The bigger 8" floppies were remarkably robust. The boot floppy for an 11/780 fitted into an LSI-11 mounted on the front door, with a vertical disk drive slot so you opened up the cab, ignored all the CPU cards, put it into a slot, closed it up and booted.
The operator I knew frequently had this folded up in his pocket: You just had to smooth it out a bit, make sure it rotated inside its kevlar sleeve, and off you went.
(DECTAPE was famously robust, everything was written out about 5 times in the tape, it was designed for light industrial deployments. It was wide like old school 16 track audio tape, not like classic 1/2" 800/1200/9600 bpi computer tapes, before DAT/DLT cartridges and the like. But that said, the old tapes were pretty robust too)
Similar story with C64 5.25” floppies. At the computer shop I worked at in 1989 we had a Microprose Soccer floopy disc without its shell, just the magnetic core. We used that to load the game and it always worked flawlessly. Sometimes we missed the floopy drive’s door, and the disc would crumple, but still work.
One piece missing from the description is the "write protect" notch in the 8" & 5 1/4" floppies. if the notch was present, the biscuit was read/write on that side. If it was not present, or was covered with a piece of tape, that side became read-only. If looking the diskette from the top, the notch would be in the upper right edge.
Early drives only wrote on one side of the diskettes. Someone discovered that diskettes had magnetic material on both side, so the diskette could be flipped and written on, doubling the storage. A notch would have to be cut to make it read/write, but it worked relatively reliably.
Later drives got second read/write heads and the flipping went away.
On the 3 1/2" diskettes this became a sliding tab. But, in their wisdom they flipped the concept. They reversed it. "missing" or open notch meant write-protect, and closed notch meant read/write.
The magnetic material on both sides had a very practical reason to be workable in all kind of floppy drives.
For example the write/read-head in a C64 floppy was placed on the bottom, so the down side of the floppy got magnetized. But the head of the floppy drive from a Atari 800 was placed at the top, so the upper side got magnetized.
So basically, when a floppy was sold as 1S (single sided) this was pure marketing. :) At least for the most floppy drives.
There's also a second thing, the "index hole". On real 2S floppy there are 2, one for each side. But most of the drives didn't care about this index hole. So, this wasn't relevant for C64 users and such.
Interesting article. I immediately thought of one (very obscure) thing I know about floppy disks which the author appears not to – "deleted sectors".
Before the data of each floppy sector, is a sector header. Among other information, it contains a flag byte, which can have two different values, indicating two different types of sectors – normal and deleted. There are different commands to read/write normal sectors vs deleted sectors. Historically, this came from the IBM 3740 data entry system, where each (128 byte) floppy disk sector stored one database record, there was not much in the way of a filesystem, and you would delete database records by changing a normal sector into a deleted one. Subsequent systems (such as IBM PC floppy controllers) retained this feature despite it being useless for their purposes. Almost no microcomputer/PC software ever used it, the principal exception being that it saw repeated (ab)use to implement an (easily circumventable) form of copy protection. Apparently, some late model PC floppy controllers (1990s / early 2000s, just before floppy drives disappeared entirely) dropped support for deleted sectors completely, viewing it as a disused legacy feature which was a waste of circuitry to support.
Well, that's true for any floppy based on the traditional IBM minicomputer/mainframe floppy format, which includes IBM PCs and many CP/M systems. It isn't true for floppy disk formats which lack that IBM heritage, for example Apple II floppies.
There were no sectors, just data fields. Also each data field had a text key field. I think IBM only gave this up (really virtualized it) when commodity hardware became better than their own.
So I'm wondering if CKD was ever a thing on floppies?
One thing that isn't covered is that 3.5" discs (and presumably 3" as well) actually do still have an index pulse, even though there's no index hole. The metal disc attached to the centre of the disc is keyed (the rectangular hole offset from the centre), so the drive generates the index pulse from the position of the spindle, rather than using an optical sensor to read the disc.
It just hit me that when I was doing IT support for some departments in college I laughed at how antiquated tape storage backups were as I saved my papers and homework on to magnetic storage 3.5" floppy drives.
