Do you remember these IBM Floppy Disks?

[mk553]

Does anyone remember when these floppy disks were made/sold? There's no copyright on it, but one of the labels on the side say it is for the PS/2 computer, which I'm thinking places this around 1987-1993.

I don't recall seeing these sold in stores back in the day, and find it interesting that it states it's a 2.0mb floppy, rather than emphasizing 1.44mb after formatting.

Anyway, got these on eBay, and I'm very impressed with their quality. I'm hoping someone might remember something.

Thanks in advance!

 

[krebizfan]

Got a box those back in 1987 with a purchase of a PS/2. I think the IBM focused stores like Computerland stocked them. At first, those were better quality than the other High Density disks but also much more expensive. One of the trade magazines might list who actually produced those.

 

[Chuck(G)]

2.0MB is the unformatted capacity; that is, with no gaps or address marks, the disk will hold 80*2*12,500 bytes, index-to-index. They're standard 1.44M formatted capacity. Many producers of HD floppies labeled them as 2.0MB. Where do I get 12,500 bytes, you may ask. Easy, a standard HD floppy spins at 300 RPM or 200,000 microseconds per revolution. HD datarate is 500KHz or 0.5 microsecond/bit. 200,000*0.5 = 100,000 bits or 100,000/8 = 12,500 bytes.

The selfsame floppy placed in a PC98 (Japanese NEC standard) drive holds 1.23M, as those drives spin at 360 RPM. (Do the math).

Here's the back of a box of 3M 3.5" HD disks:
[ATTACH alt="flopbox.jpg - Back of a 3M box of 3.5" HD floppies" type="full"]1205648._xfImport[/ATTACH]

 

[kc8eyt]

I've got a few boxes of those same disks labeled 1.0MB (720K DSDD). No dates on mine either. I like how each diskette comes with it's own plastic protective sleeve.

 

[mk553]

Thanks everyone, appreciate the info!

 

[lyonadmiral]

I bought quite a few of them off of eBay; both 2.0 and 1.0 capacities. I prefer the authentic IBM stuff.

 

[Chuck(G)]

Did IBM manufacture all of the 3.5" media with their name on the label? I was never able to get confirmation, so I'm guessing that the answer is "no".