50 votes

Why were floppy disks invented after hard disks?

Floppy disks are harder to get right than hard disks. Early hard disks were enormous; the IBM 350 used fifty 24-inch platters. They were also rather fragile and cumbersome (heavy and power-hungry). To ...
Stephen Kitt's user avatar
41 votes

How did it come that SATA HDDs use ATA while SATA CD drives use SCSI as protocol?

Let’s start by addressing a few misconceptions. I have a new external Western Digital USB HDD here and I saw in Wireshark that it uses SCSI. That’s because storage over USB uses SCSI-style protocols....
Stephen Kitt's user avatar
40 votes
Accepted

Why were floppy disks invented after hard disks?

While Stephen Kitt's answer already hits the core, I believe it needs a bit more history, as direct access magnetic storage did start quite a while before the IBM 350. Drums and Disks First there were ...
Raffzahn's user avatar
  • 223k
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 ...
supercat's user avatar
  • 36.2k
26 votes

Should I use the internal or external drive for loading Amiga 500 games?

Amiga 500 1.3 machine only boots on drive 0 (DF0:) by default. There are programs that make it able to boot on DF1: but they're not really interesting because a lot of games either: have physical ...
Jean-François Fabre's user avatar
24 votes
Accepted

Were any external disk drives stacked vertically?

It seems to me that since disk drives are fundamentally horizontal devices that want to be wide rather than tall, To me they are taller than wide. After all, that's as well the orientation IBM did ...
Raffzahn's user avatar
  • 223k
23 votes
Accepted

How did Commodore drives produce program listings from disk directories?

TL;DR: The computer, or rather its OS, has no idea about a directory, in fact not even what constructs a file. It can only open/read/write/close data streams from devices on the bus. Getting a ...
Raffzahn's user avatar
  • 223k
21 votes

How did programs/patches stopping Amiga idle floppy drive noise work?

The sound came from the fact that drives would only report on the presence of a disk if the heads were moved. Thus by default, the OS would move the heads back and forth. Alternatively, the heads ...
nsandersen's user avatar
  • 1,753
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 ...
Raffzahn's user avatar
  • 223k
19 votes
Accepted

Any difference between a VIC-1541 and a C64-1541?

Functionally there is no difference between the VIC-1541 and 1541. Internally, there may be lots of differences due to production variation and component variation. The thing to remember is that ...
Payton Byrd's user avatar
  • 1,053
19 votes
Accepted

Default (as opposed to physical) read/write heads - what are they?

The physical geometry how many heads the drive actually has is not the same as the logical geometry of how many heads is presented to the PC by the drive. By translating the geometry, the drive can be ...
Justme's user avatar
  • 32.1k
18 votes
Accepted

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

As far as I'm aware there is no source of new 8" drives. If you do manage to find a working drive, there are a couple of options to connect it to a modern PC over USB: the KryoFlux floppy controller,...
Stephen Kitt's user avatar
18 votes
Accepted

What systems used hard sectored floppy disks?

Hard sectored 8" and 5-1/4" floppy disks were used in some early computers including: DEC Pro 350 Heath/Zenith H-89a MITS Altair 8800BT NorthStar Horizon Vector Graphic computers Processor Technology ...
18 votes
Accepted

What's the timeline of Commodore diskette drives?

You can get a relative ordering by looking at DOS versions for the drives. IEEE-488 drives 2040 - first drive, 5.25"x2@170K, 1979, DOS 1.0 3040 - 5.25"x2@170k in Europe, 1979, DOS 1.2 4040 -...
user3486184's user avatar
18 votes
Accepted

Why was the 1541 so slow?

the drive could end up only being able to transfer one bit per horizontal blank = 63 microseconds. 1/(63e-6) = 15873 bits/s = 1984 bytes/s. That would be the bitrate during transmission within a byte,...
Raffzahn's user avatar
  • 223k
18 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.
tofro's user avatar
  • 35k
18 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 ...
user3840170's user avatar
  • 23.1k
17 votes

Were any external disk drives stacked vertically?

Yes; this was standard procedure for at least the BBC Micro: Including for third-party drives: Presumably because two drives arranged that way were only just taller than the machine itself:
Tommy's user avatar
  • 36.9k
16 votes
Accepted

How can a computer use the drive's momentum for emergency power?

Any real attempt to use the momentum of the spinning disk to generate power would cause the disk to come to a halt very quickly. In essence, this is the principle behing regenerative braking of ...
Chenmunka's user avatar
  • 8,141
15 votes
Accepted

Why did the Atari 8-bit computers make beeping noises while accessing the disk and cassette drives?

The beep comes from the OS ROM, and it is actually derived from the timing of the start and stop bits of each byte shifted into POKEY, this is determined from the interaction of the interrupts ...
Thomas Cherryhomes's user avatar
14 votes

How did programs/patches stopping Amiga idle floppy drive noise work?

Since at least Kickstart 2.0, the OS has built-in code that allows for drive checking without making the click noise. To enable it, just set the TDPB_NOCLICK flag in the tdu_PubFlags of trackdisk....
user180940's user avatar
  • 3,716
14 votes

How can I access an old pre-IDE disk?

That Conner CP-343 drive appears to be a special snowflake, but it's not. It's actually a standard IDE drive, with one exception. That 20-pin interface you're looking at isn't the IDE connector; it'...
mnem's user avatar
  • 4,537
14 votes
Accepted

Bootable floppies lock up with floppy drive connected via USB adapter

In the first phase of the boot process, the BIOS loads the first sector of the disk into memory and executes it. The code in this sector then uses the BIOS to load the code for the second phase, which ...
dirkt's user avatar
  • 27.3k
14 votes
Accepted

Only "Drive A:" detected with two floppy disk drives

Unfortunately, you can't connect two floppy drives to the motherboard header on that system. Like most motherboards since sometime around 2002–2003, it only supports one floppy drive, probably because ...
Stephen Kitt's user avatar
13 votes

Obscure uses of the Commodore 8050/1541 disk drive

There were a number of programs that used the 6502 in the 1541 as a coprocessor. An obvious application was for calculating fractals, because that doesn't need a lot of RAM. An example is the ...
dirkt's user avatar
  • 27.3k
13 votes

Obscure uses of the Commodore 8050/1541 disk drive

And now this: disk drive outputs the video signal through the serial bus connector! "Freespin" Demo by Matthias Kramm (Quiss/Reflex): https://www.youtube.com/watch?v=zprSxCMlECA Technical ...
szulat's user avatar
  • 270
13 votes

How do you send code to a Commodore disk drive and run it?

How exactly does one send a new routine to the drive and execute it? Usually by executing the Memory-Write command twice followed by UserN command, as described in chapter 8 of the floppy manual (*1)....
Raffzahn's user avatar
  • 223k
12 votes

Obscure uses of the Commodore 8050/1541 disk drive

Playing music with the drive heads, of course. I've tried that too, wrecking the drive in the process. Dimming the drive LED, by flashing it very fast, with a variable duty cycle. Printing a file on ...
followed Monica to Codidact's user avatar

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