Int D4  - IBM ROM BASIC - Used While In Interpreter
 Int D4  - Stsc Apl*plus/pc - May Be Used In Future Releases
 Int D4 Fn 00  O - PC-mos/386 V5.01 - Obsolete Functions
 Int D4 Fn 02  - PC-mos/386 V3.0+ - Get System Control Block Pointer
 Int D4 Fn 03  - PC-mos/386 V5.01 - Get/set Extended Directory Information
 Int D4 Fn 04  - PC-mos/386 V3.0+ - Get Task Control Block
 Int D4 Fn 07  - PC-mos/386 V3.0+ - Wait For Event
 Int D4 Fn 10  - PC-mos/386 V3.0+ - Enter/leave Native 386 Execution Mode
 Int D4 Fn 11  - PC-mos/386 V3.0+ - Allocate Native Mode Memory Block
 Int D4 Fn 12  - PC-mos/386 V3.0+ - Free Native Mode Memory Block
 Int D4 Fn 13  - PC-mos/386 V5.01 - Get Alias For Selector (native Mode Only)
 Int D4 Fn 16  - PC-mos/386 V5.01 - Set/clear IRQ Reservation
 Int D4 Fn 19  - PC-mos/386 V5.01 - Get Task Id
 Int D4 Fn 1A  - PC-mos/386 V5.01 - Get/set Task Priority
 Int D4 Fn 1B  - PC-mos/386 V5.01 - Get/set Time Slice
 Int D4 Fn 1C  - PC-mos/386 V5.01 - Get/set Keyboard Mode
 Int D4 Fn 1D  - PC-mos/386 V5.01 - Get Current Program Name
 Int D4 Fn 1E  - PC-mos/386 V5.01 - Get Current Username And Security Class
 Int D4 Fn 1F  - PC-mos/386 V5.01 - Get Task Partition Information
 Int D4 Fn 20  - PC-mos/386 V5.01 - Get Port And Baudrate Information
 Int D4 Fn 21  - PC-mos/386 V5.01 - Remove A Task
 Int D4 Fn 22  - PC-mos/386 V5.01 - Add A Task To The System
 Int D4 Fn 23  - PC-mos/386 V5.01 - Change Terminal Driver
 Int D4 Fn 24  U - PC-mos/386 V5.01 - Get Operating System Serial Number
 Int D4 Fn 25  - PC-mos/386 V5.01 - Identify Load Address Of Device Driver Lo
 Int D4 Fn 26  - PC-mos/386 V5.01 - Get System Control Block Segment/selector
 Int D4 Fn 27  - PC-mos/386 V5.01 - Get Task Control Block Segment/selector
 Int D4 Fn 28  - PC-mos/386 V5.01 - Get Control Block Data From Scb Or Tcb
 Int D4 Fn 29  - PC-mos/386 V5.01 - Write Control Block Data Into Scb Or Tcb
 Int D4 Fn 2A  - PC-mos/386 V5.01 - Swap Control Block Data Of Scb Or Tcb
 Int D4 Fn 2C  - PC-mos/386 V5.01 - Get/set Spooler Parameters
 Int D4 Fn 2D  - PC-mos/386 V5.01 - Get Maximum Task Size