Questions tagged [floppy-disk]

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

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9
votes
2answers
595 views

How can I read a 5-1/4 drive on 1996-2007 equipment?

In my organization's archive I just found some 5-1/4" floppies, presumably IBM PC 320/360k. They contain information that we have on paper, but I'd really like to have on electronic media, not least ...
2
votes
1answer
80 views

What are the differences between the various HxC Floppy Emulator hardware options when used with an Apple II?

I have an Apple IIc for which I would like an FDD emulator and I am considering buying an HxC Floppy Emulator to use with it. The Slim model does work with the Apple II, as demonstrated in this video. ...
23
votes
8answers
5k views

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 5 1/4" disks. I assume it managed it by destroying some redundancy like a ...
6
votes
2answers
210 views

Are there any open-source C64 DOS wedges and fast loaders?

The ever-so-popular EPYX Fast Load cartridge for the Commodore 64 included a DOS wedge (adding commands such as $ to list the files on a disk, /filename to load a file and @ to show the disk error ...
55
votes
3answers
17k views

What is the “two-drive trick” that can read Amiga disks on a PC?

Standard belief is that the floppy disk controllers used on PCs are incapable of reading Amiga floppy disks, due to the PC disk controller expecting a very specific low-level format of disks, whilst ...
7
votes
2answers
144 views

What are the most common Apple II disk image formats and what hardware disk drive emulators can use them?

Archive.org has plenty of Apple II disk images, such as this DOS 3.3 image which is a .dsk file. I also see .nib and .d13 files, e.g. in this ASIMOV LISP collection. There seem to be further formats ...
12
votes
0answers
317 views

Oxford C compiler for Commodore 64

I kept one floppy from my Commodore 128 (which I used mostly in C64 mode), which is written Oxford C compiler. It is a 5.25" floppy. Don't ask me why I kept just this one; probably because I thought I ...
11
votes
4answers
3k views

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 ...
23
votes
4answers
4k views

Can my floppy disk still work without a shutter spring?

One of my floppy disks' shutter spring got lost. Now the shutter can't slide normally. Can I still use the floppy disk?
6
votes
1answer
395 views

How-to destroy sensitive data on floppies?

What was considered the best practice, or "military-grade" procedure, for protecting secrets stored on floppy disks when disposing of the old disks?
6
votes
2answers
392 views

Is there a program I can run on the C64 to speed up booting of a game?

Though I had several friends back in the day with a Commodore 64, I only recently acquired one after a friend gave me his old one before he moved house. As such, I'm diving in to learning about the ...
6
votes
7answers
3k views

Were any external disk drives stacked vertically?

There was a time when floppy disk drives were big, expensive devices that in many cases, instead of being components of a computer, would be separate machines connected by a cable, in some cases with ...
9
votes
5answers
692 views

Drilling 720Kb floppies to 'upgrade' them to 1440Kb?

I remember back then, there were few people that used to drill an extra hole on them to double their capacity. Surprisingly, it worked! While the other way around is plausible I am quite unsure of ...
22
votes
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 ...
25
votes
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 ...
4
votes
3answers
514 views

Gotek drives for MS-DOS (plus few more constraints)

I have installed two gotek device instead of two old unworking floppy disk drives (in particular on an Olivetti PCS 86). And the result is something like this: (The one on the right should the the A:...
18
votes
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 ...
19
votes
3answers
5k 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 ...
4
votes
3answers
277 views

What was the DOS FAT12 720k floppy raw disk format structure?

I am looking for detailed info on the low-level floppy disk structure of an MSDOS-compatible 720k Double Sided Double Density disk. Stuff like GAP/SYNC patterns, ID and CRC Field structure, standard ...
8
votes
4answers
732 views

Amiga floppy disks and GCR vs MFM

According to https://en.wikipedia.org/wiki/Group_coded_recording the Commodore 1541 disk drive used a particularly efficient GCR encoding scheme to cram 170K onto the same 5.25" disks that in an Apple ...
19
votes
7answers
4k 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 ...
2
votes
1answer
352 views

How to read old 3.5" Macintosh formatted floppies on a MacBookPro

I have connected a USB external floppy drive to my Macbook Pro (OSX El Capitan). I am unable to "view" the external drive, and hence unable to access the floppy content. I have inserted a floppy, ...
16
votes
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 ...
4
votes
2answers
540 views

Can a Harlequin ZX Spectrum clone be modifed to run CP/M?

