TB6560 TB6565 3rd gen 4-axis no volts db25 pin 01

Hi, I'm configuring one of these for a mill-conversion: www.ebay.co.uk/itm/281364657882?ssPageNa...id=p3984.m1439.l2649

(Yes, another tight-fisted crazy! )

Thanks to the wealth of information in the linuxcnc project I now have four motors turning smoothly and satisfactorily.

But my setup only works when i apply a +5V pull-up to pin 1 on the parallel port. For my board this carries a composite, x,y,z-enable signal.

Inspection of the hal-configuration gui shows that the pin is set appropriately, i.e. goes TRUE when the AXIS power button is depressed and the motors are energised (provided the +5V pull-up is applied to pin 1 ).
Without the pull-up connected, I also verified the pin 1 voltage voltage with a DVM and then an oscilliscope. It did remain zero whatever the logic value.

Having to install this pull-up makes me feel a bit dirty; and suspicious that I have misunderstood or missed something important.

1. Is there strangeness in the board design that requires something like a +5V signal on the ESTOP input before it cooperates?
2. Have the wrong sort of parallel port or have I configured wrongly It's a pci express job with a Netmos chip that appears to be doing the job perfectly. (But my knowledge of parallel port modes is a bitscrappy) ?
3. Is there another cause that I haven't even imagined.

I'd really appreciate any comment that will help to clear the doubts before I move on to mechanical phase of the conversion.

Cheers

But my setup only works when i apply a +5V pull-up to pin 1 on the parallel port. For my board this carries a composite, x,y,z-enable signal.

My SWAG would be that the enable requires a strong source to operate (bit like the Gecko's charge pump not working unless you enable EPP mode).
The PCIe is undoubtedly 3.3v and probably cannot supply enough

See this thread re the Gecko problem
linuxcnc.org/index.php/english/forum/38-...el-port-card?start=6

regards