115
votes
Accepted
Why did the Apple IIe make a hideous noise if you inserted the disk upside down?
While some floppy drives have a sensor to determine when the head is at the outermost position, the Apple uses four approaches:
On startup, it blindly tries to move the head outward about 40 tracks. ...
- 34.7k
39
votes
Accepted
When did 5.25″ floppies exceed the capacity of 8″?
In practice, 5.25" drives equalled or exceeded the capacity of 8"
drives when 5.25" floppy drives started using HD media.
The Evolution of 5.25" Drive Systems
There are only two ...
- 24.6k
36
votes
Accepted
How did MS-DOS assign drive letters in the case of more than two floppy disk drives?
As you might imagine, the answer depends on the version of DOS.
The Wikipedia article on the topic matches my memories.
Before MS-DOS 5.0
Before MS-DOS 5.0, the basic assignments are as follows:
A:...
- 118k
34
votes
Accepted
Why are the magnetic floppy disk drives (FDD) heads not frictionless?
TL;DR:
"Frictionless" Floppies are called Hard Disks (*1), consisting of a hard media platter and a head in distance of the media (flying or otherwise)
Floppies are 2D tapes. While slower ...
- 213k
27
votes
Accepted
Could you manually eject a floppy quick enough to prevent data loss?
I did that all the time on the Apple II. The reason it worked was that some time was needed for the motor to spin up to the correct speed, and that the Disk II didn't really have an "eject" mechanism, ...
- 26.1k
27
votes
Did something like floppy disk jukeboxes for home computers exist in the 70s or 80s? Would that have been a feasible concept?
There was a product, called I think "Juke Box 5" designed for the Macintosh, which had a hopper on the top that could hold a IIRC about 20 floppies, and was designed to be placed in front of ...
- 34.7k
24
votes
Accepted
Is there any way today to recover/dump 2M disks?
In my experience, your best bet to read 2M/2MGUI disks is to find an old PC with a built-in floppy controller, and run either DOS (with 2M and 2MGUI) or Linux (with Mtools, which supports 2M formats) ...
- 118k
24
votes
Accepted
Absolute maximum number of nibbles on an Apple II floppy disk track?
The maximum is 8309 ($2075) nibbles for track 0. Well, according to a little experiment I did. ; - )
The Disk II uses Constant Angular Velocity standardized by Shugart at 300 RPM. The earlier 8-inch ...
- 7,438
24
votes
Accepted
How does a floppy drive identify the first and last sectors and tracks?
The track identification part is quite simple. Floppy formats are standardized so that there are specifications what is the distance between tracks (e.g. 96 tracks per inch) and what is the position ...
- 28.3k
21
votes
Accepted
Did something like floppy disk jukeboxes for home computers exist in the 70s or 80s? Would that have been a feasible concept?
Many home computers in the 1970s and 1980s had two floppy disk drives
Home computers had any number of drives from zero to 6 or 8, all depending on budget. Even rather restricted systems like a C64 ...
- 213k
20
votes
Accepted
What is this diskette drive?
Akhter was a home computer dealer, based in Harlow. The company still exists at a new address, now called Akhter Group plc (but probably not still selling BBC Micros!).
They were the largest sellers ...
- 8,031
19
votes
Accepted
Can I use all features of a Commodore 1571 external drive from a C64?
Mode Selection and Switching
By default a 1571 always boots up in 1541-mode
when detecting the first burst (C128) transfer it switches automatic into 1571-mode.
OPEN 1,8,15,"U0>M1":CLOSE ...
- 213k
19
votes
Accepted
Why did Atari floppies run at 288 RPM?
the 810 and 1050 specifically, ran at 288 RPM rather than 300. I can't imagine why this might be,
I do believe it was needed to securely store 18 sectors per track while using the WDC1771 at 1 MHz ...
- 213k
19
votes
Accepted
Is side 0 on the top or bottom of a floppy disk?
Head 0 is normally on the bottom, i.e. opposite side of the label. This is true for both 3.5" and 5.25" disks.
- 33k
19
votes
Is side 0 on the top or bottom of a floppy disk?
