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"B:" diskette not seen in Win98SE -- SOLVED


Laser98IX

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This may help (this is how a floppy cable looks like and which end is which ;)):

Thanks, jaclaz. This really is the style of diskette cable currently installed on the machine. The problem is somewhere else.

Still looking ...........

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Gotta ask, is the second drive enabled in the BIOS? I know some BIOS allow the second drive {and the 1st} to be disabled. If that were the case, because 98 goes through layers, it might not see a drive that DOS sees... At least I'd check that situation.

tom

Forgot to add, that some BIOS allow the drives to be swapped if desired. Lets complicate things just because we can!

Yes, the second drive is enabled in BIOS. Booting to DOS and copying files from A: -> B: or B: -> A: works fine.

I agree, Win98SE does NOT see what DOS sees, which is why I'm not able to see the B: drive in Windows Explorer, but I'm able to use both diskettes in DOS.

Yes, I've also seen the option in BIOS regarding swapping the diskette drives, and no, that option is not selected.

Because of some local scheduling problems I have not been able to swap out any of the diskette drives yet, although as I said above I have four more to try. I'll update this thread after I try those drives.

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Option 1. Try finding and re-installing the drivers for your SBC's chipset.

Option 2. May be risky, but delete the floppy and its controller in Device Manager and rescan for "new" hardware.

Side note - Old 5-1/4 in ancient IBM's (5150's) didn't have the "twist" in the cable and you had to change the ID as DS0 or DS1.

I don't think so. It was IBM that introduced the hair-brained (hare-brained?) "twisted floppy cable" scheme to the world. OTOH, I had a clone by a company called Eagle and that used a straight floppy disk cable, so it supported up to 4 floppy drives, yet the case could only fit two! BTW, I also used a 5150 at the time, and that definitely used a twisted floppy disk cable.

Joe.

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I don't think so. It was IBM that introduced the hair-brained (hare-brained?) "twisted floppy cable" scheme to the world. OTOH, I had a clone by a company called Eagle and that used a straight floppy disk cable, so it supported up to 4 floppy drives, yet the case could only fit two! BTW, I also used a 5150 at the time, and that definitely used a twisted floppy disk cable.

Hmmm.

I have one word for you ;), "Shugart":

http://pinouts.ru/Storage/InternalDisk_pinout.shtml

jaclaz

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BWAHAHAHAHA!!!!! I had an ORIGINAL (unmodified) 5150 - NO TWIST! Just like the HDD's (that had an "odd" cabling - EXTRA WIRES). Look up MFM and RLL (and look up the old Floppies) and get more info.

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BWAHAHAHAHA!!!!! I had an ORIGINAL (unmodified) 5150 - NO TWIST! Just like the HDD's (that had an "odd" cabling - EXTRA WIRES). Look up MFM and RLL (and look up the old Floppies) and get more info.

Interesting. My 5150 was '83 or '84 vintage, 4164 based, and came with a contorted (twisted) floppy cable configuration. To this I added a Tallgrass Technologies HD interface card and external HD (12MB, as I recall). Perhaps yours was the earlier 4116 based version of the 5150? AFAIK, there were at least two versions of the 5150 motherboard, and no doubt, different versions too of floppy disk controller card. So assuming we are both right, IBM must have transitioned from the standard Shugart cabling to their contorted version during the life of the 5150.

Interesting historical trivia, not sure how useful it is to the problem at hand. ;)

Joe.

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Post#16 - the "twist" I referred to.

More info on IBM 5150 Floppy cabling (ref. jaclaz' Shugart note).

4116 < 4164

I no longer own it - GAVE it away - 2-20mb HDD's, 2-5-1/4 Floppy , Sound, (etc etc). I assure you, I know what I'm talking about, including the 3-1/2 inch DSn Switch/Jumper "oddity" on older ones (works same way as IBM Floppies - I tried one of them on the 5150).

Useful to problem at hand? Neither is your information.

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More info on IBM 5150 Floppy cabling (ref. jaclaz' Shugart note).

4116 < 4164

I no longer own it - GAVE it away - 2-20mb HDD's, 2-5-1/4 Floppy , Sound, (etc etc). I assure you, I know what I'm talking about, including the 3-1/2 inch DSn Switch/Jumper "oddity" on older ones (works same way as IBM Floppies - I tried one of them on the 5150).

Thanks for that link to John Elloitt's page, lots of useful details there.

I notice it says ...

When IBM built their first PC, they didn't think the power supply was up to having all the drive motors running at once, so they designed a system with separate motor control for each drive. A twist in the cable between drives B and A means that each drive sees a different motor control signal.

... which is the first explanation I've seen about why IBM contorted the Shugart interface (OK, I haven't exactly been looking), and is perhaps plausible, as I recall the power supply in the 5150 was quite underpowered by today's standards, something like 63W (if I recall).

@Laser98IX : Have you tried either option suggested in my first posting (#18)?

Joe.