A friend in high-school used to do the old trick of copying a DLL onto a floppy disk, renaming it "essay.doc", and handing it in to the teacher. Next week he'd feign concern that the disk must have got corrupted somehow, but by then he'd bought himself an extra week to write the paper.
That is funny of course (in hindsight), at least if you tried to save on 1.44MB 3.5" floppies. When I was restoring all of my old tapes and floppies I could recover nearly all my 9-track CCT tapes, nearly 100% of my 5.25" floppies (various densities, including 1.2MB), many 720KB 3.5" floppies (8" ones are also good) and zero 1.44MB 3.5" floppies. Discussed this with many other people who had basically the same experience with HD 3.5". All of these were stored in the same physical environment. Some other tape media weren't particularly good (exabyte, 4mm tape etc, but then again those used to fail at the very beginning).
> The Victor 9000 was perhaps best known for how it was able to achieve such high density on it's floppy disks. It used variable speed disk drives; there were 9 different speeds used. As the drive head moved outward the speed would increase. It was really neat to hear the speed change as the drive head moved.
I miss portable physical storage in general. USB drives aren’t the same because they are both a media and interface. I guess the spiritual successor is SD cards but I would love a cheap, not necessarily huge or super fast storage, but with excellent resilience and archival properties for 50+ year storage. That’s a niche I feel like was never filled. The debate around CD/DVD/Blu-ray and various dyes never really died so I never dared using them for that. Best recommendation for home use (because tape is more enterprise oriented) seems to be multiple hard drives and verifying them every now and then, but that always felt like such a crutch, haha.
https://retrocmp.de/ is also a great reference for particular drives. And if you need floppies, email Tom at https://www.floppydisk.com/ - he’s a top bloke and the disks I’ve got from him have all been in great working order.
The 3.5" Micro Floppy Disk was my favorite. I remember converting over 2000 files from 5.25" to 3.5" to save space at home; it took me months. Additionally, after a year and a half, I bought a 1x CD burner, which rendered my software collection obsolete within a matter of months too. Ah, those days of installing Windows 3.1 or 95 using disks, switching dozens of diskettes in the process!
The HP Itanium dev units we worked with at ActiveState in 2000 shipped with an Imation floppy drive. If I recall correctly, the install media for HPUX shipped on an Imation disk. It was a true beast.
I remember the Amiga let me customize the format with some tools. One could format more tracks than the specification to fill 900+ kB on a DD floppy beyond the initial 880 kB Amiga standard format. Gave important bragging rights when put against 720 kB PC plebs. Some games used it for copy protection i.e. copy protection on track 80+ https://eab.abime.net/showthread.php?t=101343 Of course, X-Copy and others knew and copied extra tracks.
Is there a similar post about LTO tape storage drives? I'm wondering how the newer generations achieve the insane transfer speeds and storage capacities.
There's quite a lot of similarity with how hard disks have dramatically increased their aerial bit density in that improvements in bit encoding and decoding techniques and DSP technology play quite a big part - actually LTO is behind hard disks on areal bit density as tapes have a different set of trade-offs as a removable media and archival format.
I have fond memories of 2MF 3.0 by Ciriaco García de Celis which I used to store an UC2 archive of a maximum of 2 megabyte on a single HD floppy. Booting a minimal DOS, the AUTOEXEC.BAT created a fast RAM disk D: where I extracted the UC2 contents in, a minimal windows 3.1 in d:\win - the last command was starting windows from the ram drive in the 8M machine.
I had to boot with this floppy on the library index computer as all the other text processing wordperfect 5.1 computers were taken by other students.
Windows write.exe was excellent as a wysywig wordprocessor.
https://en.wikipedia.org/wiki/2M_(DOS)
I still have some 5 1/4" floppies and I wanted to read them (if still possible at all). I still have an old drive, even an HD 1.2MB one.
However, it's literally impossible to find USB to 5 1/4" floppy interfaces now in Europe. I only found one outfit in the US that sells them, but they refused to ship to europe :(
If anyone has any tips I'd appreciate it because I'm pretty lost now.. I have much old hardware but nothing that can drive a 5 1/4" floppy drive. It's mostly unixy stuff like HP9000's and Macs.
