Just downloaded the latest copy of Mach 3  and it still has a problem I reported in ver. (.068) with power off resets. I have my spindle controls setup on two relays, one for each direction. They are controlled by pins 8&9 and are active low. When I reboot my PC and load Mach 3 Mill both pins go active after I reset. They will stay that way and even do some strange toggles until I cycle the spindle 2 times in the diag screen. I can move the other axis's and it still will not set these pins correctly. Luckily my relays prevent the possiblility of both being on at the same time so I didn't have a shop full of smoke. Obviously I do not want the machine coming up with the spindle on however so this needs addressed. After this first episode I can close and open Mach 3 all day long and it works fine. Just the first power on load causes the problem. 

Another note is that before the Mach software loades the output pins are inactive (High).

The hardware is a P4 3.2Ghz running XP. Anyone have a clue what is going on?

So this problem is related to pin 15 which I have setup for ESTOP input. Even without the software loaded if I pull pin 15 low it freaks out the parallel port. XP must be doing something with this pin. I'm researching that or if anyone has run across this before please let me know.

I Found the problem!!!!

So here's the deal. Later versions of XP will poll the parallel port until it has been accessed every 5 seconds. Toggling any input pins will cause XP to query the parallel port to see what's there. This does funny things to all the output pins. In my case when I toggle my ESTOP button which happens before any other parallel port access it would trigger this query and mess things up. This would clear up after I toggled the spindle on and off a few times. XP would give control back to Mach3 and it would not look at the parallel port again until after a reboot.

So here is the fix. Add this entry to the registry.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Parport\Parameters\DisableWarmPoll

This registry entry should be of type DWORD and have a value of 1 (0x00000001).

Reboot and problem solved.

Thanks for sharing the info. I have never had this myself, what version of XP are you using?
Hood

Hood - XP SP2.

My guess is that the people using breakout boards are not having this issue. Especially if it has a charge pump on it. In my case however I have custom opto rerealy and direct switch inputs to the parallel port. Here is the test procedure i used.

Hook up two LED’s with resistors to pins 8 & 9. Hook a grounding switch to pin 15 or any other input pin. This will also require a pull up resistor. Reboot the PC. After reboot and before running any software look at the state of your LED’s. They should be on. Now ground your input pin and wait 5 sec. If you have a later version of XP the LED’s will both go out. Also pin 2 will pulse FYI.

Load Mach three and notice they remain out. Now toggle the spindle (set it up on pins 8 & 9).  After a couple toggles the LED’s will start responding how you would expect.