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Questions tagged [floppy-disk]

For questions related to the use, restoration and imaging of floppy disks.

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16answers
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Does “Disk Operating System” imply that there was a “non-disk” Operating System?

In the 1980's at primary school we saw MS DOS and DR DOS competing before Windows 3.1 and subsequent releases took over that space. At home we had Apple II's which booted up to a BASIC prompt. On ...
47
votes
20answers
12k views

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 ...
42
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8answers
9k views

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 ...
41
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9answers
16k views

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 ...
39
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2answers
5k views

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 ...
33
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8answers
9k views

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 ...
32
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3answers
4k views

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 ...
29
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6answers
1k views

Dumping and archiving C64 disks

Doing spring cleaning with family, I found some old C64 disks. These are really old and no one knows what to do with them. Archiving or dumping them seems to be options but we are unsure how to do so ...
28
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11answers
10k views

Dealing with oversized files decades ago? Data transfer in the age of floppy disks

I can imagine the following situation 20 to 40 years ago inside a working office between two colleagues: "Can I have a copy?" "Sure, wait a moment....done! [eject] I'll pass that floppy disk onto ...
27
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1answer
1k views

How does “bit-slip” copy protection work?

Some Apple II 5.25" floppies used a special pattern of bytes that could not be automatically detected by disk copying software. How could the pattern be invisible to disk copiers but detectable by ...
25
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3answers
4k views

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 ...
25
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4answers
7k views

Can I image Amiga Floppy Disks on a Modern computer?

Is there any way of reading Amiga floppy disks to 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 ...
24
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3answers
946 views

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 / ...
24
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2answers
2k views

How did MS-DOS assign drive letters in the case of more than two floppy disk drives?

The IBM PC BIOS had provisions for up to four floppy disk drives, by virtue of returning the number of floppy disk drives in a two-bit field plus a none/some flag (allowing for reporting values of 0, ...
23
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2answers
2k views

Why did connecting the IBM PC 3.5" FDD backwards cause the problems it did?

When the 3.5" FDD was introduced for the IBM PC and compatibles (or possibly earlier), someone made a decision to make the data cable between the controller and drive unkeyed. This, of course, meant ...
23
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2answers
4k 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 ...
23
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4answers
2k views

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 ...
22
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2answers
1k views

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 ...
21
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5answers
5k views

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 ...
19
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6answers
6k views

Why was the shrinking from 8″ made only to 5.25″ and not smaller (4″ or less)?

Answers and comments to Why were 5.25" floppy drives cheaper than 8"? suggest some reasons why floppy disks moved from 8" to 5.25"; basically it seems the smaller size reduced engineering ...
18
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7answers
3k views

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 ...
18
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4answers
3k views

Wanted: 5.25 floppy to usb adapter

I have found inexpensive (~$15) 3.5in floppy to USB adapter cables but have been unable to find a similar adapter for 5.25 floppy drives. Does anybody make such a thing? Are the pinouts of a 3.5 the ...
18
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1answer
3k views

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 ...
17
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2answers
2k views

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 ...
16
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4answers
4k views

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 ...
15
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3answers
1k views

What were practical uses of SCSI floppy drives?

I've always been fascinated by the rarity and elitism of such devices. However, from a practical standpoint, I don't understand why such low transfer rate device ended up in a bus commonly used for ...
15
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1answer
2k views

Is it possible to adapt a standard PC floppy drive to work in an IBM PS/2?

I have three different IBM PS/2 machines and all of them are in perfect working order—except for the floppy drives. None of the floppy drives will read disks, which means all I can do is key in BASIC ...
13
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4answers
5k views

Where can I find an external 8-inch floppy disk drive?

Where can I find an external 8-inch floppy disk drive? I have some data I would like to retrieve from a really old 8-inch (200 mm) floppy disk, but have no working computer than has a drive to read ...
12
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5answers
2k views

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 ...
12
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7answers
1k views

How to at least partially read damaged sectors of floppy disk?

It is necessary, that the floppy drive, just like CD-ROM, attempts achieving 100% data integrity using the help of error correction. If a sector is not readable, it just does not get sent to the ...
12
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4answers
5k views

Installing Windows 95 by floppy?