If you’re willing to buy/be given/dumpster dive some e-waste, there are endless old-but-not-vintage PC motherboards that can be had for minimal money (like, $10-20 with CPU and RAM) that will still accept a 5.25” floppy drive and will still run a modern Windows or Linux for ease of transfer. Think Core 2 era. I have a HP Z400 workstation from ~2010 that will take a floppy drive. Beware though because some machines will be BIOS/chipset limited to only accept 3.5” 1.4MB drives. I think my HP is one of those.
EDIT: actually, no, I just looked it up — the Z400 will take a 1.2MB 5.25” drive. It will not take DD drives of any kind.
If you have the drive, you can probably bit-bang the interface pins with a Raspberry Pi or the like. There might already be something in a dusty corner of GitHub for this, or it would be a fun little project for anyone with hobbyist-level EE skills.
Just so happens I watched this on YouTube the other day. Someone is building up a board that will hook a floppy drive up to a MiSTer FPGA build so you'll be able to access it from the MiniMig Amiga emulator core. I'm always impressed by what people are doing in the retro scene these days.
This has reminded me of the awe felt by 12 year old me when someone showed me that you could use a hole punch to make a hole in the corner of a single sided 3.5" disk to double the capacity.
Adult me is now going to go look into how or why that worked.
[+] [-] ggm|2 years ago|reply
The operator I knew frequently had this folded up in his pocket: You just had to smooth it out a bit, make sure it rotated inside its kevlar sleeve, and off you went.
(DECTAPE was famously robust, everything was written out about 5 times in the tape, it was designed for light industrial deployments. It was wide like old school 16 track audio tape, not like classic 1/2" 800/1200/9600 bpi computer tapes, before DAT/DLT cartridges and the like. But that said, the old tapes were pretty robust too)
[+] [-] Someone|2 years ago|reply
That’s exaggerated, but the first 8” floppy held only about 80 kilobytes (https://www.ibm.com/ibm/history/ibm100/us/en/icons/floppy/br...), with tracks that were over half a mm wide (32 tracks/inch), and about 62 bits/mm. It also was read-only.
Reading https://archive.org/details/ibmrd2505ZE/page/n5/mode/1up, that soon become about 250kB. That’s also what DEC’s first ones stored, according to https://en.wikipedia.org/wiki/List_of_floppy_disk_formats.
[+] [-] sedatk|2 years ago|reply
[+] [-] WaitWaitWha|2 years ago|reply
Early drives only wrote on one side of the diskettes. Someone discovered that diskettes had magnetic material on both side, so the diskette could be flipped and written on, doubling the storage. A notch would have to be cut to make it read/write, but it worked relatively reliably.
Later drives got second read/write heads and the flipping went away.
On the 3 1/2" diskettes this became a sliding tab. But, in their wisdom they flipped the concept. They reversed it. "missing" or open notch meant write-protect, and closed notch meant read/write.
[+] [-] Aldipower|2 years ago|reply
For example the write/read-head in a C64 floppy was placed on the bottom, so the down side of the floppy got magnetized. But the head of the floppy drive from a Atari 800 was placed at the top, so the upper side got magnetized.
So basically, when a floppy was sold as 1S (single sided) this was pure marketing. :) At least for the most floppy drives.
There's also a second thing, the "index hole". On real 2S floppy there are 2, one for each side. But most of the drives didn't care about this index hole. So, this wasn't relevant for C64 users and such.
[+] [-] skissane|2 years ago|reply
Before the data of each floppy sector, is a sector header. Among other information, it contains a flag byte, which can have two different values, indicating two different types of sectors – normal and deleted. There are different commands to read/write normal sectors vs deleted sectors. Historically, this came from the IBM 3740 data entry system, where each (128 byte) floppy disk sector stored one database record, there was not much in the way of a filesystem, and you would delete database records by changing a normal sector into a deleted one. Subsequent systems (such as IBM PC floppy controllers) retained this feature despite it being useless for their purposes. Almost no microcomputer/PC software ever used it, the principal exception being that it saw repeated (ab)use to implement an (easily circumventable) form of copy protection. Apparently, some late model PC floppy controllers (1990s / early 2000s, just before floppy drives disappeared entirely) dropped support for deleted sectors completely, viewing it as a disused legacy feature which was a waste of circuitry to support.
