Date: Wed, 28 Apr 1999 10:23:30 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To: Johan Henriksson <johan DOT he AT telia DOT com>
cc: djgpp AT delorie DOT com
Subject: Re: Writing an OS
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On Sun, 27 Apr 1997, Johan Henriksson wrote:

> But you're right: Without any
> DOS-calls, it would be possible. Sadly, printf() use them...

DOS (and BIOS) calls are only one problem; there are others.  For 
example, some library functions use fixed absolute addresses in 
conventional memory to access BIOS data area, write the screen, etc.  
Other functions assume that certain hardware interrupts are hooked in a 
particular way that's only true under DOS/DPMI.  Etc. etc.--the list of 
system dependencies goes on and on...  Even the startup code won't run 
without DOS underneath.