If you are using steppers, another option is the Pico Systems Stepper controller. It supports up to 4 axes, and can be extended with another board for up to 8 axes. it can accommodate steppers with encoders, if you want that. It also has inputs for limit and home switches, and positions for 8 solid state relays to control spindle, coolant, etc.
An optional board can give an analog spindle speed output.
See
pico-systems.com/osc2.5/catalog/product_...ath=4&products_id=30
for more info. It interfaces via the parallel port. if your computer doesn't have a parallel port, you can get PCI or PCIe cards to provide that. (We sell the PCIe cards to assure they are compatible.)
This works out of the box with LinuxCNC, where a sample config file is provided.
Jon
