3.25" diskettes

[Tony Duell]

> I can't speak for 3.25, but Amdek made (or at least packaged) 3" floppy 
> drives/disks for at the very least the Tandy Color Computer. If I'm not 
> mistaken (which entirely could be) they were 'electrically compatible' with 
> standard (read: IBMish) 5.25" drives. Also IIRC (tho this very well could 
> be wrong) Tony at least once mentioned they were available for a UK 
> machine... Beeb? Acorn? I *think* Acorn, but don't quote me on that.

There certainly were 3" drives that were electrcially compatible with 
5.25" ones. I have a couple of Hitachi drives that I use on a CoCo. They 
were not sold _for_ the CoCo in the UK, just spare drives that I plugged in.

3" drives were common on Amstrad 8 bit machines in the UK (CPC664, 
CPC6128,  PCW8256, Spectrum +3 etc). IIRC, the PSW drives at least had a 26 
pin 
interface connector, not the 34 pin one used on 5.25" drives, but the 
signals were the same, just on different pins.

Another UK machine to come with 3" drives as standard was the Tatung 
Einstein. A Z80-based machine that ran something called Xtaldos (a 
sort-of CP/M clone). There was single 3" drive as standard, a second one 
could be fitted internally, and 2 more added on an external connector. 
These drives certainly had 34 pin connectors, same pinout as 5.25" ones

The Oric disk drive was also a 3" unit. 

And yes, I've seen 3" drives sold for the BBC Micro (which was an Acorn 
machine). Not an offical Acorn product, though.

-tony