Date: Fri, 27 Oct 95 13:32:33 JST
To: kagel AT ts1 DOT bloomberg DOT com
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu, kawakami AT mita DOT nel DOT co DOT jp
Subject: Re: .exe file format
From: kawakami AT mita DOT nel DOT co DOT jp (KAWAKAMI Akira)

In Message-ID <9510261159 DOT AA09561 AT quasar DOT bloomberg DOT com >
kagel AT quasar DOT bloomberg DOT com wrote:

>>    From: kawakami AT mita DOT nel DOT co DOT jp
>>    Date: Thu, 26 Oct 95 20:07:21 +0900
>> 
>>    In Message-Id: <173B73316E AT fs2 DOT mt DOT umist DOT ac DOT uk> 
>>    "A.Appleyard" <A DOT APPLEYARD AT fs2 DOT mt DOT umist DOT ac DOT uk> wrote: 
>>    >If a .COM file did start with `MZ' or `ZM', would that correspond with any
>>    >legal or likely PC instructions?
>> 
>>    `M' and `Z' are `dec bp' and `pop dx' in x86 instruction.  I have no
>>    idea to write a program which starts with these instructions.
>>    --------
>>    KAWAKAMI Akira <kawakami AT mita DOT nel DOT co DOT jp>
>>    NTT Electronics Technology Corporation, Japan.
>> 
>> If memory serves...  It does not matter to what instructions 'MZ' or 'ZM'
>> equate, .COM programs jump to address 100 to start and .EXEs start after the
>> .EXE header records (which include the 'MZ' string.  Those first few bytes, at
>> least, in a DOS/Windows executeable are never look at as instructions.
>> 
>> -- 
>> Art S. Kagel, kagel AT ts1 DOT bloomberg DOT com
>> 
>> Variety is the soul of pleasure.  --  Aphra Behn

Yes, you're right but for one exception.  .COM programs are loaded
address 100.  So *IF* a .COM program starting with `M' -- or whatever
else -- are loaded, the byte address 100 is the first byte of that
.COM file, isn't it?
--------
KAWAKAMI Akira <kawakami AT mita DOT nel DOT co DOT jp>
NTT Electronics Technology Corporation