Int 21 - Comtrol Hostess I/isa Debugger - Get Segment For Control Program U
Int 21 Fn 00 - Dos 1+ - Terminate Program
Int 21 Fn 01 - Dos 1+ - Read Character From Standard Input, With Echo
Int 21 Fn 010F - Virus - "susan" - Installation Check
Int 21 Fn 02 - Dos 1+ - Write Character To Standard Output
Int 21 Fn 03 - Dos 1+ - Read Character From Stdaux
Int 21 Fn 04 - Dos 1+ - Write Character To Stdaux
Int 21 Fn 05 - Dos 1+ - Write Character To Printer
Int 21 Fn 06 - Dos 1+ - Direct Console Output
Int 21 Fn 06 - Dos 1+ - Direct Console Input
Int 21 Fn 07 - Dos 1+ - Direct Character Input, Without Echo
Int 21 Fn 08 - Dos 1+ - Character Input Without Echo
Int 21 Fn 09 - Dos 1+ - Write String To Standard Output
Int 21 Fn 0A - Dos 1+ - Buffered Input
Int 21 Fn 0A00 - Wced V1.6+ - Installation Check
Int 21 Fn 0B - Dos 1+ - Get Stdin Status
Int 21 Fn 0B56 - Virus - "perfume" - Installation Check
Int 21 Fn 0C - Dos 1+ - Flush Buffer And Read Standard Input
Int 21 Fn 0D - Dos 1+ - Disk Reset
Int 21 Fn 0D20 - Virus - "crazy Imp" - Installation Check
Int 21 Fn 0E - Dos 1+ - Select Default Drive
Int 21 Fn 0E U - Novell Dos 7 - Sdres V27.03 - Installation Check
Int 21 Fn 0E U - Novell Dos 7 - Sdres V27.03 - Clear ??? Flag
Int 21 Fn 0E U - Novell Dos 7 - Sdres V27.03 - Set ??? Flag
Int 21 Fn 0F - Dos 1+ - Open File Using Fcb
Int 21 Fn 10 - Dos 1+ - Close File Using Fcb
Int 21 Fn 11 - Dos 1+ - Find First Matching File Using Fcb
Int 21 Fn 12 - Dos 1+ - Find Next Matching File Using Fcb
Int 21 Fn 13 - Dos 1+ - Delete File Using Fcb
Int 21 Fn 14 - Dos 1+ - Sequential Read From Fcb File
Int 21 Fn 15 - Dos 1+ - Sequential Write To Fcb File
Int 21 Fn 16 - Dos 1+ - Create Or Truncate File Using Fcb
Int 21 Fn 17 - Dos 1+ - Rename File Using Fcb
Int 21 Fn 18 - Dos 1+ - Null Function For Cp/m Compatibility
Int 21 Fn 1812 - Virus - "tasha Yar" - Installation Check
Int 21 Fn 187F - Virus - "ds-3783" -installation Check
Int 21 Fn 18FF - Virus - "pathogen:smeg" - Installation Check
Int 21 Fn 19 - Dos 1+ - Get Current Default Drive
Int 21 Fn 1A - Dos 1+ - Set Disk Transfer Area Address
Int 21 Fn 1B - Dos 1+ - Get Allocation Information For Default Drive
Int 21 Fn 1C - Dos 1+ - Get Allocation Information For Specific Drive
Int 21 Fn 1D - Dos 1+ - Null Function For Cp/m Compatibility
Int 21 Fn 1E - Dos 1+ - Null Function For Cp/m Compatibility
Int 21 Fn 1F - Dos 1+ - Get Drive Parameter Block For Default Drive
Int 21 Fn 20 - Dos 1+ - Null Function For Cp/m Compatibility
Int 21 Fn 2080 - Virus - "new-year" - Installation Check
Int 21 Fn 21 - Dos 1+ - Read Random Record From Fcb File
Int 21 Fn 22 - Dos 1+ - Write Random Record To Fcb File
Int 21 Fn 23 - Dos 1+ - Get File Size For Fcb
Int 21 Fn 24 - Dos 1+ - Set Random Record Number For Fcb
Int 21 Fn 25 - Dos 1+ - Set Interrupt Vector
Int 21 Fn 2501 P - Phar Lap 386/dos-extender - Reset Dos Extender Data Stru
Int 21 Fn 2502 P - Phar Lap 386/dos-extender - Get Protected-mode Interrupt
Int 21 Fn 2503 P - Phar Lap 386/dos-extender - Get Real-mode Interrupt Vect
Int 21 Fn 2504 P - Phar Lap 386/dos-extender - Set Protected-mode Interrupt
Int 21 Fn 2505 P - Phar Lap 386/dos-extender - Set Real-mode Interrupt Vect
