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File Reading AH=3Fh, int 21h under DPMI not working (Developers)

posted by x86Novice, 17.03.2013, 01:14

Hello Everyone,
Sorry if this is an old age problem, searched many threads but unable to find anything related. My work environment is running MS-DOS 7, NASM (Ver 2.10.07) & HDPMI32 (ver 3.17) , having problem with loading a file's content to a buffer above 1MB, i.e
.
.
.
mov AH, 3Fh ;Read from file
mov BX, word [DS:FileHandle] ;File successfully Opened prior to this
mov ECX, 1000h ;Read 4096 Bytes from File
mov EDX, 300000h ;Buffer to store 1000h bytes to.
int 21h
.
.

Compiled Ok but hangs when executed with HDPMI32 loaded or otherwise.

I thought HDPMI32 would somehow intercept int 21h/AH=3F in protected mode and accept 32bit addressing unlike its 16bit counterpart ?
Would appreciate any suggestions, thanks for reading.

NOTE: Also tried other DPMIs to no avail.

Complete thread:

• File Reading AH=3Fh, int 21h under DPMI not working - x86Novice, 17.03.2013, 01:14 (Developers)
  • File Reading AH=3Fh, int 21h under DPMI not working - Japheth, 17.03.2013, 02:45
  • File Reading AH=$3F, INT $21 under DPMI | True DPMI - DOS386, 27.03.2013, 09:01