Drives confirmed working with KryoFlux

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brightcaster
Posts: 200
Joined: Fri Nov 08, 2013 10:48 pm

Re: Drives confirmed working with KryoFlux

Post by brightcaster » Sat Jul 20, 2019 3:41 pm

As far as I remember IBM inverted some control signals! So it's not done with a simple adapter or twisting some wires...

David

brightcaster
Posts: 200
Joined: Fri Nov 08, 2013 10:48 pm

Re: Drives confirmed working with KryoFlux

Post by brightcaster » Mon Jul 22, 2019 11:15 am

Once again I have to correct myself! It's not a matter of inverted signals with the IBM PS2 drives but a change in position of pullup resistors. The PS2 floppy drives have some pullup resistors on board which are usually found on the controllers side. So they may work with some modification....

http://www.vcfed.org/forum/showthread.p ... post398805

In my opinion, it's better to sell a working PS2 drive than to use it with the kryoflux, as these drives are nowadays becoming very rare and much more expensive than a well-functioning standard floppy drive!


David

curtcool
Posts: 4
Joined: Thu Aug 08, 2019 9:25 am

Re: Drives confirmed working with KryoFlux

Post by curtcool » Sun Aug 11, 2019 1:39 pm

Old IBM 5,25" drive - Type 0386-001 - Can it work?

A while ago I bought an old 5,25" drive for not too much money, aiming to try it on Kryoflux. It's supposed to be a standard 1.2mb drive but ... Since I haven't been able to locate it on the net anywhere, I can't be sure...

Now, I have been trying out for a bit but when calibrating, I get the message "control command rejected by the drive". The drive spins, but, as they say, no cigar.

Now, I see 4 possible reasons why:

a. The drive doesn't work with Kryoflux¨
b. The jumpers on the drive (I count 7) needs to be set correctly
c. Connection is somehow bad, I'm not expert on 5,25" drives and could have taken a wrong turn connecting the cable
d. It needs the "slow" firmware.bin mentioned in the Kryoflux manual, which can't be found in the archive.

So which is it? Any experts here who could be of help, it would be appreciated.

The 9 jumpers I can find are:
4 pairs of jumpers located near the data plug - named 0,1,2,3 - seems obvious to me that these are used to set the drive ID - I tried with both 0 and 1.

2 more pairs on board, related text seem to be 4, dc and 24

3 pins with text s2, tn, rd

2 pins with text 96, s3

2 pins with text s4, dh

Best regards
Frank / Copenhagen, Denmark

ZrX
Posts: 542
Joined: Tue Dec 06, 2011 9:09 pm

Re: Drives confirmed working with KryoFlux

Post by ZrX » Sun Aug 11, 2019 1:50 pm

curtcool wrote:
Sun Aug 11, 2019 1:39 pm
Old IBM 5,25" drive - Type 0386-001 - Can it work?

A while ago I bought an old 5,25" drive for not too much money, aiming to try it on Kryoflux. It's supposed to be a standard 1.2mb drive but ... Since I haven't been able to locate it on the net anywhere, I can't be sure...

Now, I have been trying out for a bit but when calibrating, I get the message "control command rejected by the drive". The drive spins, but, as they say, no cigar.
Try with the drive without power to move the heads towards the spindle, then power on the drive and see if it auto-resets the heads back to track 0. If not try the calibration and it should move the heads to track 0 before doing calibration.

If the heads don't move to track 0 there's something wrong with the drive electronics. If they do it could be the jumpers, or something else.

SomeGuy
Posts: 221
Joined: Wed Feb 18, 2015 8:18 pm

Re: Drives confirmed working with KryoFlux

Post by SomeGuy » Sun Aug 11, 2019 2:48 pm

It sounds like IBM just slapped their own label on the drive. Post some pictures of it an perhaps someone can ID the actual model.

