Just comments

Hi,

I am just having *too* much to do ! - and I don't get much done
:-( , so I have just listened in once in a while lately.

The floppy driver & EMC, was just an idea I came up with, but I
haven't had any time to test it myself. But I would be very
interested to hear if anyone would give it a try. So, I will send
you the pinout again.

Here is the edge connector on a floppy drive:

-- ---------------
_| || |_

I have tried to draw this above. There is 17 gold plated "fingers"
on each side of the circuit board, and there is a notch after the
first 2. If you look straight into this, and you have the notch on
your left hand side, then the numbers on this connector is:

On the bottom, they are numbered from 1,3,5,7,9,.....33
On the top......., they are numbered form 2,4,6,8,10...34

If you use the floppy cable, - then you have a matching connector
for these edge connectors, and the cable is used for both A:\ and
B:\ floppy drive.
There is a twist on the cable, for drive B:\ . ( wires 10-16), and
on the other side a connector like this:

1 3 5.....
----------------------
# # # # # # # # # # # # # # # # #
# # # # # # # # # # # # # # # # #
---------------------
2 4 6 .........

Numbers looking into the header. The numbers correspond to the
connector on the Floppy drive. ( There is often a red or blue mark
on the ribbon cable, - this identify wire number 1, and will be the
same as the no 1 pin/edge connection.

( -------- here is from my earlier email:
----------------)

Pin 10 = input Motor Enable floppy no. 1
Pin 12 = input Select floppy no. 2
Pin 14 = input Select floppy no. 1
Pin 16 = input Motor Enable floppy no.2

On an old 5 1/4 floppy drive, they either have a twist on the cable,

so you select either floppy 1 or 2 ( drive A or B ) - but there may
be jumpers on the
floppy drive as well, so you can select which one it should be. The

Motor Enable signal will spin it up, - you could "pretend" you
started a pump or spindle on a real machine.

The select signal, could be wired to a motor enable signal from the
EMC, - and the led on the floppy should turn on.

Then,

Pin 18 - input Direction
Pin 20 - input Step pulse

Here you can run the head in or out.

Pin 26 - output Track 0

This can be used as an end switch input, or a "home" input

All odd numbered pins is ground.

--------------------------------

All you need is some wire ! You have power/motor/ switches/led/
etc.

I have not checked the EMC step motor interface or the Machine
control IO, but maybe there could be some use for the index pulse
output on pin 8, if you have a floppy inserted. This could count
revs, or what ever. If you added some parts from another floppy, -
you could mount the optical sensors, cut some holes in the floppy,
and make encoder pulses. But if used as it is, - it could be a nice

little testing device. There should be a little G code program to
run.

Add floppy drives, and you could run run x, y, z axis. You could
even make a miniature machine out of it.

So maybe there should be made a little cable - to interface a floppy

drive as a test device ?

( ---------- end of earlier email ----------------)


I think you could wire this directly to the parport, - to the
step/dir pins as you find in the EMC documentation.
If I were going to test this, I might have disconnected the motor
axle, so it could spin freely.

If you use the floppy cable, you can only use one drive, as the
step/dir signals is on the same wire. You select which drive, by the
"select" signal, that is pin10 for drive A, and pin12 for drive B.
In other words, this signal has to go high in order to use the
motor.

Okay, - you should be able to run the motor with EMC. For old
360Kb floppy drives, I think the electronics will run it in full
step, but on 1.2M drives,
they may have used half step. ( I am not sure )

Most drives use bipolar motors, - that is it will have 4 wires.
For large motors, you could wire up 4 power transistors on this
output, - and drive what ever size you would like. You could rip
out the circuit board, - stack them or what ever, - it would not
look very nice, but it would work.
For stuff you make, you even get ready circuits for home switch and
such. The photo interrupted end switch is easy to mount on anything.
( this signal should be output on pin.26 ) The photo interrupt
signal that reads "the hole in the disk" - the index signal is
output on pin. 8, and there may be a sensor for the write protect
that you could find some uses for. This should be output on pin.28 .

NOTE: these signals is enabled with the drive select signal. The
signal is multiplexed on one and the same cable. So, don't use more
than one drive on the cable.

EXTRA NOTE: let us know how it works out !

//ARNE