Interrupt 15h  Cassette I/O (or "System Services" on PS/2)
(0:0054h)
Function	Description				Model
----------	--------------------------------------- -----------------------
Int\15f\00	Turn Cassette Motor On			(PC, PCjr only) 
Int\15f\01	Turn Cassette Motor Off			(PC, PCjr only) 
Int\15f\02	Read Blocks From Cassette		(PC, PCjr only) 
Int\15f\03	Write Data Blocks to Cassette		(PC, PCjr only) 
Int\15f\0F	ESDI Format Unit Periodic Interrupt 	(PS/2 50, 60, 80) 
Int\15f\10	TopView API Function Calls		(TopView)
Int\15f\11	Topview commands 			(TopView)
Int\15f\20	PRINT.COM  (DOS internal)		(AT, XT-286, PS/2 50+) 
Int\15f\21	Power-On Self Test (POST) Error Log	(PS/2 50+) 
Int\15f\40	Read/Modify Profiles			(Convertible) 
Int\15f\41	Wait On External Event			(Convertible)  
Int\15f\42	Request System Power Off		(Convertible) 
Int\15f\43	Read System Status			(Convertible) 
Int\15f\44	(De)activate Internal Modem Power	(Convertible) 
Int\15f\4F	Keyboard Intercept			(except PC, PCjr, & XT)
Int\15f\80	Device Open				(AT, XT/286, PS/2) 
Int\15f\81	Device Close				(AT, XT/286, PS/2) 
Int\15f\82	Program Termination			(AT, XT/286, PS/2) 
Int\15f\83	Event Wait				(AT, XT/286, Convert, PS/2)
Int\15f\84	Read Joystick Input Settings		(AT, XT/286, PS/2) 
Int\15f\85	System Request (SysReq) Key Pressed	(except PC, PCjr, XT) 
Int\15f\86	Elapsed Time Wait			(except PC, PCjr, XT)
Int\15f\87	Extended Memory Block Move		(286/386 machines only)
Int\15f\88	Extended Memory Size Determine		(AT, XT/286, PS/2)
Int\15f\89	Switch Processor to Protected Mode	(AT, XT/286, PS/2)  
Int\15f\90	Device Busy Loop			(except PC, PCjr, XT)  
Int\15f\91	Set Flag and Complete Interrupt		(except PC, PCjr, XT) 
Int\15f\C0	Get System Configuration		(XT/10FEB86+, Convert)
Int\15f\C1	System-Extended BIOS Data-Area Segment	(PS/2) 
Int\15f\C2	Pointing Device BIOS Interface		(DesQview 2.x)  (PS/2)
Int\15f\C3	Enable/Disable Watchdog Timeout		(PS/2 50+) 
Int\15f\C4	Programmable Option Select		(PS/2 50+) 
Int\15f\DE	DesQview Services			(DesQview)