Here is small Tiny Lousy HexViewer that uses memory buffer (not memory mapped).
EDIT: 20110808 even smaller without RTL
EDIT: 20111015 fixed typo (TLHexView_WS_2.zip)
PS:
bcc 5.51 users can compile this with commands:
bcc32.exe -c -W TLHexView.c
ilink32.exe -M -aa -Tpe -c -V4.0 -Llib\PSDK NoCrt WinCRT1 TLHexView user32.lib, TLHexView.exe
; NoCrt startup code
; use WinMainCRTStartup as new starting point like MS linker do
; compile this with JWAsm.exe NorCrt.asm
.386p
.model flat, stdcall
extern WinMainCRTStartup : proc
public _start
.code
_start:
jmp WinMainCRTStartup
end _start