These comments were in the .cpp file.
////////////////////////////////////////////////////////////////////////////////
// This Library is written for the Arduino Mega 1280/2560. See the ATmega1280/
// 2560 data sheet on how to connect your hardware to the External Memory
// Interface of the ATmega. I have successfully tested this library with a
// Mega1280 and the texas instramens bq3287EA Real-Time Clock. I used a 74ACH573
// transparent latch between the mega and the RTC as per the data sheet. I tied
// the AD7:0 pins from the mega(pins 22-29) to the AD7:0 pins of the RTC
// (pins 4-11). I also tied AD7 of the mega(pin 29) to D7 of the latch. Then I
// tied the EXTRAM pin of the RTC to the Q7 output of the latch to access the
// upper 128 bytes of ram on the RTC. Use the ExMem.enable() function to set up
// and turn on the External Memory Interface. I used enable(8, 0x0000, 1, 0)
// for my tests, (8 = 8 bit addressWidth, 0x0000 = only an upper sector,
// 1 = 1 wait-state(upper sector), 0 = 0 wait-state (lower sector)). If there's
// only an upper sector, you can omit the last parameter.
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////
// You can have two different wait-state settings if needed. (eg. Two
// hardware devices each having different timing specs). If only one wait
// state setting is needed use the default(0x0000). Otherwise entering a
// valid value creates an upper and a lower sector, each having it's own
// wait-state set with the enable() function. If the default is used there
// is only an upper sector. However, both "Upper" and "Lower" functions can
// still be used, as they will have the same effect.
////////////////////////////////////////////////////////////////////////////