Two of the pins at the EDC (External Compass) will need to change position, but the number of wires is the same. You will also need to upgrade your EDC-D10 to an EDC-D10A.
The transponder connection for a D10A is serial instead of the parallel found on the D10. This works with some newer transponders like a Garmin 327/330, but not with older designs. If you are using the EFIS as an alititude encoder and need parallel (grey code) than you would need to buy a serial to parallel converter from us.
Note that the EFIS-D10A's magnetic calibration procedures and algorithms are the same as on the EFIS-D10. However, the EFIS-D10A does not require the laptop to perform the calibration. It is all done on the EFIS itself. Since you seem to be having trouble with the connection between the EFIS-D10 and the PC during calibration, you may find the EFIS-D10A easier to calibrate with.