Ok so 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 ...
12
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3answers
2k views

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?
12
votes
1answer
364 views

What did Microsoft customize on Windows 95 installation floppy disks?

I have a Windows 95 Upgrade 3.5" DMF installation disk set where several disks were infected by the boot sector virus known as "Chance.A". I'm interested in restoring these to their original contents. ...
11
votes
8answers
2k views

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, ...
11
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3answers
2k views

Only “Drive A:” detected with two floppy disk drives

I am trying to repurpose an old Acer Aspire M1641 to copy/format bulks of 3.5'' floppy disks. I think it's one of the last generations of computers to have a 34 pin floppy disk drive header as it also ...
11
votes
3answers
779 views

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 ...
11
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2answers
308 views

What happens when a floppy track contains multiple sync words?

This question is specifically aimed to the Amiga hardware. Let's assume a floppy track is read via DMA using sync word to trigger the start. Let's also assume the track contains the sync word ...
11
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3answers
483 views

Building a floppy disk workstation to handle bulks

I need to handle bulks of floppy disks where I have to archive their contents and then recycle them by formatting them for use on old Amiga/Atari/MS-DOS computers. I currently have a 3.5" floppy disk ...
11
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1answer
717 views

Using a 360k (DD 5.25") floppy with Windows XP?

My PC XT clone went up in smoke (literally) the other day. I salvaged the half height 5.25" double density floppy drive though and dropped it into an old 1.8 ghz AMD tower I had laying around. Plan ...
10
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2answers
1k views

Which Apple floppy drive is compatible on both Apple IIc and Macintosh

I have an old Apple IIc (not Plus) and an old Macintosh Plus (1MB RAM). I want to buy an external 3.5 inch floppy drive that works on both machines, that way I don't need two different drives around ...
10
votes
4answers
713 views

Looking for an easy to use Commodore 64 disk/sector editor

First, let me say I understand that 'recommendation style' questions can be very subjective, but I believe there is enough value in a few good beginner resource pointers that others could benefit from ...
10
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2answers
574 views

Bootable floppies lock up with floppy drive connected via USB adapter

I am currently trying to mount a 3.5'' floppy disk drive in a modern computer. What I did is that I bought a 34-pin floppy drive connector to external USB adapter so that I can connect it to my ...
10
votes
2answers
700 views

Replacing the Floppy drives in my Amiga 3000

My Amiga 3000 is starting to show its age, and recently one of the two internall floppy disk drives appears to have given up the ghost... I'd like to replace the drive but the A3000 case doesn't have ...
10
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2answers
171 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 ...
9
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4answers
656 views

Is my opened floppy disk useless now?

I was wondering if floppy disks are ruined if, say, a terror of a 3 year old rips them apart... I had important pictures on a floppy disk. I was doing some spring cleaning and came across it and ...
9
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2answers
1k views

Why is the RDY signal on floppy disk drives disabled?

While look at some 3.5" floppy disk drives I have, I noticed they have a little resistor missing next to RDY and, looking it up online, I find some instructions for adding a resistor there to enable ...
9
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2answers
259 views

Disk drive long storage, with or without disk inside?

I am asking myself what is the best when storing a 3.5 disk drive for a long time but still planning to use it in the future, what is the best: Store it with a disk inserted, or leave it empts ?
9
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3answers
452 views

How can I copy software which is too large for one Atari ST floppy disk?

I have downloaded the STOS game creator from the STOS download page. I'm trying to copy the software from my computer to a floppy disk formatted on an Atari ST, but I get an error message saying the ...
9
votes
2answers
686 views

Transferring files between Commodore PET and IBM PC

Suppose you have two early eighties computers, a Commodore PET with 8050 disk drive and an IBM PC with its 5.25" disk drive. Is there a way to transfer files between them? Not machine code programs, ...
9
votes
1answer
427 views

HxC floppy emulator on Amiga 1200, second virtual drive disappears after reboot

I've recently purchased a HxC/Lotharek SD Card floppy drive emulator. It's working well replacing DF0: but I'm seeing some odd behaviour with its emulation of DF1:. On the first boot after power-up, ...