Int 21 Fn 2506 P - Phar Lap 386/dos-extender - Set Int To Always Gain Cntrl
Int 21 Fn 2507 P - Phar Lap 386/dos-extender - Set Real- & Protected-mode I
Int 21 Fn 2508 P - Phar Lap 386/dos-extender - Get Segment Linear Base Addr
Int 21 Fn 2509 P - Phar Lap 386/dos-extender - Convert Linear To Physical A
Int 21 Fn 2509 P - Flashtek X-32vm - Get System Segments And Selectors
Int 21 Fn 250A P - Phar Lap 386/dos-extender - Map Physical Memory At End O
Int 21 Fn 250C P - Phar Lap 386/dos-extender - Get Hardware Interrupt Vecto
Int 21 Fn 250D P - Phar Lap 386/dos-extender - Get Real-mode Link Informati
Int 21 Fn 250E P - Phar Lap 386/dos-extender - Call Real-mode Procedure
Int 21 Fn 250F P - Phar Lap 386/dos-extender - Convert Protected-mode Addre
Int 21 Fn 2510 P - Phar Lap 386/dos-extender - Call Real-mode Procedure, Re
Int 21 Fn 2511 P - Phar Lap 386/dos-extender - Issue Real-mode Interrupt
Int 21 Fn 2512 P - Phar Lap 386/dos-extender - Load Program For Debugging
Int 21 Fn 2513 P - Phar Lap 386/dos-extender - Alias Segment Descriptor
Int 21 Fn 2514 P - Phar Lap 386/dos-extender - Change Segment Attributes
Int 21 Fn 2515 P - Phar Lap 386/dos-extender - Get Segment Attributes
Int 21 Fn 2516 P - Phar Lap 386/dos-extender V2.2+ - Free All Memory Owned
Int 21 Fn 2517 P - Phar Lap 386/dos-extender V2.1c+ - Get Info On Dos Data
Int 21 Fn 2518 P - Phar Lap 386/dos-extender 2.1c+ - Specify Handler For Mo
Int 21 Fn 2519 P - Phar Lap 386/dos-extender Vmm - Get Additional Memory Er
Int 21 Fn 251A P - Phar Lap 386/dos-extender Vmm - Lock Pages In Memory
Int 21 Fn 251B P - Phar Lap 386/dos-extender Vmm - Unlock Pages
Int 21 Fn 251C P - Phar Lap 386/dos-extender Vmm V2.1c+ - Free Physical Mem
Int 21 Fn 251D OP - Phar Lap 386/dos-extender Vmm V2.1c - Read Page-table E
Int 21 Fn 251E OP - Phar Lap 386/dos-extender Vmm V2.1c - Write Page-table
Int 21 Fn 251F P - Phar Lap 386/dos-extender Vmm - Exhange Two Page-table E
Int 21 Fn 2520 P - Phar Lap 386/dos-extender Vmm - Get Memory Statistics
Int 21 Fn 2521 P - Phar Lap 386/dos-extender Vmm - Limit Program's Extended
Int 21 Fn 2522 P - Phar Lap 386/dos-ext Vmm V2.2+ - Specify Alternate Page-
Int 21 Fn 2523 P - Phar Lap 386/dos-ext Vmm V2.2+ - Specify Out-of-swap-spa
Int 21 Fn 2524 P - Phar Lap 386/dos-ext Vmm V2.2+ - Install Page-replacemen
Int 21 Fn 2525 P - Phar Lap 386/dos-extender Vmm - Limit Program's Convent'
Int 21 Fn 2526 P - Phar Lap 386/dos-extender - Get Configuration Informatio
Int 21 Fn 2527 P - Phar Lap 386/dos-extender Vmm - En/disable State Save On
Int 21 Fn 2528 P - Phar Lap 386/dos-extender Vmm - Read Registers After Ctr
Int 21 Fn 2529 P - Phar Lap 386/dos-extender - Load Flat Model .exp Or .rex
Int 21 Fn 252A P - Phar Lap 386/dos-extender Vmm - New Load Program For Deb
Int 21 Fn 252B Pu - Phar Lap 386/dos-extender - Create Unmapped Pages
Int 21 Fn 252B Pu - Phar Lap 386/dos-extender - Create Allocated Pages
Int 21 Fn 252B Pu - Phar Lap 386/dos-extender - Create Physical Device Page
Int 21 Fn 252B Pu - Phar Lap 386/dos-extender - Map Data File
Int 21 Fn 252B Pu - Phar Lap 386/dos-extender - Get Page Types
