48 lines
2.3 KiB
Plaintext
48 lines
2.3 KiB
Plaintext
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DEFINITION MODULE DOSMemory;
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(*
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Interface to the DOS memory allocation routines ( DOSCALL 48H, 49H, 4AH ).
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The blocks are linked to the Modula-2 RunTime Support, thus they are known
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by the system and dumped in case of error.
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*)
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FROM SYSTEM IMPORT ADDRESS;
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EXPORT QUALIFIED DOSAlloc, DOSDeAlloc, DOSAvail, DOSSetSize, DOSGetMaxSize;
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PROCEDURE DOSAlloc( VAR a: ADDRESS; paraSize: CARDINAL );
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(* Allocates a block of paraSize paragraphs : *)
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(* a is the address of the block returned or NIL if the size *)
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(* is not available or an error occured *)
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PROCEDURE DOSDeAlloc( VAR a: ADDRESS; paraSize: CARDINAL );
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(* DeAllocates a block previously allocated with DOSAlloc. The *)
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(* paraSize passed must be the size given for allocate or setsize *)
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(* a is set to the NIL value if DeAlloc succeds, not modified *)
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(* an error occured. *)
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(* NOTE: the address passed MUST BE the address returned by *)
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(* DOSAlloc *)
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PROCEDURE DOSAvail(): CARDINAL;
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(* Function that returns the size ( in paragraphs ) of the largest *)
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(* space available. *)
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PROCEDURE DOSSetSize( a: ADDRESS; paraSize: CARDINAL; VAR errorCode: CARDINAL );
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(* Sets the size of the block given to the new size given in *)
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(* paraSize. The returned errorCode is : *)
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(* 0 : No Error *)
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(* 7 : memory control block destroyed *)
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(* 8 : insufficient memory *)
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(* 9 : incorrect block address *)
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(* NOTE: the address passed MUST BE the address returned by *)
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(* DOSAlloc *)
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PROCEDURE DOSGetMaxSize( a: ADDRESS ): CARDINAL;
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(* Gets the maximal paragraph size to which the block given as *)
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(* parameter can be extended *)
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(* NOTE: the address passed MUST BE the address returned by *)
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(* DOSAlloc *)
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END DOSMemory.
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