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Ask HN: 3.5 inch diskette read errors, would a period correct drive do better?
6 points by rietta 20 hours ago | hide | past | favorite | 5 comments
My first attempt at restoring 1991 Learning Company Spellbound for DOS for my children is dubious. Despite being stored nowhere near magnetic sources, there are read errors on the 3.5 inch floppies and Linux could not mount them. ddrescue extracted data but I have not confirmed it works. The box also have 5.25 inch disks but I do not have a reader online at the moment, that is its own project.

My technical question is this, the USB 3.5 inch drive I have is a "USB Portable Diskette Drive" that was Made in China but has no obvious sponsoring branding. If I take the time to bring back to life a more period correct system with an actual IDE floppy drive would it read the disks more accurately?

My goal is to get more of this good DOS and early Windows educational software working for my children. This particular title is meaningful because I have the actual boxes and learned on it myself all those years ago.

One option for hardware is my parent's Leading Edge WinPro 486. The case looks to be in good shape but I have not opened the case to see the condition of the capacitors yet. It has a natively mounted 3.5 and 5.25 inch drive.

 help



10 years ago I heard “you’d better read all the floppy disks you’ve got now because you won’t be able to do it later.” You might do better with better hardware, you might not. This thing can get at the raw data

https://en.wikipedia.org/wiki/KryoFlux

which might let you get most of the bits from a bad block. See

https://goughlui.com/2013/04/21/project-kryoflux-part-1-the-...

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Neat! Thank you for the info on that one. Bookmarked!

Before I spend well over $100 importing that device, I previously was thinking of brining up a 2001 era motherboard with a USB stack and can natively host the drives, but the 486 that has sat unused may be a solid option. I presumably can find a way to transfer data to a modern system over serial cable or something.

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Learning Company software has been pretty well archived at this point. To me, the easiest approach would be to hold onto the original box/packaging for sentimental purposes, and just find a copy of it on a site like the Internet Archive.

If your goal is to use it on a period-correct system, I’d go with 34/40pin adapters that lets you read flash cards, USB, etc.

A lot of my friends have kept their old 486 computers, and everything is period-correct except for the hard drive and floppy drive which have been replaced with a CF-to-IDE for the HDD and Gotek running FlashFloppy firmware for the 3.5".

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Another comment mentions a KryoFlux. A cheaper alternative is a GreaseWeasel (£30, $30). The 4.1 version even has USB-C as a connector. You will need an external power brick with a 4pin Molex connector for 5.25 drives. You can buy these standalone or they might come with a SATA/PATA/IDE Hard Drive to USB converter. Can also use an old PC power supply if you fake the power on signal.

I've had quite a lot of success, almost 100%, over quite a long time - both 5.25 and 3.5. I did use older drives intended for "desktop" machines. The drives from Japanese companies seem to be the most reliable; NEC, TEAC. The 3.5 USB Portable diskette drives are based around laptop floppy designs. You won't be able to find a direct 5.25 to USB adapter (or modify one to work) as the speeds / data rates are all wrong, so you will need something like a GreaseWeasel or old PC for those.

I've used different reading mechanisms over the years; an old PC running Linux with a real floppy chipset + custom raw reading code, custom hardware with an F82077 + Atmel + SDCard, and most recently a GreaseWeasel.

The floppies I've recovered were stored relatively well, but were mostly my and family members data - not commercial floppies. If there is any copy protection on the floppies you are trying to read you may need to capture the flux transitions. For these, I'd check archive.org to see if someone has already generated a copy.

For 5.25 floppies fingerprints and surface blemishes can be softened / removed with ISO Propyl and a Q-tip. Floppies designed for cleaning the heads of drives seem to now be very expensive / non-existent. Manually cleaning the heads of a 3.5 drive is way more difficult. I've got ideas about using Face mask / filter material to create a cleaning tool, but it is on the experiments to try list.

Even back when floppies were a thing, I found that 3.5 drives were more un-reliable between machines than 5.25 drives. I think there was more variation in head alignment and track positioning. When I've had issues, I've always been lucky in that switching the drive vendor / model made reading the floppy possible even if it took multiple attempts or was very slow.

Good luck.

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Old diskettes can be a problem especially storage that suits the white menace bacterial / fungus that can grow on the surface and cleaning can sometimes remedy but unless it's spots that can be got though the window with an ear bud, disassembly is required.

The thing I'd recommend is search of an image of the disks if they exist. Next best is an emulation eg [1] [2] which I found by way of google and yandex

[1] https://www.abandonwaredos.com/abandonware-game.php?abandonw... [2] https://archive.org/details/super-solvers-spellbound-dos-en-...

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