Edited by jds
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A resource for the good ol' times lovers ;):

http://www.minuszerodegrees.net/

Specifically:

http://www.minuszerodegrees.net/images3/floppy_crossover_cable_wiring.jpg

jaclaz

Wow!!! What a fantastic resource, thank you so much jaclaz! :yes:

Two thing I found noteworthy :

Firstly, the page http://www.minuszerodegrees.net/failure/failure%20-%203lt.htm suggests there are two possible polarities for three-legged tantalum capacitors. Unless some evidence indicates otherwise, I believe this is hypothetical and only the negative-positive-negative polarity actually exists.

Secondly, page 2-108 of the scanned IBM document "IBM_5150_Technical_Reference_6025005_AUG81.pdf" (yep, from 1981) shows the following signals on the floppy diskette interface (among others, of course) : Motor Enable A, Drive Select B, Drive Select A, Motor Enable B

Joe.

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Option 1. Try finding and re-installing the drivers for your SBC's chipset.

I've located the Intel 440BX chipset installation files, but they're from Intel and NOT Advantech, who mfg'd the board. Intel suggests I don't attempt the install from their files, and I'll have to read through why they don't want me, as an end-user, to do so.

Will review if the hosted files are newer or older than the installed INF files on my machine.

In order to prevent a complete (versus an incomplete) disaster I'm in the process of backing up the entire PCA-6176 Win98SE "C:" drive to an external archive. Once that's finished, and after I've done the file comparison, I'll attempt the i440BX INF update. I'll swap the diskettes first, which is what I said I'd do anyway.

Option 2. May be risky, but delete the floppy and its controller in Device Manager and rescan for "new" hardware.

This may sound strange, but it's actually easier for me to try Option 2, because I can always reinstall the controllers and drives afterward if that doesn't fix the problem. But like I said just above I still need to swap out the diskette drives.

Backup is complete. Will shut the machine down and swap the diskette drives now. Report status later tonight.

Thanks, Joe. As the guys at the ISS are always saying to the folks at the MCC -- "In work."

@Laser98IX : Have you tried either option suggested in my first posting (#18)?

Sorry for the delay in responding.

I've got the configuration installed in a bit more "permanent" temporary location for the moment, and I've taken some photos of the H/W and the BIOS screens. I'll upload them shortly, as long as I don't exceed my maximum of 500K of global upload quota. I've got to edit the image files so they're not quite as large and take up too much space as I might normally use or exchange.

Thanks again, Joe.

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Firstly, the page http://www.minuszerodegrees.net/failure/failure%20-%203lt.htm suggests there are two possible polarities for three-legged tantalum capacitors. Unless some evidence indicates otherwise, I believe this is hypothetical and only the negative-positive-negative polarity actually exists.

Yes, AFAIK -+- (+ in the middle) was the only availability of the package, it was designed originally to avoid possible polarity exchange when assembling the board.

jaclaz

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Problem Solved!!!

Update 08: Substituted both diskette drives for different model units with no change.

Update 09: Deleted diskette drive and adapter in Device Manager and rebooted.

--- O/S found "new hardware" and installed diskette adapter and both diskette drives

Now Win98SE can "see" both diskette drives in Windows Explorer and can read and write as well.

The only explanation I can come up with is during O/S installation only one diskette was installed, so the addition of the second drive later on wasn't seen by the O/S because the drivers for it were never loaded.

Thanks to jds for making the suggestion. I'll pay attention from now on and be sure to have all hardware available during an O/S installation.

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I know that, as often happens :w00t:, this is off topic :ph34r:, but not too much ;).

I happened to land here:

http://www.fybertech.com/forums/index.php?topic=1020.0

and this is the "better" place to put it I can think of :unsure:.

So, floppy drives have always been an item of interest to me. My ultimate goal is to read a 1.44MB floppy's contents using my own homebrew floppy controller. I haven't reached that point just yet, since I still have to create a PLL to keep in sync with the bit stream, not to mention decode the MFM, neither of which I've done before. But I did think up something recently which doesn't require that level of complication, and might actually be useful. And that's a floppy disk eraser! It came to mind when I found a ton of old floppy disks that I needed to erase.

To do it, I interfaced with the parallel port of the PC for now. That's definitely not fast enough to read or write to the floppy, but it's fine for controlling the signals to manipulate the heads and motor. I connected with 7 signals: the track 0 detection, drive select, motor enable, step direction, write enable, and head select. All are outputs except the track 0 detect, which you use to know when you've pulled the heads back all the way. The basic procedure is: select the drive, enable the motor, pull the head back to track 0, then for the next 80 tracks you activate the write head for both sides of the disk, waiting long enough for one rotation for each erase, then step the head to the next track. After doing that multiple times to cover the entire disk, you drag the head back to track 0, then deselect the drive.

....

The reason this works to erase the disk, despite not sending it any data, is because activating the write-enable line also enables the erase head. It's like writing lots of 0s to the disk, pretty much. Even the floppy controller in a PC can't make the disk this blank to my knowledge, because during a format it's writing track information back to the disk. We just leave the write data pin disconnected, and since the drive uses TTL logic, it should float "high" automatically. All the floppy signals are inverted, so that makes the data write pin indicate binary "0" all the time.

Useless? :unsure:

Maybe yes, maybe no.

jaclaz

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