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Borlands Tasm 4.1 generating faulty output problem

From	"R.Wieser" <address@not.available>
Newsgroups	comp.os.msdos.programmer
Subject	Borlands Tasm 4.1 generating faulty output problem
Date	2021-05-25 16:07 +0200
Organization	Aioe.org NNTP Server
Message-ID	<s8j0bu$pkn$1@gioia.aioe.org> (permalink)

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Hello all,

I'm using Borlands Tasm 4.1 and TLink 7.1.30.1 on XPsp3 in a CMD box, and 
have run in a situation where NTVDM throws an error because of an unknown 
opcode.

It looks like that it has nothing to do with my programming (jay !), but 
with either of the above programs.  Below are the relevant parts from the 
executable, the object and the list files.

The problem is the 0x00 injected at address 0x05D1 in the .EXE and address 
0x09AA in the.OBJ, but *not* the .LST file (at 0x05D1).  Among others it 
causes the JMP to be one byte short, pointing to the last byte of the 
command before the actual targetted command (causing the NTVDM to barf).

Notice that the second commandbyte at 0x05D3 in the .EXE does not match the 
one at 0x09AC in the .OBJ file (presumably because of the assemble-time 
fixup of the argument of the PUSH at line 1668 of the .LST file).

Remarkably, when I place a NOP (or any byte for that matter) just below the 
"jmp  @@CmdGetDir2" at line 1664 in the .LST file the problem fully 
disappears.

-- .EXE
162E:05C7 683412        PUSH 1234
162E:05CA 6A00          PUSH +00
162E:05CC E836FF        CALL 0505
162E:05CF EB49          JMP 061A
162E:05D1 00FF          ADD BH,BH       ;<--
162E:05D3 F4            HLT
162E:05D4 9D            POPF
162E:05D5 01E8          ADD AX,BP
162E:05D7 D0FA          SAR DL,1

-- .OBJ
15C7:09A0 683412        PUSH 1234
15C7:09A3 6A00          PUSH +00
15C7:09A5 E836FF        CALL 08DE
15C7:09A8 EB49          JMP 09F3
15C7:09AA 00FF          ADD BH,BH       ;<--
15C7:09AC 3696          XCHG AX,SI
15C7:09AE 01E8          ADD AX,BP
15C7:09B0 D0FA          SAR DL,1

-- .LST
1  1659     05C7  68 1234    PUSH  1234H
1  1660     05CA  6A 00     PUSH  gcCOM
1  1661     05CC  E8 FF36    CALL  CommWriteBlock
   1662     05CF  EB 49     jmp  @@CmdGetDir2
   1663
   1664      ;             <--
   1665
   1666      ;---------------
   1667     05D1    @@CmdGetDir1:
   1668       call  TTYHexWord,[gBlkBuf].BLK2FLE_wAttrib
1  1669     05D1  FF 36 0196r    PUSH  [gBlkBuf]. BLK2FLE_wAttrib
1  1670     05D5  E8 FAD0    CALL  TTYHexWord

The question: does anyone recognise it and knows how how/with what to fix 
it.  Likely an update of either or both of the above files ...

Regards,
Rudy Wieser

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Borlands Tasm 4.1 generating faulty output problem "R.Wieser" <address@not.available> - 2021-05-25 16:07 +0200

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