Well, that's true for any floppy based on the traditional IBM minicomputer/mainframe floppy format, which includes IBM PCs and many CP/M systems. It isn't true for floppy disk formats which lack that IBM heritage, for example Apple II floppies.
[+] [-] jhallenworld|2 years ago|reply
https://en.wikipedia.org/wiki/Count_key_data
There were no sectors, just data fields. Also each data field had a text key field. I think IBM only gave this up (really virtualized it) when commodity hardware became better than their own.
So I'm wondering if CKD was ever a thing on floppies?
[+] [-] ralferoo|2 years ago|reply
[+] [-] sebazzz|2 years ago|reply
[+] [-] Yhippa|2 years ago|reply
[+] [-] fuzz_junket|2 years ago|reply
It was a different time...
[+] [-] Tor3|2 years ago|reply
[+] [-] h2odragon|2 years ago|reply
> The Victor 9000 was perhaps best known for how it was able to achieve such high density on it's floppy disks. It used variable speed disk drives; there were 9 different speeds used. As the drive head moved outward the speed would increase. It was really neat to hear the speed change as the drive head moved.
https://www.old-computers.com/museum/computer.asp?st=1&c=210
[+] [-] dtgriscom|2 years ago|reply
[+] [-] snvzz|2 years ago|reply
0. http://lclevy.free.fr/adflib/adf_info.html
1. https://github.com/keirf/greaseweazle/wiki
[+] [-] jzombie|2 years ago|reply
[+] [-] jug|2 years ago|reply
[+] [-] loopdoend|2 years ago|reply
[+] [-] cout|2 years ago|reply
[+] [-] nickt|2 years ago|reply
https://retrocmp.de/ is also a great reference for particular drives. And if you need floppies, email Tom at https://www.floppydisk.com/ - he’s a top bloke and the disks I’ve got from him have all been in great working order.
[+] [-] meerita|2 years ago|reply
[+] [-] jug|2 years ago|reply
[+] [-] ttul|2 years ago|reply
[+] [-] jug|2 years ago|reply
Another related article to this: http://www.trevormarshall.com/byte_articles/byte19.htm
[+] [-] ad-astra|2 years ago|reply
Title: “How did Microsoft store 1.68 MB on Windows 95 Setup diskettes?”
[+] [-] ChrisArchitect|2 years ago|reply
The Floppy Disk Museum on a Bootable Floppy serving from a 286 PC
https://news.ycombinator.com/item?id=34350158
[+] [-] amelius|2 years ago|reply
[+] [-] tomatocracy|2 years ago|reply
[+] [-] hypercube33|2 years ago|reply
[+] [-] fsiefken|2 years ago|reply
[+] [-] wkat4242|2 years ago|reply
However, it's literally impossible to find USB to 5 1/4" floppy interfaces now in Europe. I only found one outfit in the US that sells them, but they refused to ship to europe :(
If anyone has any tips I'd appreciate it because I'm pretty lost now.. I have much old hardware but nothing that can drive a 5 1/4" floppy drive. It's mostly unixy stuff like HP9000's and Macs.
[+] [-] bogantech|2 years ago|reply
https://github.com/keirf/greaseweazle
[+] [-] einr|2 years ago|reply
EDIT: actually, no, I just looked it up — the Z400 will take a 1.2MB 5.25” drive. It will not take DD drives of any kind.
[+] [-] gary_0|2 years ago|reply
[edit] This might be your ticket: https://github.com/keirf/greaseweazle/wiki (Someone just posted this in another comment)
[+] [-] jalapenos|2 years ago|reply
Not shipping outside the US is routine so there's many services out there catering to that.
[+] [-] MegaDeKay|2 years ago|reply
https://www.youtube.com/watch?v=_MYw0lLerBA
[+] [-] virgulino|2 years ago|reply
https://youtu.be/kCCXRerqaJI
[+] [-] Stratoscope|2 years ago|reply
https://youtu.be/e-WakfBNHD0
Along with a cool article by the inventor about how it works:
http://silent.org.pl/home/2022/06/13/the-floppotron-3-0
[+] [-] kingrolo|2 years ago|reply
Adult me is now going to go look into how or why that worked.