The debugger defines a number of symbols which have special meaning.  These
symbols are used to refer to the computer's registers and other special
variables.

General Purpose Registers
     eax, ax, al, ah, ebx, bx, bl, bh, ecx, cx, cl, ch, edx, dx, dl, dh

Index Registers
     esi, si, edi, di

Base Registers
     esp, sp, ebp, bp

Instruction Pointer
     eip, ip

Segmentation Registers
     cs, ds, es, fs, gs, ss

Flags Registers
     fl, fl.o, fl.d, fl.i, fl.s, fl.z, fl.a, fl.p, fl.c, efl, efl.o, efl.d,
    efl.i, efl.s, efl.z, efl.a, efl.p, efl.c

8087 Registers
     st0, st1, st2, st3, st4, st5, st6, st7

8087 Control Word
     cw, cw.ic, cw.rc, cw.pc, cw.iem, cw.pm, cw.um, cw.om, cw.zm, cw.dm,
    cw.im

8087 Status Word
     sw, sw.b, sw.c3, sw.st, sw.c2, sw.c1, sw.c0, sw.es, sw.sf, sw.pe,
    sw.ue, sw.oe, sw.ze, sw.de, sw.ie

Miscellaneous Variables
     dbg$32, dbg$bottom, dbg$bp, dbg$code, dbg$cpu, dbg$ctid, dbg$data,
    dbg$etid, dbg$fpu, dbg$ip, dbg$left, dbg$monitor, dbg$os, dbg$pid,
    dbg$psp, dbg$radix, dbg$remote, dbg$right, dbg$sp, dbg$top, dbg$nil,
    dbg$src, dbg$loaded

The debugger permits the manipulation of register contents and special
debugger variables (e.g., dbg$32) using any of the operators described in
this chapter.  By default, these predefined names are accessed just like any
other variables defined by the user or the application.  Should the
situation ever arise where the application defines a variable whose name
conflicts with that of one of these debugger variables, the module specifier
_dbg may be used to resolve the ambiguity.  For example, if the application
defines a variable called cs then _dbg@cs can be specified to resolve the
ambiguity.  The "_dbg@" prefix indicates that we are referring to a debugger
defined symbol rather than an application defined symbol.  See
Predefined Symbols.