 720KB on the ...
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30 votes
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Absolute maximum number of nibbles on an Apple II floppy disk track?

The Apple 2's disk drive controller and 5¼" floppy disks have the following metrics: The disks is spun at (roughly) 300 RPM (Revolutions per Minute), which means it takes = 1000 ms/sec / (300 RPM / ...
Michaelangel007's user avatar
27 votes
9 answers
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What other tricks were there to get more data onto floppy disks?

I remember using a utility back in MS-DOS 3.3 days, called MAXI Disk, that somehow magically managed to get 420K on a 360K 5¼″ disk. I assume it managed it by destroying some redundancy like a backup ...
user230910's user avatar
27 votes
2 answers
5k views

Why were 5.25″ floppy drives cheaper than 8″?

The first floppy disks were eight inches. This size was set by IBM; I haven't been able to find any indication of why they chose it, but maybe it was just because it seemed quite small to them ...
rwallace's user avatar
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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 ...
rwallace's user avatar
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What makes a floppy disk bootable?

A lot of web sites describe how to create a bootable floppy disk using an existing image (via dd). But what about the image makes it bootable? I'm interested in making my own bootable floppy images ...
Sydius's user avatar
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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 ...
tuomas's user avatar
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Why not constant linear velocity floppies?

The outer tracks of a disk are longer than the inner tracks, and could therefore potentially hold more data. Constant angular velocity puts the same number of bits on every track, which wastes much of ...
rwallace's user avatar
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21 votes
9 answers
19k views

Formatting a 720K floppy disk over USB fails with Windows 10

I've read many times that USB floppy drives will not format (or read/write) 720K disks. But then I read several posts online where people say they have done it. Even with Windows 10 (which is what I'...
cbmeeks's user avatar
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21 votes
2 answers
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Is there a better way to the 6 disks install of Windows 3.1

I want to install Windows 3.1 on my MS-DOS 6.22 Machine. I have the 6 disk images. But I only have 1 or 2 spare Floppy disk that I can write the disk images onto. One way I can think of is to write ...
Tom Shen's user avatar
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19 votes
1 answer
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Did 5.25" floppies undergo a change in magnetic coating?

3.5" floppy disks, in the transition from 720K to 1.44M, changed the actual coating to a different compound that was magnetically 'stiffer'. This was necessary to support the higher density, but meant ...
rwallace's user avatar
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16 votes
4 answers
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Is there any way today to recover/dump 2M disks?

2M disks where formatted using 2MGUI to increase 3"1/2 & 5"1/4 DD/HD/ED disks' capacity. Is there any way today to recover/dump these disks to a file with modern hardware? Specially the 5"1/4 ...
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15 votes
8 answers
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Why did common floppies never advance past 1.4 MB in size?

The chronology of some early floppy standards was: 80 kB, 160 kB, 360 kB, 720 kB, 1.2 MB, finally 1.44 MB. (There were less common sizes such as 250 kB, 800 kB, ...
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13 votes
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Writing 800k Mac floppy images for 1.44M-equipped Macs using Linux

If you have Macintosh filesystem image of an 800k boot disk, but your physical Mac has a 1.44M SuperDrive, how can you produce a physical disk that can boot that Mac?
knghtbrd's user avatar
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9 votes
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What is the VTOC format for an AppleDOS disk with more than 50 tracks?

I am trying to read files of an AppleDOS 3.3 disk. The documentation I've found, both from Inside AppleDOS and also from Archiveteams' website (which I believe was taken from Inside AppleDOS): http://...
David Given's user avatar
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9 votes
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751 views

How can I tell if an Apple II disk image is bootable?

I have around 500 floppy disk images from an Apple II and IIgs BBS/usergroup that closed down recently. Some of the disks are bootable, but many aren't. Is there an easy way to tell if a disk boots ...
scruss's user avatar
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9 votes
2 answers
298 views

Apple II: ProDOS partitions on floppy disks?

On the Apple II using ProDOS, was it possible to create partitions on a floppy disk? Would it be possible to have two or more partitions on a 140k 5.25" or 800k 3.5" disk? (The question here is not ...
Dale Mahalko's user avatar
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9 votes
1 answer
381 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 ...
Bob Ortiz's user avatar
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7 votes
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522 views

Why does _Beneath Apple DOS_ show FM encoding rather than GCR?

From the beginning in 1978 the Apple II floppy disk system used GCR encoding to convert data bytes to sequences of binary values to be written to the diskette: first 4-and-4 encoding (never released), ...
cjs's user avatar
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7 votes
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How could a 16-sector PROM Apple II access a 13-sector disk?

When the Disk ][ first came out for the Apple II, the PROMs on the interface card only knew how to work with a 13-sector format. Around 1980, the Disk ][ was updated with 16-sector PROMs either for ...
bjb's user avatar
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7 votes
1 answer
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How to install System 7.5.5 on a Macintosh SE/30 using floppies?

I have a Macintosh SE/30 with a formatted Disk. I'd like to install the latest System 7 on it that will run. According to Wikipedia that should be 7.5.5. According to several sources Apple has made it ...
Andreas Hartmann's user avatar
7 votes
1 answer
1k views

DD vs HD vs ED floppy disks: lifespan/writecycle difference? Other differences?

DD, HD and ED floppy disks have individual materials to match their densities. But is density their only difference? Are there any differences regarding: Maximum allowable rotation speed? Rewrite ...
neverMind9's user avatar
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5 votes
3 answers
500 views

How do I know where the file directory is stored on a Spectrum +3 disk layout?

I'm trying to parse Spectrum +3 disk images. I only ever had a tape-based Speccy back in the day. The +3 had a built-in floppy drive but was late to the party and not that successful. It had the same ...
hippietrail's user avatar
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5 votes
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How does the Spectrum +3 know whether a disk is bootable or not?

I've been looking through documentation on The Sinclair/Amstrad Spectrum +3 which was the only Spectrum that came with a built-in floppy disk drive. The disk format was based on The Amstrad CPC and ...
hippietrail's user avatar
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Is there anything useful for a retro in these cheap Chinese floppy drives?

Looking on eBay for floppy drives, I came across these incredibly cheap Chinese 3.5" USB drives (there are lots of them on offer). https://www.ebay.com/itm/USB-1-1-2-0-Portable-External-3-5-1-44MB-...
tofro's user avatar
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4 votes
1 answer
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What is the process for TRS-80 Model I & III to boot from disk?

I can find enough mentions of bootable disks for TRS-80 Model I and Model III to be confident that they could boot from disk, but so far I'm failing to find much info on how that worked. In ...
hippietrail's user avatar
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4 votes
1 answer
331 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 ...
Bob Ortiz's user avatar
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4 votes
2 answers
421 views

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 ...
Bartek Malysz's user avatar
3 votes
2 answers
967 views

What file formats were used for binary executable files on later Sinclair ZX Spectrums?

The last official version of the Sinclair ZX Spectrum was the +3, released after the company was owned by Amstrad. It included a 3-inch floppy disk drive as used on other Amstrad computers. But even ...
hippietrail's user avatar
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2 votes
1 answer
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What systems used hard sectored floppy disks?

Which computer systems used hard sector indexing of floppy disks? Background: On 5 1/4" and 8" disks there is a hole punched into the disk used for optical timing to locate the start of sectors. ...
Dale Mahalko's user avatar
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