Interrupt 49h   Non-keyboard Scan Code Translation Table Address (PCjr) 
(0:0124h)       This interrupt is used for operation of non-keyboard devices 
		on the PCjr, such as the Keystronic Numeric Keypad. 
		This interrupt has the address of a table used to translate 
		non-keyboard scancodes (greater than 85 excepting 255). This 
		interrupt can be revectored by a user application. IBM 
		recommends that the default table be stored at the beginning 
		of an application that required revectoring this interrupt,  
		and that the default table be restored when the application 
		terminates. (not initialized on PC or AT) 
 
		The PCjr BIOS can interpret scancodes other than those  
		generated by the keyboard to allow for expansion. The keyboard 
		generates scancodes from 01h to 055h, including 0FFh. Any  
		scancodes above 55h (56h through 7Eh for make codes and 0D6h 
		through 0FEh for break codes) are processed in the following 
		manner: 
		1) if the incoming make code falls within the range of the 
                   translate table whose address is pointed to by int 49h, it
		   is translated into the corresponding scancode. Any incoming 
		   break codes above 0D5h are ignored. 
		2) if the new translated scancode ius less and 56h, it is 
		   processed by the BIOS as a keyboard scancode and the same 
		   data is placed in the BIOS keyboard buffer. 
		3) if the translated scancode is higher than 55h or the 
		   incoming scancode is outside the range of the translate 
		   table, 40h is added creating a new extended scancode. The 
		   extended scancode is placed in the BIOS keyboard buffer with  
		   the character code of 00h (NUL). This utilitizes the range 
		   of 96h through 0BEh for scancodes 56h through 7Eh. 
 
		The default translate-table maps scancodes 56h through 6Ah to 
		existing keyboard values. Codes 6Bh theough 0BEh are mapped (by 
		adding 40h) to extended codes 0ABh through 0FEh since they are 
		outside the range of the default translate table. 
 
		The format of the translate table is: 
		0       length - the number of nonkeyboard scancodes that are 
			mapped within the table (from 1 to n) 
		1 to n  word  high byte 00h (NUL) byte scancode with low order 
			byte representing the scancode mapped values relative 
			to their input values within the range of 56h through 
			7Eh 
 
		With this layout, all keyboard scancodes can be intercepted 
                through Int\09 and and nonkeyboard scancodes can be
                intercepted through Int\48.

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