The ZX Spectrum (and therefore the Harlequin) has its ROM from $0000 to $3FFF, while RAM further up to $5AFF is used for the screen (see Memory-Map). As CP/M expects RAM from $0000 upwards the two are ...
5
votes
2answers
258 views

Tools for creating disk images on Mac Plus

I got BMOW's floppy emulator and have been pulling a bunch of files from 30 year old floppies (which have a miraculously low rate of failure) onto my SD card. One of the things I wanted to copy was a ...
9
votes
4answers
2k views

Purpose of two disk drives on the Osborne 1

I recently discovered the Osborne 1 computer, and I noticed it had two floppy disc drives. What was the purpose of including two drives?
13
votes
1answer
634 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. ...
6
votes
1answer
836 views

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 ...
4
votes
2answers
943 views

How can I use ImageDisk (.IMD) images with VirtualBox, WinImage, etc.?

I've got ImageDisk installed on my old 486, and I've been ripping some disks for archival purposes (some 3.5", some 5.25"). It spits out .IMD files, which contain some amount of header and metadata, ...
3
votes
2answers
98 views

FDD data dropouts after changing disks

I'm building a FDD controller out of a $10 microcontroller. It's mostly working pretty well, and I can read both 720kB and 1440kB PC MFM disks (the only ones I have to test with). However... if I ...
9
votes
1answer
1k views

Weak bits on floppy for copy protection

How did the vendors using copy protection create weak bits on the floppies? This always fascinated me as a kid. I ended up finding a weak bit emulator that would intercept the floppy disk interrupt ...
11
votes
3answers
1k 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 ...
48
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 ...
6
votes
1answer
1k views

Copying disk images to Commodore 64 floppy disks

For some time now I have been on a mission to get back into playing games on a Commodore 64. I have bought an original Commodore 64C. I got hold of a original 1541 disk drive. I also got hold of a ...
35
votes
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 ...
4
votes
1answer
312 views

Which DOS for a TRS-80 Model 4P?

Looking at the TRS-80 Disk Software Page, there's a rather extensive selection of DOS options that seem to work with the 4P and also claim high compatibility with the Tandy "TRSDOS" option. ...
2
votes
2answers
949 views

Commodore Amiga 600 Software Failure. “Error: 8000 0004 Task: 000026D0”

Software Failure on Commodore Amiga 600 when I insert a floppy in drive. Software Failure. Press left mouse button to continue. Error: 8000 0004 Task: 000026D0 Independent from the floppy I ...
3
votes
1answer
263 views

Using floppy disk interface on Future Domain TMC-1680 SCSI ISA card

I have this old card, a Future Domain TMC-1680 ISA SCSI card that has a 34-pin floppy disk connector on it. I am trying to research that to see if I can make it work (before anyone asks - just for the ...
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, ...
8
votes
4answers
1k views

Were external floppy drives for Atari ST and Amiga inter-compatible?

Were external floppy drives for Atari ST and Amiga inter-compatible? For example, Commodore 1541* had its own serial bus protocol. But what about the external 3.5" DD floppy disk drive on 23pins D-...
8
votes
3answers
1k views

How to spin up 1541 drive without C64

I have a 1541 drive and I want to make it spin but I don’t have a Commodore computer. I don’t need to read data, I would just like the drive to spin. Can I manually tell it to spin using a raspberry ...
13
votes
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 ...
9
votes
4answers
860 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 ...
8
votes
2answers
270 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 ?
3
votes
1answer
178 views

My floppy drive in my IBM model 8525-001 doesn't seem to be working

I tried to put a floppy disk into my IBM model number "8525-001" and it doesn't seem to be processing it. The light below the floppy drive blinks yellow every once in a while (such as when I turn ...
6
votes
1answer
1k views

Availability of 5.25" floppy emulators?

Emulators from Gotek or HxC support 3.5" floppies. However none seem to support 5.25" PC drives. Are there any alternatives out there?
5
votes
3answers
2k views

Recovering old Commodore 5.25" floppy disks

I picked up a Commodore 64 with about 1,500 floppy disks. Many of them are de-magnetised and there is currently only one disk I can run (been through about 100, I can see the files of 2 or 3 disks, ...
6
votes
3answers
504 views

Commodore VIC-20/64/128/16/Plus 4 floppy disk drive replacement

We all know that floppy disks are getting hard to find, and floppy drives are fragile to begin with (especially Commodore's 1541 drive). I know that several companies and parties have released floppy ...
13
votes
10answers
6k 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'...
13
votes
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 ...