Questions tagged [floppy-disk]

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

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9
votes
1answer
3k views

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 ...
14
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2answers
3k views

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 ...
4
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1answer
197 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 ...
17
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5answers
2k views

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 ...
2
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2answers
194 views

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 ...
1
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2answers
206 views

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 ...
9
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1answer
184 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 ...
5
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1answer
470 views

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 ...
26
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3answers
4k views

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 ...
4
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1answer
205 views

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 ...
6
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1answer
236 views

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 ...
11
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1answer
2k views

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?
5
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1answer
244 views

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 ...
1
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1answer
439 views

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 ...
19
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2answers
1k views

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. ...
2
votes
1answer
206 views

"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 ...
37
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8answers
8k views

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 ...
7
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1answer
1k views

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 ...
12
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2answers
689 views

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?
1
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2answers
220 views

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 ...
3
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2answers
257 views

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 ...
25
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5answers
11k views

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 ...
3
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2answers
160 views

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 ...
2
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3answers
369 views

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 ...
1
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1answer
149 views

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?
10
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3answers
699 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 ...
8
votes
3answers
530 views

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 ...
7
votes
1answer
235 views

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 ...
10
votes
1answer
771 views

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?
-1
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3answers
301 views

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 ...
7
votes
1answer
289 views

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 ...
6
votes
1answer
310 views

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....
4
votes
1answer
168 views

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 ...
4
votes
2answers
295 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 ...
13
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4answers
2k views

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 ...
4
votes
0answers
140 views

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 ...
1
vote
1answer
115 views

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 ...
4
votes
1answer
185 views

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 ...
10
votes
1answer
460 views

Understanding the DMK disk image file format used by TRS-80 emulators

DMK is a low-level disk image file format used by TRS-80 Model I & Model III, Tandy Color Computer, Dragon 32 & 64, and MSX emulators. It's capable of representing copy-protected disks and all ...
3
votes
0answers
33 views

On the TRS-80 models I and III when is the directory track number written in the third byte of sector zero, and when in the second byte?

Earlier I had found that many but not all TRS-80 Model I and Model III disks begin with the three bytes 00h FEh 11h. This is the beginning of the boot sector where the CPU interpets it as a NOP ...
7
votes
2answers
1k views

Could Tandy TRS-80 Color Computers boot from disk at all?

I'm trying to find out if any of the Tandy CoCos could boot from disk. I'm thinking the answer is no but I'm having trouble confirming it. I believe that non-disk machines booted from the standard ...
4
votes
2answers
389 views

Can I still save data on a floppy that lost its magnetic charge over time

I have original Microsoft floppies, unfortunately they appear unreadable. Were stored in protector, in a box, in a dark and dry place for the last 20 years. No dust, moisture or exposure to magnetic ...
6
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3answers
3k views

What are D64, T64, D71 and D81 files?

The docs for the Ultimate-II+ expansion cartridge for the Commodore 64 state: It is able to read D64 files, as well as D71 and D81 files (no partitions), T64 files. So what are D64, T64, D71 and D81 ...
3
votes
1answer
180 views

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 ...
11
votes
1answer
150 views

In TRS-80 parlance when talking about disks, what are "granules" and "lumps"?

In my reading to try to learn about the disk layout, directory, and boot process of TRS-80 Model I and Model III, I see some unusual words come up again and again. Along with the common terms "track" ...
3
votes
1answer
270 views

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 ...
3
votes
1answer
130 views

What is the layout of the directory track on a TRS-80 Model I/Model III disk?

I've decided to add support for some more classic Z80 computers I used to use to my Ghidra modules, and the first Z80 systems I used were the TRS-80 model I and model III. I've found documentation ...
3
votes
2answers
132 views

Is there a "most correct" name for the disk format / filesystem used by Amstrads and Spectrum +3's?

The native floppy disk format/layout or "filesystem" used by Amstrad microcomputers such as the CPC and PCW range and by the Sinclair Spectrum +3 are versions of one that came from CP/M. In Amstrad ...
3
votes
1answer
177 views

Where can this "boot.B" file be coming from on this Spectrum TR-DOS disk image?

After working on some tools that parse the TR-DOS disk image format .TRD files for a while I just noticed that one of the game disk images I had downloaded "La Abadia Del Crimen", only has three files ...
3
votes
1answer
923 views

Problem reading 720KB floppy disks containing dat [closed]

I am using a USB connected "Sabrent FD-05PUB" 3.5" floppy drive to read data using Windows 10 computer. It shows in Device Manager as "TEAC USB UF000x USB Device" The 1.44MB disks read just fine. All ...