masm 5.10 as in DDK
switch = "/"
a  Alphabetize segments
c  Generate cross-reference
d  Generate pass 1 listing
D  Define symbol
e  Emulate floating point instructions and IEEE format
I  Search directory for include files
l  Generate listing, a-list all
M  Preserve case of labels: l-All, x-Globals, u-Uppercase Globals
n  Suppress symbol tables in listing
p  Check for pure code
s  Order segments sequentially
t  Suppress messages for successful assembly
v  Display extra source statistics
w  Set warning level: 0-None, 1-Serious, 2-Advisory
X  List false conditionals
z  Display source line for each error message
Zi  Generate symbolic information for CodeView
Zd  Generate line-number information
