From: admin@nospicedham.127.0.0.1   
      
   On Mon, 26 Dec 2022 13:05:38 +0100   
   wolfgang kern  wrote:   
      
   > On 26/12/2022 12:08, Jean pierneef wrote:   
   > > On Monday, December 26, 2022 at 11:33:44 AM UTC+2, Jean pierneef wrote:   
   > >> For the purpose of getting to grips with debug.exe on MSDOS 6.22 I have   
   the following code example:   
   > >>   
   > >> .model tiny   
   > >> .data   
   > >> msg DB 'test string',0   
   > >> .code   
   > >> start:   
   > >> mov al,msg   
   > >> end start   
   > >>   
   > >> When I compile it with tasm /zi t.asm and link it with tlink t I get the   
   following behaviour in debug.exe:   
   > >>   
   > >> When pressing 'r' to show registers and next command, I get:   
   > >>   
   > >> mov al,[0008] as the next instruction to execute.   
   > >>   
   > >> I was expecting the memory location of 'test string' to thus be at   
   ds:0008 but when I do:   
   > >>   
   > >> d ds:0108   
   > >>   
   > >> I find 'test string' there instead (and garbage at ds:0008).   
   > >>   
   > >> Can somebody please explain why 0100h is 'subtracted' from 0108h when I   
   do the 'r' command in debug.exe ?   
      
      
   I don't use masm; but if coding a .com I always start with:   
      
   org 0x100   
      
   > >   
   > > I have tried this on an MSDOS 6.22 running in Virtual Box (tasm v2.0,   
   unknown debug.exe version) as well as on Doxbox (tasm 2.51, debug.exe 1.25   
   which I presume comes from some open source project).   
   > >   
   > > I do not understand why "test string" is at location ds:0108h in memory,   
   but why debug says it wants to mov 0008 into the al register. Why the   
   discrepancy ?   
   >   
   > MOV AL,msg   ;loads the low byte of the ADDRESS 0108 into AL   
   > MOV AL,[msg] ;loads the content of this address   
   >   
   > I don't know Tasm, it may need a keyword (ptr?) instead of brackets   
      
      
   Masm needs   
      
   mov al,offset msg   
      
   IIRC.   
      
   --   
   Bah, and indeed Humbug.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)