Device is PIC24FJ64GA004 44 pin TQFP device.

 [RA0]	x 
 [RA1] 	Potentiometer (ADC in)
 [RA2]  {XTAL}
 [RA3]	{XTAL}
 [RA4]	Stepper Pulse
 [RA7]	Stepper Direction
 [RA8]	Steam Valve (Solenoid)
 [RA9]	x
 [RA10]	Chart Recorder Enable

 [RB0]	{PGED1}
 [RB1]	{PGEC1}
 [RB2]	Alarm
 [RB3]  Bubble in
 [RB4]	PWM fan out / Water solenoid
 [RB5]	PWM 4-20mA chart recorder out
 [RB6]	Rx (USB)
 [RB7]	Tx (USB)
 [RB8]	SCL (I2C)
 [RB9]	SDA (I2C)
 [RB10]	One Wire (Ow)
 [RB11]	MISO	
 [RB12]	SS
 [RB13]	MOSI
 [RB14]	SCK
 [RB15]	Card Detect

 [RC0]	Rx (printer)
 [RC1]	Tx (printer)
 [RC2]	x
 [RC3]	x
 [RC4]	x
 [RC5]	x
 [RC6]	x
 [RC7]	x

Daughter Board

 [RC8] Interrupt (active low)
 [RC9] Enable

In addition to the above, the daughter board has SDA and SCL (I2C) lines.