notes for xyz axis with Feed and Spindle override MPG

# this is a generic MPG hal to be used with a 7i76e board
# the MPG hal is designed for Linuxcnc 2.8 and later
# it will not work with older versions of Linuxcnc
#
# this version of MPG will only enable after homing 
# and axis is selected
#
# 
# in the  ini.  file
# under  HALFILE = custom.hal
# Add-   HALFILE = mpg_3FS.hal   
#
# 
# in the main hal file
# in the loadrt hm2_eth board section 
# insert  sserial_port_0=20xxxx
# 
# this allows 2 additional encoders to be chosen
# on TB5 while still utillizing a spindle encoder 
# on TB3
#
# use TB5 pins 1 and 2 for encoder 0
# use TB5 pins 3 and 4 for encoder 1 
# however encoder 1 is not utilized for this MPG hal
#
# this hal will utilize 1 MPG jogwheel for independantly controlling
# axis X, Y, Z, Feed Override, and Spindle Override  
#
# mux16 is utillized for jog increment selection
#
#
# TB5 inputs will be utillized with this hal file
#
# TB5 pinout is as follows
# pin 1 A                   encoder 0          
# pin 2 B                   encoder 0  
# pin 3 A                   encoder 1 not used
# pin 4 B                   encoder 1 not used
# pin 5 X axis select       input 20
# pin 6 Y axis select       input 21
# pin 7 Z axis select       input 22
# pin 8 4th axis select     input 23 not used
# pin 9 5th axis select     input 24 not used
# pin 10 inc a select       input 25
# pin 11 inc b select       input 26
# pin 12 inc c select       input 27
# pin 13 FO select          input 28
# pin 14 SO select          input 29