What apple iie board is this

[sumguy999in1]

Found this in an apple iie. Anyone know what it is?

 

[hornbetw]

According to this Ebay listing it's a stepper motor driver.

 

[sumguy999in1]

What’s a stepper motor?

 

[hornbetw]

Stepper motors are used to move the heads on floppy drives. They are easy to make move a precise amount in discrete steps.

 

[GiGaBiTe]

Stepper motors are used for more than floppy drives. That machine could have been used in an industrial setting. With the 8 LEDs, possibly it was able to control 8 motors.

 

[Eudimorphodon]

It could have been used for any number of things; driving a robot, CNC machine, or plotter would be high on the list.

A common counterpart to a card like this would be a data acquisition module for sensors associated with whatever this controlled, although in some applications you might just get by with using, say, the joystick port lines. (And this card itself might have inputs, no idea without the manual.)

 

[daver2]

I drive a nuclear reactor using stepper motors! No kidding...

With 8 LEDs you can drive four or two stepper motors (depending upon the winding configuration).

A stepper motor has a permanent magnet that is 'dragged around' by multiple coils. Each time the current changes in a winding, the rotor is dragged around by a fixed angle.

The good thing about a stepper motor is that it 'fail freezes' (i.e. it stays in its last position).

In an industrial setting, the stepper motor will drive pneumatic, hydraulic or high-power electrical equipment to increase the force and drive a substantial piece of equipment.

Dave

 

[sumguy999in1]

Thanks guys. Any reason to keep this card? If I could figure out something that plugged into it (there's a long parallel port attached to it) that would be awesome.

 

[daver2]

See if you can find the manual for it first.

There may also be some missing software to drive it also.

I suspect a couple of two phase or four phase stepper motors connect directly to it. But, the card could drive a power board (that you do not have). If you can find the manual, that will answer all of the questions!

Dave

 

[btb]

There would be an external board, like the Rogers R2D23 to go with it, which actually does the motor driving (this is more of a control card)

And yeah, if one was able to find software or documentation for this card, it could make it a very neat item to have. (Picture running a CNC lathe or something like that with an Apple II)

 

[dorkbert]

MC6840P is programmable timer.

 

[daver2]

MC6840P is programmable timer.

Correct, but that just provides an accurate timing signal. It could be the phase drivers are built onto the board, but they may still be done in software under control of the timer (via interrupts).

It would be nice though if you just wrote a value to a register and the associated stepper motor just drove by that many steps in the specified direction. That is the way our cards at work operate - but they are intelligent cards.

Dave