According to ECMA-125, a standard specifying high-density 90 mm floppies (so-called “3½ inch”), §4.14:
Side 0 is the side engaged by the spindle. Side 1 is the opposite side.
The spindle engages the ...
- 21.6k
18
votes
Did any laptop computers have a built-in 5¼-inch floppy drive?
The closest thing to a modern laptop that I'm aware of featuring an internal 5 1/4 drive is the Findex of 1979 which had a fairly complete (optionally battery-powered) CP/M computer including a hard-...
- 33k
17
votes
Did any laptop computers have a built-in 5¼-inch floppy drive?
If the definition sought after is very strictly speaking "integrated 5.25 inch floppy" and "battery powered", then I would like to enter the Kaypro II from August 1982:
Which is a ...
- 1,586
17
votes
Accepted
Did any laptop computers have a built-in 5¼-inch floppy drive?
As so often this depends on your definition of laptop - which is not an exact one either. There where many level of size and weight between a bulky schleppable like a Compaq Portable and a notebook ...
- 213k
17
votes
Accepted
DOSBox problem reading floppy boot sector using INT 0x13 on a drive mounted using MOUNT
DOSBox only allows absolute sector reads from disk images, as mounted by IMGMOUNT.
You can’t use interrupt 0x13, service 0x02 on drives mounted with MOUNT. (To understand that link, note that ...
- 118k
17
votes
Can powering on/off a 1541 damage a disk left inside?
According to the 1541 service manual, the device contains power-up and power-down write protection. On power-up, the CPU controls the power to read/write electronics so they are not turned on before ...
- 28.3k
16
votes
Could you manually eject a floppy quick enough to prevent data loss?
Theoretically, yes.
The disk needs time to spin up to speed before reading or writing can occur. While it varies between platforms and drives, it's at least a couple hundred milliseconds. That's ...
- 13.6k
16
votes
Can special tools recover data from floppy disks when Windows Explorer fails to do so?
It sounds like some blocks on the disk (particularly the ones containing directory information) are okay, but some (containing some file data) are not. This is a data recovery situation.
If you boot ...
- 16.7k
15
votes
Why did the Sharp X68000 use 5.25" drives?
Why did Sharp choose 5.25" over 3.5"?
Why something has 'not' been done will seldom get an easy answer. Often it might be a variation of 'why should they'.
When the X68000 was released in ...
- 213k
15
votes
How does MS-DOS 6 cache the DIR results?
Hard to answer without knowing what DOS (MS, DR, ...) in what configuration and on what machine - or emulation thereof - this observation has been made.
So here just a rough overview of the general ...
- 213k
15
votes
Accepted
Did RapidLok etc knock floppy drives out of alignment?
Many home computer floppy drives (some 1541 variants, and also e.g. Apple II drives) had no track zero sensor. That means the only way to get them to a known position was indeed to hammer them ...
- 26.1k
14
votes
Accepted
Connecting old Floppy Drive to modern computer
There are a number of devices which can be used to connect a floppy drive to a modern computer. Whether they are appropriate in your case depends on what you’re trying to do...
If you want to read and ...
- 118k
13
votes
Accepted
How does a HD floppy drive react to an ED disk?
It doesn’t, at least not in any particularly useful way. Because of the position of the density sensor cut-out on ED floppy disks, they’re detected as 720K floppies by HD drives. Their contents can’t ...
- 118k
13
votes
Accepted
Were single-sided floppy drives really more tolerant of rough handling?
In a double-sided drive, there are two heads which are necessarily closely spaced, facing both sides of the thin magnetic-coated disc once it is inserted. The concern would have been that the heads ...
- 16.7k
13
votes
Accepted
How are blocks stacked on a floppy or older HD
A sector is the minimum amount of data you can read from a floppy disk or harddisk. As you've drawn correctly, a sector is part of a track (on a harddisk also called cylinder, because there are many ...
- 26.1k
13
votes
Is it possible to delete a phantom floppy drive under Windows ME without additional tools?
Yes, just barely.
The basic reason why phantom floppy drives appear in Windows 9x comes down to a convergence of three factors:
Windows 9x, though it has its own native, protected-mode disk drivers, ...
- 21.6k
Only top scored, non community-wiki answers of a minimum length are eligible