diff --git a/src/cmd/dskres.s b/src/cmd/dskres.s
index ac432bb..1c08630 100644
--- a/src/cmd/dskres.s
+++ b/src/cmd/dskres.s
@@ -1,26 +1,32 @@
 " dskres
 
-   iof
-   hlt
-   dzm track
-   -640
+	" Copies the entire file system (except system image and
+	" swap area) from side 0 of the disk onto same location
+	" on side 1.
+	"
+	" I.e. copies the first 6400 blocks from side 0 to side 1.
+
+   iof			" disable interrupts
+   hlt			" halt the computer!
+   dzm track		" start copying from block address 0
+   -640			" transfer 640 chunks of 10 blocks each
    dac c1
 1:
-   lac track
+   lac track		" read chunk of blocks starting at block "track" on side 0
    jms dskrd0
 
-   lac track
+   lac track		" write chunk of blocks starting at block "track" on side 1
    jms dskwr1
 
-   lac track
+   lac track		" proceed to next chunk (of 10 blocks)
    tad d10
    dac track
-   isz c1
-   jmp 1b
+   isz c1		" increment chunks transferred, if there are chunks remaining
+   jmp 1b		" ...loop and transfer the next chunk
 
-   hlt
-   sys exit
+   hlt			" ...otherwise halt the computer!
+   sys exit		" call exit system call
 
-track: 0
-c1: 0
-d10: 10
\ No newline at end of file
+track: 0		" block address of chunk to transfer
+c1: 0			" number of chunks remaining
+d10: 10