Category : Assembly Language Source Code
Archive   : PROTEC.ZIP
Filename : README.TXT

README.TXT

PROTECTED MODE TUTORIAL: ENTER PROTECTED MODE - EXIT TO REAL MODE EDMOD.COM
- RETURN TO PROTECTED MODE - FREEWARE
----------------------------------------------------------------------------

September 11, 1993

author :
R. Richardson, Drawer 1065, Chautauqua, NY 14722 phone: (716) 753-2654

history:
The Intel 80286 microprocessor introduced protected mode operation a number of
years ago that could directly address 16 megabytes of memory. The later Intel
80386, 80486 and Pentium microprocessors expanded the protected mode address-
ing capability to more than 4 gigabytes of memory.

The enclosed program, EN.EXE for Intel 80386, 80486 & Pentium microprocessors
is a tutorial with fully commented assembly language source code that
illustrates how to enter protected mode (12+ help pages), exit to the real
mode's EDMOD.COM program (edit/modify any/all ram memory + KISS disassemble), and return to protected mode with nothing changed (you may type in up to 19 lines of text if desired).

unique feature:
EN.EXE's source code is written in assembler, not C++ which most all protected
mode programs extant today use. As such, it runs faster than if written in
C++, occupies less memory than if written in C++, and serves as an excellent
tutorial for those wishing to learn the real ins and outs of protected mode
programming which is hidden from the users of C++.

installation:
The zipped file PROTEC.ZIP contains all the files used in the tutorial. It
must be unzipped to C:\PROTECT and contains less than 350k bytes. The program
EN.EXE must be run WITHOUT protected mode installed; i.e., no Windows, no QEMM386, no EMM386, etc.

INSTALL.BAT will rename your CONFIG.SYS file CONFIG.ORG and rename your AUTOEXEC.BAT file AUTOEXEC.ORG. It will then install the CONFIG.SYS and AUTOEXEC.BAT in C:\PROTECT in the root directory of C:\.

NOTE: UNINSTAL.BAT will restore your CONFIG.SYS and AUTOEXEC.BAT files in the root directory of C:\.

After installation, INSTALL.BAT asks you to reboot.
(please press the Ctrl, Alt, Del keys).

Please read the files EN.DOC and EDMOD.DOC files in C:\PROTECT that complement
EN.EXE's 12 help pages.

If you wish to modify and reassemble the souce code EN.ASM using ASM.BAT, the
program expects that Microsoft's Macro Assembler 6.0 + ML.ERR + LINK.EXE to be
in C:\MASM or C:\MASM\INCLUDE or C:\MASM\BINB or C:\PROTECT.

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