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Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

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Old 14th Jan 2013, 3:38 pm   #1
Stuart R
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Default 5.25 & 3.5 inch diskettes -any use still?

Hello,

I'm trying to have a tidy at home and have tripped over another box of computer floppy discs, manuals and CDs. This reminded me that I have a pile of similar bits growing in the loft -including an IBM PS/2 with external 5.25" drive. Not sure really why I am keeping them!

Are 5.25 and 3.5 inch floppy discs of any use to collectors or are there so many about still that I should just send them down the tip? Have around 40 5.25" 3M DS DD "diskettes", some still sealed in boxes and a similar amount of 3.5", probably half of them used.

There are also a few Magazine cover discs (mainly useless demos) and DOS 4, boxed with manuals -all 5.25".

This isn't an "Items Offered" post, so don't place any 'orders' here. I would create a more detailed list in the correct section if people think that they should be steered away from landfill.

Regards,

SR
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Old 14th Jan 2013, 3:45 pm   #2
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Are the 3½" discs 1.4M (HD) or 720K (DD)? The 1.4M ones have a second hole on the opposite side from the write-protection hole.
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Old 14th Jan 2013, 4:06 pm   #3
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Hello Dave, Pretty much all the 3.5" are HD as they have the second hole. I did buy a pack of WHSmith 720K DD ones and some of those are floating about. There are some Maxells (MF2HD) promising 2MB.

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Old 14th Jan 2013, 7:06 pm   #4
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Yes, these disks are worth keeping or offering. There are still people (like me) using them and looking for blank ones. DD (as opposed to HD) are particularly difficult, being older and less numerous.

Chris
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Old 14th Jan 2013, 10:46 pm   #5
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

In my early days we had 8" floppies... yes 8" with hard sectors determined by holes punched near the hub as well as soft sectored with just one index hole per rotation. 125KB was storage for single sided disks then!!
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Old 14th Jan 2013, 11:17 pm   #6
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

I must confess that I too am old enough to remember 8" floppies. DEC RX01 perhaps? I think they were soft sectored.
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Old 14th Jan 2013, 11:54 pm   #7
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Both 3.5 and 5.25 low density are useful for collectors especially for Commodore 64 and Amiga use. Definatley don't take them to the tip!!!
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Old 15th Jan 2013, 12:11 pm   #8
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

For the sake of anyone who has never seen an 8" disc (and for the rest of us to wallow in nostalgia), here is one of mine. I notice, however, that even the soft-sectored discs were a lot less standardised than the 5¼" ones - having just looked at one of my Cromemco 8" discs, I notice that the index hole is positioned differently.
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Old 15th Jan 2013, 2:26 pm   #9
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

The beauty of 8" and 5-1/4" floppies was that you could drive you office chair over them and, even though wrinkled, they'd still work perfectly! I never had a dead 5-1/4" but threw endless 3-1/2" floppies away which failed.

Yes they are collectable.
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Old 16th Jan 2013, 3:57 am   #10
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Circa 1990 I found what was, according to its printed lable, a single-sided 3 1/2" disk in one of the scrap bins at the Marconi Research Centre where I was then working. I think it was made by SONY. The only visible difference from a 720k disk was that the sliding cover would latch in the open position, requiring you to squeeze the corner of the casing to release it to cover the magnetic surface. Both sides of the disk were visible when the cover was slid open. It wouldn't read or format either in a Windows 98PC or an Amstrad PCW 3 1/2" drive. I have never come across any references to single-sided 3 1/2" disks.
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Old 16th Jan 2013, 7:16 am   #11
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Early Apple Macs and Atari STs could use single sided 3.5in disks. Double sided soon became the standard, though.
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Old 16th Jan 2013, 1:37 pm   #12
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

I am not quite old enough to have used 8" discs but I do remember 5.25" ones.

Circa 2000 NASA were said to be trawling eBay and similar sites for 8" discs and drives as the space shuttle used them!

For the record the HD 3.5" floppies are still quite easy to obtain, my local WH Smiths still has them on sale. The 720K discs are harder but it's quite possible to use a 1.4Mb disc in a drive designed for 720K...also many early Atari ST users utilised double sided discs in a single sided drive...it merely read and wrote to one side only.
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Old 16th Jan 2013, 1:47 pm   #13
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

I was in the floppy drive business in 1980s and a lot of the US made 8" drives were very unstable and needed regular realignment. My company sold Mitsubishi 8" and 5 1/4" well engineered drives that went on for ever without being touched.
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Old 16th Jan 2013, 2:17 pm   #14
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

We still use eight-inch floppies to carry our HF broadcast schedule. There have been occasional drive problems, but we haven't had one for years.

Attached is a pic of part of our BBC D&ED Automatic Control System, incorporating dual 8" drives.
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Old 16th Jan 2013, 5:58 pm   #15
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

From memory the index hole on the 8inch floppies indicated whether it was high or low density, there were certainly two different locations.

Robin
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Old 16th Jan 2013, 9:18 pm   #16
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Quote:
Originally Posted by Gulliver View Post
The 720K discs are harder but it's quite possible to use a 1.4Mb disc in a drive designed for 720K.
Do you actually have experience of doing this? I ask because I have never been able to make a 720K drive access or format a 1.4M disc, even with the second hole covered up. Presumably, however, the hole would only be detected by a 1.4M drive and is irrelevant to a 720K one.
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Old 16th Jan 2013, 9:31 pm   #17
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Looking more carefully at one of my Cromemco discs, I see that it does, in fact, have two index holes. The one in the same place as the one I displayed earlier being covered up by a sticker.

Judging by the legend on the sticker, it would appear that the different positions indicate whether the disc is single- or double-sided.
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Old 16th Jan 2013, 9:52 pm   #18
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

I have formatted 1.44M disks to 720k in the external 720k 3 1/2" drive I fitted to my Amstrad PCW8256. While it usually worked, formtting and writing took a long time as it sounded as if the drive was repetitively going back for another go to complete the operation. The respective magnetic coatings of 720k and 1.44M disks have different coercivities. I haven't tried to format a 1.44M to 720K using a 1.44 M drive.
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Old 16th Jan 2013, 10:17 pm   #19
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

I once upon a time drilled the second hole in some 720K discs and formatted them to 1.44 meg without any trouble.
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Old 16th Jan 2013, 10:31 pm   #20
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Default Re: 5.25 & 3.5 inch diskettes -any use still?

Quote:
Originally Posted by emeritus View Post
The respective magnetic coatings of 720k and 1.44M disks have different coercivities
As I understand it, 720k and 1.44M 3.5" discs actually have similar coercivities but the coating on 1.44M discs is about half the thickness of that on 720k discs. That's why formatting 1.44M discs to 720k using a 720k drive is often successful but struggles a bit - I believe the signal read back from the disc is simply weaker, so the drive has problems recovering the data reliably.

In contrast, 360k and 1.2M 5.25" discs have very different coercivities, so 1.2M discs are completely hopeless in non-HD drives.

Chris
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