'Debug' usage in disk editting

I have the following debug script that I use. I wish to understand it to make changes to it. I am familiar with debug. But I can't understand the "e ds:0610 command...particularly the 'ds' part. Is it assembeler code? Similarly I have lack understanding of "rf", "nz", and "zr". Can you please get me started or point to a resource.

Thanks,
Right

g 0b2a
e ds:0610
04
e ds:0611
9c
e ds:0612
63
p
f ds:05c5 05ff 20
e ds:0613
0d
e ds:0614
0a
g 030d
t
g 0054
rf
nz
g 019d
rf
zr
g 01cd
rf
zr
g 0225
rf
zr
g
q

Here's a quick rundown:

Quote:

g 0b2a

Run the program at "0b2a" (g=go)

Quote:

e ds:0610
04

Enter "04" into the "ds" register at memory address "0610"

Quote:

e ds:0611
9c

Enter "9c" into the "ds" register at memory address "0611"

Quote:

e ds:0612
63

Enter "63" into the "ds" register at memory address "0612"

Quote:

p

Proceed

Quote:

f ds:05c5 05ff 20

Fill the "ds" register, from "05c5" through "05ff" with "20"'s

Quote:

e ds:0613
0d

Enter "0d" into the "ds" register at memory address "0613"

Quote:

e ds:0614
0a

Enter "0a" into the "ds" register at memory address "0610"

Quote:

g 030d

Run the program at "030d"

Quote:

t

Trace. (When used without parameters, t begins tracing at the address specified by the program's CS:IP registers).

Quote:

g 0054

Run the program at "0054"

Quote:

rf
nz

"nz" clears flag "Zero" in "f"

Quote:

g 019d

Run the program at "019d"

Quote:

rf
zr

"zr" sets flag "Zero" in "f"

Quote:

g 01cd

Run the program at "01cd"

Quote:

rf
zr

"zr" sets flag "Zero" in "f"

Quote:

g 0225

Run the program at "0225"

Quote:

rf
zr

"zr" sets flag "Zero" in "f"

Quote:

g

g=go

Quote:

q

q=quit

--

And a few related links:

Debug
http://www.microsoft.com/technet/arc...dos/comm2.mspx

Debug
http://www.microsoft.com/resources/d...-us/debug.mspx

Debug subcommands
http://www.microsoft.com/resources/d...g_subcmds.mspx

DEBUG Tutorial
http://www.armory.com/~rstevew/Publi...ug-manual.html

SpywareDR,

Thanks a million!

Qamar

You're welcome. :)