Int 21 Fn 252B P - Phar Lap 386/dos-extender - Virtual Memory Management -
Int 21 Fn 252B Pu - Phar Lap 386/dos-extender - Free Physical Pages
Int 21 Fn 252B P - Phar Lap 386/dos-extender V4.1 - Get Pagetable Entry/pag
Int 21 Fn 252B P - Phar Lap 386/dos-extender V4.1 - Set Pagetable Entry/pag
Int 21 Fn 252B P - Phar Lap 386/dos-extender V4.1+ - Map Data File At File
Int 21 Fn 252C P - Phar Lap 386/dos-ext Vmm V3.0 - Add Unmapped Pages At En
Int 21 Fn 252D P - Phar Lap 386/dos-extender Vmm V2.3+ - Close Vmm File Han
Int 21 Fn 252E P - Phar Lap 386/dos-extender Vmm V2.3+ - Get/set Vmm Parame
Int 21 Fn 252F P - Phar Lap 386/dos-ext Vmm V3.0 - Write Record To Vmm Page
Int 21 Fn 2530 P - Phar Lap 386/dos-ext Vmm V2.3+ - Set Size Of Buffer For
Int 21 Fn 2531 P - Phar Lap 386/dos-extender Vmm V3.0 - Read/write Ldt Desc
Int 21 Fn 2532 P - Phar Lap 386/dos-extender - Get Exception Handler Vector
Int 21 Fn 2533 P - Phar Lap 386/dos-extender - Set Exception Handler Vector
Int 21 Fn 2534 P - Phar Lap 386/dos-extender V3.0+ - Get Interrupt Flag
Int 21 Fn 2535 P - Phar Lap 386/dos-extender V3.0+ - Read/write System Regi
Int 21 Fn 2536 P - Phar Lap 386/dos-ext Vmm V3.0+ - Min/max Extended/conv M
Int 21 Fn 2537 P - Phar Lap 386/dos-ext Vmm V3.0 - Allocate Dos Memory Abov
Int 21 Fn 2538 P - Phar Lap 386/dos-ext Vmm V3.0 - Read Protmode Regs After
Int 21 Fn 2539 P - Phar Lap 386/dos-ext Vmm V3.0 - Get Offset Of .exp File
Int 21 Fn 253A P - Phar Lap 386/dos-extender V3.0+ - Install Mod. Seg Failu
Int 21 Fn 253B P - Phar Lap 386/dos-extender V3.0+ - Jump To Real Mode Code
Int 21 Fn 253C P - Phar Lap 386/dos-extender Vmm V3.0+ - Shrink 386|vmm Swa
Int 21 Fn 253D P - Phar Lap 386/dos-extender V4.0+ - Read/write Idt Descrip
Int 21 Fn 253F Pu - Phar Lap 386/dos-extender V6.0+ - Allocate Ldt Descript
Int 21 Fn 2540 Pu - Phar Lap 386/dos-extender V6.0+ - Force Alias Of Segmen
Int 21 Fn 2544 Pu - Phar Lap 386/dos-extender V6.0+ - Free Dll
Int 21 Fn 2545 Pu - Phar Lap 386/dos-extender V6.0+ - Get/set Procedure Add
Int 21 Fn 2546 Pu - Phar Lap 386/dos-extender V6.0+ - Get Module Handle
Int 21 Fn 25C0 P - Phar Lap 386/dos-extender - Allocate Ms-dos Memory Block
Int 21 Fn 25C1 P - Phar Lap 386/dos-extender - Release Ms-dos Memory Block
Int 21 Fn 25C2 P - Phar Lap 386/dos-extender - Modify Ms-dos Memory Block
Int 21 Fn 25C3 P - Phar Lap 386/dos-extender - Execute Program
Int 21 Fn 26 - Dos 1+ - Create New Program Segment Prefix
Int 21 Fn 27 - Dos 1+ - Random Block Read From Fcb File
Int 21 Fn 28 - Dos 1+ - Random Block Write To Fcb File
Int 21 Fn 29 - Dos 1+ - Parse Filename Into Fcb
Int 21 Fn 2A - Dos 1+ - Get System Date
Int 21 Fn Sect - Dos 1+ - Set System Date
Int 21 Fn 2B - Ai Architects - ??? - Installation Check
Int 21 Fn 2B - Super Pc-kwik V3.20+ - Installation Check
Int 21 Fn 2B - Desqview - Installation Check
Int 21 Fn 2B - Elres V1.1 - Installation Check
Int 21 Fn 2B00 - The Volkov Commander - Get Pointer To Left Panel Data Stru
Int 21 Fn 2B01 - The Volkov Commander - Get Pointer To Right Panel Data Str
Int 21 Fn 2B02 - The Volkov Commander - Get Pointer To Global Variables
Int 21 Fn 2B01 - Quarterdeck Dos-up.sys V2.00 - Installation Check
