Assembly Language Help (alang.hlp) (Table of Contents; Topic list)
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Interrupt 21h, System Functions
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     Interrupt 21h──System Functions
 
     Function     Name
 
     25h          Set Interrupt Vector
     30h          Get MS-DOS Version Number
     33h          Get or Set Break Flag
     34h          Get Address of InDOS Flag
     35h          Get Interrupt Vector
     38h          Get or Set Country Information
     44h          IOCTL (I/O Control)
     50h          Set Program Segment Prefix (PSP) Address
     51h          Get Program Segment Prefix (PSP) Address
     59h          Get Extended Error Information
     5Eh          Get Machine Name, Get or Set Printer Setup
     5Fh          Device Reallocation
     63h          Get Lead Byte Table
     65h          Get Extended Country Information
     66h          Get or Set Code Page
     5D0Ah        Set Extended Error Information
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