A parts list will be forthcoming, after I test it thoroughly. 
3/29 - All controllers (1-4) steps/dir function A-OK. Wahoo!

3/30 - The MOSFET heat controller has yet to be coded and burned.

Based on the Allegro 5804B unipolar stepper driver, this design uses jumpers to connect the optoisolated LPT data signals to the 5804B inputs. By using jumpers, instead of point-to-point traces, the LPT port data lines can be mapped any way the CNC software may require. 
 It also has an 8-pin socket to accomodate a hot wire temperature controller PIC (i.e. Picachof or the like). I plan to use a 12c671 with a panel mounted potentiometer as an AD variable input, and a PWM signal output to a IRL510 (a logic-level 5.6A MOSFET) to control the temp. I did not have room to add an optoisolator to the PIC inputs from the LPT port due to lack of space on the board. I hope it doesn't come back and "bite" me later.:( 

Steppers of any voltage may be used, as long as you select the appropriate zener diodes and power resistors, and apply a stepper voltage to the stepper power supply pad (mine is jumpered to 5V in the top-right diagram). For zeners, I'm using 1N4734 (1W 5.6v). 

Underneath the board, I have pads to which the resistors may be added. This allows you to "overdrive" a stepper whose rated voltage is lower than that of your supply. My test implementation uses 5.3V steppers, so I used no resistors, and simply jumpered the pads underneath. I also jumpered the stepper supply pad to the 5V supply. 

Traces on the top and bottom slave outputs 1 & 3, and 2 & 4 together. However, the traces can be cut to use each stepper controller independantly (for X,Y,&Z in a circuit board etcher or plunge-cut router) 


Allegro 5804B Thermal Characteristics.
The 5804 does have a thermal shut down mechanism which protects the output transistors when the junction temperature exceeds 165 degrees C. The 8054 can supply a max output of 1.5A per phase. Since the coils in my steppers are rated at .75A/phase, so I do not expect an overheat condition. However, I have 4 larger 4V steppers (Oriental Motor PH264A-01) which are rated at 1.1A phase. When I am able, I will test them as well, and see if this controller will support them. 

ExpressPCB
This board was designed using ExpressPCB's free circuit board software. It allows you to quickly create a double-sided board which can then be sent to their manufacturing facility via the internet. 
I use their miniboard service (the $59 deal for 3 identical boards) which is limited a 3.8" x 2.5" board. That's why I crammed so many components into such a tight space. 

It takes ~4 business days for the boards to arrive via Airborne Express.