If this was not intended for a PC/AT or compatible then the jumpers very well might need to be changed.

curtcool
Posts: 4
Joined: Thu Aug 08, 2019 9:25 am

Re: Drives confirmed working with KryoFlux

Post by curtcool » Mon Aug 12, 2019 2:46 pm

ZrX: I will try this.

In the mean time, here are some photos of the drive, should anyone be clever enough to ID it :).
Attachments
Label.JPG
Label.JPG (17.39 KiB) Viewed 157 times
Front.JPG
Bottom.JPG

curtcool
Posts: 4
Joined: Thu Aug 08, 2019 9:25 am

Re: Drives confirmed working with KryoFlux

Post by curtcool » Mon Aug 12, 2019 2:48 pm

And one more:
Attachments
Top.JPG

SomeGuy
Posts: 221
Joined: Wed Feb 18, 2015 8:18 pm

Re: Drives confirmed working with KryoFlux

Post by SomeGuy » Mon Aug 12, 2019 7:56 pm

Yea, that's what I thought. Goofy mainframe/mini stuff.

The actual IBM part number on that label is 1685550.

Searching turns up: 1685550 · OEM IBM 5364 FLOPPY DRIVE

and pulling up IBM 5364:

http://www.ricomputermuseum.org/Home/eq ... 364-s36-pc

"The IBM model 5364 was called the "System/36 PC" or "Desktop 36" (and also, informally, the "Baby/36" by some - but this name was later attached to a software program produced by California Software Products, Inc.). The 5364 was a June 1985 attempt by IBM to implement a System/36 on PC-sized hardware. Inside, there were IBM chips, but the cabinet size was reminiscent of an IBM PC-AT of the period. The machine had a 1.2 MB 5.25-inch diskette drive, which was incompatible with PCs and with other S/36s. The control panel/system console (connected via an expansion card) was an IBM PC with at least 256KB RAM."

Which tells us this drive is not IBM PC compatible, but does not say what the difference is, who actually manufactured it, or if it can be made IBM PC compatible. (It might involve more than just jumpers)

I'd suggest creating a new thread about this topic either here or on the vcfed.org vintage computing forum. It's likely some IBMer on the vintage computing forum would have more information.

curtcool
Posts: 4
Joined: Thu Aug 08, 2019 9:25 am

Re: Drives confirmed working with KryoFlux

Post by curtcool » Tue Aug 13, 2019 10:48 am

SomeGuy: Major thanks for your help. If nothing else, this will teach me to buy one of the drives already known to be compatible when available here in DK (it happens) - I didn't pay much for this one, and can possibly resell it. But can't help wondering how this ended up here, though ;). I shall try to find more information, but I reckon you are right that more than just changing jumpers is required to make it work with either Kryoflux or a normal (old) PC.

SomeGuy
Posts: 221
Joined: Wed Feb 18, 2015 8:18 pm

Re: Drives confirmed working with KryoFlux

Post by SomeGuy » Tue Aug 13, 2019 6:49 pm

Well, the #1 thing when buying a floppy drive is to know what the model and revision is, and make sure technical documentation is available for that model/revision.

Even a "compatible" drive can appear incompatible or broken if it was jumpered for a non-PC system.

In theory the Kryoflux should work with any "Shugart" style interface, but there can be some odd variations one might not expect. For example, 100tpi drives, drives that spin at different RPM speeds, drives that take power through the card edge connector (poof!), I've read about some double sided 8" drives that can emulate dual single sided units, the large System/36 apparently has some funky auto-loading 8" system.

And even then, there are smaller issues that the drive designers never thought of that affect Kryoflux users such as filtering of GCR signals and different bitrates, amount of write "noise" created when switching off write or splicing, access to extra tracks, or the ability to flippy mod. Honestly, the drives listed in this thread are a little vague about some of these.

Now that you know what the drive is from, who knows, you might even get lucky and sell it for more. Half the battle of selling something is knowing what you have.

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