You could remove the dependency on hard coded pins by using the CW and CCW Leds.

How about OEMLed(11) ?
My list shows "Spindle CCW/CW if either is requested"

You need both LEDs to detect for ON just as you've used both outputs

Spindle rotating CW LED,   164
Spindle rotating CCW LED,   165

Fair enough then

If GetOEMLed(164) or GetOEMLed(165) then
  DoSpinStop()
else
  If GetVar(1601)=0 then
    DoSpinCW()
  Else
    DoSpinCCW()
  End If
End if

Seems better.

Will this work?
Brings all the code into the spindle-toggle button so no messing with M4/M5 etc

If GetOEMLed(164) Then          'was running forwards
  SetVar(1601,0)
  DoSpinStop()
ElseIf GetOEMLed(165) Then      'was running reverse
  SetVar(1601,0)
  DoSpinStop()
Else                                         'was not running
  If GetVar(1601)=0 Then
    DoSpinCW()
  Else
    DoSpinCCW()
  End If
End If

Looks good - just a typo - you've set 1601 to 0 in both

Here's one for you though - what happens when you start Mach and hit the spindle button for the first time i.e. when it's off?

OK, sorted the typo...

Spindle start by toggle from first go, hmmm?

Are the #vars saved when Mach is closed?

If yes then it would start in the same rotation as left the day before - good or bad, I don't know.

If no then it would start forwards the first time as the #var would be zero, I guess we can add a reset macro to the INIT line that sets the #var however we want for the first time?

Depends if it's an issue or not i guess

If GetOEMLed(164) Then          'was running forwards
  SetVar(1601,0)
  DoSpinStop()
ElseIf GetOEMLed(165) Then      'was running reverse
  SetVar(1601,1)
  DoSpinStop()
Else                                         'was not running
  If GetVar(1601)=0 Then
    DoSpinCW()
  Else
    DoSpinCCW()
  End If
End If

We'll make a programatist of you yet Dave  

500-600 are persistent (they're saved in the xml) so you're good to go.

Ha, simple stuff i can handle, I do Visual Basic programming at work sometimes so this is pretty much the same.

Good to know about the 500-600, now if only there was a list of variables or a way of finding free ones

Hi , thx for help need to study all that and try , will let you know if it will work, I thought that somebody had that issue so there exist bulletproof solution and I only could not find it, also interesting info on destroying variables (BASIC)