Detailed documentation at URL given above.

(1) Calcomp DrawingBoard III digitizing tablet fails to initialize as xinput device at startup due to timeout error. From /var/log/Xorg.0.log:

(WW) Timeout while reading Calcomp tablet. No tablet connected ???
(EE) Unable to query/initialize CALCOMP hardware.

User fix in xf86Calcomp.c:  At line 787, change "int retries = 5;" to "int retries = 100;"

(2) After fixing (1), "xinput list TABLET" retrieves "7616" from the driver as the tablet axis 1 limit instead of the correct number, "24000".

User found error (missing line of code) in xf86Calcomp.c.  At line 608 change
  
         priv->max_y = (int)buffer[5] + ((int)buffer[4] << 7);
to

         priv->max_y = (int)buffer[5] + ((int)buffer[4] << 7)
                                        + (((int)buffer[3]&0x03)<<14);

(3) "xinput set-pointer TABLET" fails on calcomp tablet. 

X Error of failed request:  BadDevice, invalid or uninitialized input device
  Major opcode of failed request:  146 (XInputExtension)
  Minor opcode of failed request:  12 (X_ChangePointerDevice)
  Serial number of failed request:  12
  Current serial number in output stream:  12