Int 21 Fn 2B01 - Tame V2.10+ - Installation Check
Int 21 Fn 2B16 - Virus - "maltese Amoeba" - Installation Check
Int 21 Fn 2B44 - Pcanywhere Iv/lan - Installation Check
Int 21 Fn 2B - Volkov Commander - Installation Check
Int 21 Fn 2B - Wdtsr.com - Installation Check
Int 21 Fn 2B - Bitfoss - Installation Check
Int 21 Fn 2B - Bitfossi - Installation Check
Int 21 Fn 2C - Dos 1+ - Get System Time
Int 21 Fn 2C - Virus - "anti Pode 2.0" - Installation Check
Int 21 Fn 2C00 - Skudo - Installation Check
Int 21 Fn 2C2C - Virus - "lockjaw/proto-t" - Installation Check
Int 21 Fn 2D - Dos 1+ - Set System Time
Int 21 Fn 2D01 - Pc-mix - Installation Check
Int 21 Fn 2E - Dos 1+ - Set Verify Flag
Int 21 Fn 2F - Dos 2+ - Get Disk Transfer Area Address
Int 21 Fn 30 - Dos 2+ - Get Dos Version
Int 21 Fn 30 - Phar Lap 386/dos-extender, Intel Code Builder - Installation
Int 21 Fn 30 - Virus - "possessed" - Installation Check
Int 21 Fn 30 - Virus - "andromeda-758" -installation Check
Int 21 Fn 3000 - Ctask 2.0+ - Installation Check
Int 21 Fn 3000 - Pc-mos/386 V3.0 - Installation Check/get Version
Int 21 Fn 3000 - Virus - "jackal" - Installation Check
Int 21 Fn 3022 - Stopprg V2.0 - Installation Check
Int 21 Fn 3030 - Virus - "imtc" -installation Check
Int 21 Fn 3032 - Virus - "uruguay" - Installation Check
Int 21 Fn 30F1 - Virus - "dutch-555"/"quit 1992" - Installation Check
Int 21 Fn 30FF - Desq??? - Installation Check
Int 21 Fn 31 - Dos 2+ - Terminate And Stay Resident
Int 21 Fn 32 - Dos 2+ - Get Dos Drive Parameter Block For Specific Drive
Int 21 Fn 33 - Dos 2+ - Extended Break Checking
Int 21 Fn 3302 - Dos 3.x+ Internal - Get And Set Extended Control-break Che
Int 21 Fn 3303 - Dos 4.0+ - Unused
Int 21 Fn 3304 - Dos 4.0+ - Unused
Int 21 Fn 3305 - Dos 4.0+ - Get Boot Drive
Int 21 Fn 3306 - Dos 5+ - Get True Version Number
Int 21 Fn 3306 - Cbis Network - Network Redirector - ???
Int 21 Fn 330F - Virus - "burghofer" - Installation Check
Int 21 Fn 3341 - Diet Disk V1.0 - Installation Check
Int 21 Fn 33DA - Virus - "coffeeshop" - Installation Check
Int 21 Fn 33E0 - Virus - "oropax" - Installation Check
Int 21 Fn 34 - Dos 2+ - Get Address Of Indos Flag
Int 21 Fn 35 - Dos 2+ - Get Interrupt Vector
Int 21 Fn 3501 P - Flashtek X-32vm - Allocate Protected-mode Selector
Int 21 Fn 3502 P - Flashtek X-32vm - Deallocate Protected-mode Selector
Int 21 Fn 3503 P - Flashtek X-32vm - Set Selector Base Address
Int 21 Fn 3504 P - Flashtek X-32vm - Get Selector Base Address
Int 21 Fn 3505 P - Flashtek X-32vm - Set Selector Limit
Int 21 Fn 350A P - Flashtek X-32vm - Physical Address Mapping
Int 21 Fn 350B P - Flashtek X-32vm - Update And Return Available Free Memor
Int 21 Fn 350C P - Flashtek X-32vm - Allocate A Block Of Memory
Int 21 Fn 350D P - Flashtek X-32vm - Reserve Block Of Memory For 32-bit Sta
Int 21 Fn 357F - Virus - "agiplan"/"month 4-6" - Installation Check
Int 21 Fn 36 - Dos 2+ - Get Free Disk Space
Int 21 Fn 3700 - Dos 2+ - "switchar" - Get Switch Character
Int 21 Fn 3701 - Dos 2+ - "switchar" - Set Switch Character
Int 21 Fn 37 - Dos 2.x And 3.3+ Only - "availdev" - Specify \dev\ Prefix Us