NOTE: All macros that are part of SYS do not require DS to be the program Data Segment. These macros general low level DOS or BIOS calls. These macros can be used before library initialization and do not require DS to equal CS.
Some basic DOS stuff:
| GetEnvSeg | Return the segment of environment table. |
| GetEnvTable | Return a pointer to environment variable table. |
| GetEnvKey | Return a pointer to a variable in env table. |
| GetEnvVal | Return a pointer to the value of a varible in env table. |
| GetExecName | Return a pointer to the executable's file name. |
| GetExtendedBreak | Return the state of extended break checking. |
| GetSwitchChar | Return the command line switch character. |
| SetExtendedBreak | Change the state of extended break checking. |
| SetSwitchChar | Change the command line switch character. |
| GetSysDate | Get the current system date. |
| GetSysTime | Get the current system time. |
| GetCmdLine | Get command line parameter string. |
| CmdLineParser | Command line parameter string parser. |
| CmdLineOption | Command line parser option table entry. |
Miscellaneous stuff:
| Random | Generate a sort-of random number. |
| PtrToInt | Convert a pointer to a 32-bit integer value. |
| IntToPtr | Convert a 32-bit integer value to a pointer. |
| FlattenPtr | Reduce the offset of a pointer. |