Windows 95 Almost Autodetected Floppy Disks

bonch writes "Windows 95 almost shipped with a technique for detecting whether a floppy disk was inserted without spinning up the drive. Microsoft's floppy driver developer discovered a sequence of commands that detected a disk without spinup — unfortunately, unspecified behavior in the floppy hardware specification meant that half the drives worked one way and half the other, each giving opposite results for the detection routine. Microsoft considered a dialog prompting the user to insert a disk to 'train' the routine, but the idea was scrapped."

Comments

Um

[linumax]

Why not do the behavior detection on first instance a floppy disk was used?

Re:Um

[enjo13]

The point is you don't have to do even that. The routine would look something like:

- User initiates action with the floppy drive
- Run the auto-detection routine to see what answer you get
- Spin up the drive and check to see if something is in the drive
- Compare that with the pre-spun result to see what answer you get.

Something along those lines. There are several variations on this that would work and never require you to interact with the user at all.

Re:Um

[RiotingPacifist]

problem: some users are idiots
solution: treat all users like idiots

I know its not the msway but a would regkey you could manually set have been that hard?

Re:Um

[mccdyl001]

damn wish i had mod points. and a shift key for that matter... anyway, surely there was a way for the operating system to poll the system using these 'magic' system commands to check if a disk had been inserted. so poll the system, see what it says - either a 1 or a 0, then spin up the drive and see what it actually says. heck do it as part of the system install. take a snapshot of the floppy drive device name or something at the same time. if the device name changes re-run this technique, cause if you swap the floppy with another drive which reports the same device name it'll still report 0 or 1 for the same type of disk insertion scenario so you fine, and if the floppy device name is diff, then re-run this technique. anyway, as part of the system install you could have polled if the disk was there, taken the answer, then actually spun up the drive and checked and bingo, your training is done1 damn what i could do with a shift key right now....

Re:Um

[coryking]

floppy device name is diff

The only way the OS even knew your floppy drive existed was through the bios. If you told the BIOS you had a floppy drive and you didn't, the OS would be none the wiser. And if the OS didn't know if there really was a drive or not, I somehow doubt the technology could even support unique device ID's like modern stuff.

In other words, your plan would work if floppy drives had device ids, but they dont, so your idea won't work either!

Re:Non-system disk or disk error anyone?

[VGPowerlord]

Of course Windows damn well knows automatically when a floppy is inserted...
The number of times I had to remove a floppy from my mom's non-booting PC is probably higher than the number of bytes in Wikipedia's servers.

Congratulations on not reading the article or summary.

First, this feature was talking about checking if a disk is present without spinning up the disk. To boot from a floppy, a computer spins up the disk and looks for a boot sector.
Second, that would be the BIOS, not Windows, checking the floppy during the boot process. It checks the devices in the order it's set to. Back in the mid 90s, this was generally floppy, then IDE, then SCSI. A few people with good hardware had CD-ROM in there, too.