tools/as7: added syscalls chmod and chown, added auto-increment

locations, fixed a bug in character input, added several EAE
instructions. We now have cp.s, chmod.s and chown.s working.

src/cmd/chrm.s

@@ -1,41 +1,46 @@
-" chrm
+" chrm: chrm dir file [file file ...]
+"
+" chdir into the named directory and unlink the files that are in there
+"
+" The code depends on a "dd" directory existing which holds the named dir
 
-   lac 017777
-   tad d5
-   dac 1f
-   dac 2f
-   lac 017777 i
+   lac 017777			" Go to the argc
+   tad d5			" Skip past the argc and argv[0]
+   dac 1f			" Save argv[1] in the chdir arg below
+   dac 2f			" and in the unlink as well? Yes, we skip it
+   lac 017777 i			" How many arguments do we have?
    sad d4
-   sys exit
-   tad dm4
-   dac 017777 i
-   sys chdir; dd
-   sys chdir; 1;0
+     sys exit			" None, so exit
+   tad dm4			" Subtract 1
+   dac 017777 i			" and save in the argc
+
+   sys chdir; dd		" chdir to dd
+   sys chdir; 1;0		" and then into the first argument
 1:
-   lac 017777 i
+   lac 017777 i			" Any arguments left?
    sad d4
-   sys exit
-   tad dm4
+     sys exit			" No, exit the program
+   tad dm4			" Subtract 4 from the argc and update it
    dac 017777 i
-   lac 2f
+   lac 2f			" Move up to the next filename
    tad d4
-   dac 2f
-   sys unlink; 2:0
+   dac 2f			" and save it in the unlink arg
+   sys unlink; 2:0		" Unlink the file
    sma
-   jmp 1b
-   lac 2b
+     jmp 1b			" Loop back if the unlink was OK, or issue err
+   lac 2b			" Copy the filename pointer below
    dac 2f
-   lac d1
+   lac d1			" Write the filename on stdout
    sys write; 2:0; 4
    lac d1
-   sys write; 1f; 2
-   jmp 1b
-1:
-   040077;012000
+   sys write; 1f; 2		" Write " ?\n" on stdout
+   jmp 1b			" and loop back
 
+1:
+   040077;012000		" String literal " ?\n"
 dd:
-   <dd>;040040;040040;040040
+   <dd>;040040;040040;040040	" Filename dd
 d1: 1
 d4: 4
 d5: 5
-dm4: -4
+dm4: -4