Windows 95 almost had floppy insertion detection but the training cost was prohibitive

  • Thread starter Thread starter Franc Zabkar
  • Start date Start date
Is this a late April Fool's joke?

Windows 95 almost had floppy insertion detection but the training cost
was prohibitive (posted April 02, 2009 7:00 AM):
http://blogs.msdn.com/oldnewthing/archive/2009/04/02/9528175.aspx
http://tech.slashdot.org/article.pl?sid=09/04/04/1717242&from=rss

AFAICT, all you need to do is to look for an active DISKCHANGE signal.
A single STEP signal, presumably toward TRACK0, will clear it.

- Franc Zabkar
Click to expand...

That's interesting. I had always assumed that apple's had smarter floppy
hardware, heh.

I think this post from /. user Jamie's Nightmare sums it up well:




You're a bit out of focus here. It worked well on the Mac and the Amiga
because the floppy drives themselves were different. The hardware was
designed to signal the machine when a disk was inserted via a
switch/sensor inside the drive that was depressed when the disk was
inserted. Similar, but in a different location than the "write protect"
and "high density" sensors. This method is simple and it works. The only
real point of failure is the possibility of the switch going bad, but I
can't say that I've ever seen that personally.

The method from Microsoft was a way to do the same thing in a way that
wouldn't always work. Do you remember Floppy Drives? Remember how cheap
and shitty they were? They were not very reliable to begin with, and
it's likely that even if it worked before there might still be
mysterious times when a disk was inserted and this method wouldn't work.
Microsoft made a good choice here, but rather than acknowledge that
you'll just bitch more and fish more crap from the excuse box.


That comment is the copyright of the poster, yada yada yada.

__
 
That's interesting. I had always assumed that apple's had smarter floppy
hardware, heh.

I think this post from /. user Jamie's Nightmare sums it up well:
Click to expand...
You're a bit out of focus here. It worked well on the Mac and the Amiga
because the floppy drives themselves were different. The hardware was
designed to signal the machine when a disk was inserted via a
switch/sensor inside the drive that was depressed when the disk was
inserted. Similar, but in a different location than the "write protect"
and "high density" sensors. This method is simple and it works. The only
real point of failure is the possibility of the switch going bad, but I
can't say that I've ever seen that personally.
Click to expand...

The "high capacity diskette drive" that shipped with the original IBM
PC/AT had an optical media sensor that signalled the controller via a
DISKCHANGE pin on the interface. When the user inserted a diskette, a
flip-flop would be set. A STEP pulse from the controller would reset
the flip-flop.

The double sided 5.25" diskette drive had no such sensor or interface
signal. However, we are talking about a 1995 OS, not DOS, so
presumably we would be focusing on 3.5" drives.

AFAIK, the only difference between Amiga and PC drives was in the
READY and DISKCHANGE signals. The PC didn't use the READY signal, and
the DISKCHANGE signal was on a different pin.

Some time ago I built an adapter circuit to convert a PC drive for use
in an Amiga:
http://groups.google.com/group/comp.sys.amiga/msg/6e89eb6a0986e1ff?dmode=source

- Franc Zabkar
 
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