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View Full Version : Source for single-sided single density 5.25 disks



ppcmini
May 14th, 2017, 01:27 AM
Any company still making them?

Chuck(G)
May 14th, 2017, 05:15 AM
What's the difference between the DSDD disks, but for the label? With 8" there's a difference, but not 5.25".

SomeGuy
May 14th, 2017, 06:52 AM
Is any company still making 5.25" disks of any kind?

Double Sided Double Density 5.25" disks will always work 100% in place of single sided and/or single density disks. The same is not true, however for High Density 5.25" disks.

GeoffB17
May 14th, 2017, 02:08 PM
I'm not aware that 5.25" disks are still being made by anyone, but you do see NOS ones being offered via ebay.

I'm using normal DSDD disks as SSDD for my Amstrad PCW, which has a 5.25" drive currently as A:. The boot code expects a SS disk, so that's what it must have. The format routine for A: expects SS also, and that's what it does. Once the system is booted, then the same drive will accept a DSDD disk OK. I've not bothered cutting the disks so they can be turned over, as I've got plenty of disks. I may well want to use them as DSDD later.

I remember that way back, when disks were relatively expensive, my brother did cut an extra slot in DSDD so he could use both side in his Atari drive, which was SS. I've still got some of his disks, now prob re-formatted as DSDD.

Geoff

Chuck(G)
May 14th, 2017, 02:35 PM
Both SS and DS low-density disks have a mylar "cookie" that's coated with iron oxide on both sides. Back in the day, disks that failed verification on one side but not the other were packaged and sold as "single sided". At the time, the cost of floppies was quite high, so offering the half-bad duds made economic sense.

But that practice went the way of the 300 nsec. DRAM chip.

Oddly, vendors of RX50 floppies, for some reason did label theirs as "single-sided" long after other vendors had stopped the practice. I suppose to know which side to put the little arrow stickers on.

Similarly, you can sometimes find floppies labeled "48 tpi", "96 tpi" or "100 tpi". Pretty much meaningless; all that implies is that the disks were verified at the indicated density.

8" floppies, as I mentioned have differently-placed index apertures for SS and DS disks.

Corey986
May 14th, 2017, 02:48 PM
There is one other permutation to all of this single sided floppy talk.... Hard or Soft sectors.

If it's hard sector, then they are very hard to find NOS. Soft sector are easy, just use double sided ones that are pretty common on eBay.

hornbetw
May 14th, 2017, 06:05 PM
Athana (http://www.athana.com/index.html) still makes new floppies of all 3 sizes. Unfortunately, they don't list prices on their website.

Tom

Chuck(G)
May 14th, 2017, 06:54 PM
What's surprised me is that there don't seem to be any Chinese or Russian manufacturers--very unlike the electron tube (valve) situation.

JonB
May 15th, 2017, 02:57 AM
It's because tubes are still used in "hi-fi" applications, so there is a good sized market there with manufacturers able to charge a premium to their well heeled customers.

I doubt anyone in the world of retro computing wants to pay upwards of 30 per disk for brand new media.

KC9UDX
May 15th, 2017, 08:51 AM
I'll be surprised if there aren't Asian manufacturers, and Athana isn't buying them there.

As a group, we should inquire of their bulk pricing.