[chuckknigh]

I remember, a few months back, seeing a post on either this site or DIY-CNC, stating that a floppy drive had a driver circuit built in. Fair enough...it would have to have one.

But, I also remember That someone said you could control them, directly, just by exciting certain pins on the floppy connector. I looked up the pinouts, and there is a pin marked direction, and some others labelled things like drive 1 motor enable. Sounds like it might take step and direction inputs, directly.

Does anyone have this information? It sounds perfect for a simple experimental unit...

-- Chuck Knight

[vladdy]

not directly from the connector that normally goes to your motherboard..
internally on the board I'm not sure, but I'm thinking probably not...
They are designed to basically spin rather than individual steps, more rotational speed constant and timing for data as opposed to individual 'step' commands.. the head actuator itself would have something similar to a 'counted increment' step mode, but not the spindle motor..

...enjoy..

[High Seas]

I remember, a few months back, seeing a post on either this site or DIY-CNC, stating that a floppy drive had a driver circuit built in. Fair enough...it would have to have one.

But, I also remember That someone said you could control them, directly, just by exciting certain pins on the floppy connector. I looked up the pinouts, and there is a pin marked direction, and some others labelled things like drive 1 motor enable. Sounds like it might take step and direction inputs, directly.

Does anyone have this information? It sounds perfect for a simple experimental unit...

-- Chuck Knight

CHUCK - Your ideas sounds too cool to be real. ( I may have torn all my old floppy drives down).
Is this the info you were looking for:
http://www.epanorama.net/circuits/diskstepper.html

about midway down under: "Disk drive interface stepper motor control signals"

Hope that helps - if not share the results of your digging too.
:cheers: Jim

[chuckknigh]

I just looked at that site, and it looks promising. There is a connector pinout for a parallel to floppy cable, that basically says I can do exactly what I had heard.

Notice, specifically, pins 18 and 20 on the connectors. Step and direction.

Next time I go to Dallas I'll get some connectors, and wire it up...we don't even have a Radio Shack in my little town. (Like RS would do any good!) Hmmm...I wonder if I have a floppy cables left in any of my old PCs? Maybe...a lot of them have been scavenged, but maybe there are a few left.

-- Chuck Knight

P.S. Thank you for that site URL -- I've pulled out the relevant information, for everyone's benefit:

<HR>
<I><B>
PC/AT disk drive signals

PC/AT computers use those disk drive signals in the following way. In this system the drives are jumpered to be type A or B depending the situation. Usually PC and AT systems use a special cable which changes singal positions of drive A and B motor on and select signals between disk drive connectors. This makes it possible to have both drives to be jumpered as drive A and one drive works in this way as A and another as B.

Pin Function Direction

1 GND
2 High density sel ???
8 Index pulse from drive
10 Motor on A to drive
12 Drive select B to drive
14 Drive select A to drive
16 Motor On B to drive
18 Direction to drive
20 Step pulse to drive
22 Write data to drive
24 Write enable to drive
26 Track Zero from drive
28 Write Protect from drive
30 Read Data from drive
32 Select Head to drive
34 Disk Changed ???
3-33 Odd pins are GND

<HR>
PC parallel port to stepper-motor interface

This is a simple example how to control disk drive stepper motor using PC parallel port. I expect that the drive is jumpered to be as drive A. The parallel port pin numbers are according the 25 pin connector numbering which is in the the back of your PC.

Connect parallel port pin 20 (ground) to disk drive connector pins 17 and 19 (ground). Connect disk drive connector pin 14 (drive select A) to disk drive connector 17 (ground). Connect parallel port pin 2 (D0) to disk drive connector pin 20 (step pulse). Connect parallel port pin 3 (D1) to disk drive connector pin 18 (direction).

Parallel port (25 pin) Disk drive (34 pin)

2 ------------------------- 20
3 ------------------------- 18
+--- 14
20 ---------------------+--- 17
+----19


In this way you have made a cable with which you can easily control the stepper motor using parallel port datapins D0 and D1. Those pins can be easily controlled in your software by directly writing to parallel port hardware. You can't use the DOS, BIOS or other operating system functions, because this interface does not generate the handshaking signals those routines need.
</B></I>
<HR>

[High Seas]

Next time I go to Dallas I'll get some connectors, and wire it up...we don't even have a Radio Shack in my little town. (Like RS would do any good!) Hmmm...I wonder if I have a floppy cables left in any of my old PCs? Maybe...a lot of them have been scavenged, but maybe there are a few left.

Thanks for distilling the data Chuck - I saw it and didn't have time to work thru all the details and it looks promising!

Digikey vs RS? They mail and quickly - maybe JAMECO for the connectors as well - In my little town(s) I gotta use those guys alot. (+ Dick Smith, etc)

Planning on a mini-mini machine?

:cheers: Jim

Just recalled a page I bookmarked a few back:

http://www.nhcad.com/flpystpr/index.html

has some nice "handholding" to get thru the setup

[mujahid]

Dear as the information is available on the this site Using disk drive motors
can any body help me to use this floppy disk board to run a biger stepper motor, how to amplify it signals.
thanks

[irving2008]

Dear as the information is available on the this site Using disk drive motors
can any body help me to use this floppy disk board to run a biger stepper motor, how to amplify it signals.
thanks

It would take a lot of components and some difficulty to do that, starting with working out exactly what signals you are trying to amplify - by the time you are finished you would probably have been able to build a proper driver to start with. There are many easier and cheaper options to drive a 'real' stepper motor now with ready made boards from many suppliers and eBay or, if you must build your own (which isnt always cheaper), use a proven design; try one of the many examples at PMinMO.com...