sys comments for rmes/smes calls, process table (user list) words

noticed "exit" call falls into "rmes" call!!!

src/sys/s3.s

@@ -1,7 +1,7 @@
 "** 01-s1.pdf page 14
 " s3
 
-	" search for user (process)
+	" search for user (process) table entry
 	" call:
 	"   jms searchu; worker_routine_addr
 	" worker called with copy of a process table entry in "lu"
@@ -113,36 +113,44 @@ badcal:				" bad (unimplemented) system call
    isz u.ulistp
    dzm u.ulistp i		" clear pid in process table
    jms swap			" find a new process to run
+	" exit falls into "rmes" !!!
 
+	" rmes system call
+	"   sys smes
+	" returns with message delivered, or error if process does not exit
+	" AC/ sending pid
+	" MQ/ message
 .rmes:
    jms awake
-   lac o100000
+   lac o100000			" mark this process to "not ready"
    tad u.ulistp i
    dac u.ulistp i
    law 2
    tad u.ulistp
-   dac 9f+t
+   dac 9f+t			" pointer to msg status in proc table
    -1
-   dac 9f+t i
-   jms swap
+   dac 9f+t i			" set to -1 (waiting for message)
+   jms swap			" switch processes
    law 2
    tad u.ulistp
    dac 9f+t
-   lac 9f+t i
-   cma
-   dac u.ac
-   dzm 9f+t i
+   lac 9f+t i			" get msg status word
+   cma				" complement (get sender pid)
+   dac u.ac			" return in user AC
+   dzm 9f+t i			" clear status word
    isz 9f+t
-   lac 9f+t i
-   dac u.mq
-   dzm 9f+t i
+   lac 9f+t i			" get message
+   dac u.mq			" return in user MQ
+   dzm 9f+t i			" clear message
    jmp sysexit
 t = t+1
 
 "** 01-s1.pdf page 16
 	" smes system call
 	" AC/ pid
+	" MQ/ message
 	"   sys smes
+	" returns with message delivered, or error if process does not exit
 .smes:
    lac u.ac			" get pid from user AC
    sna spa			" >0?
@@ -158,10 +166,10 @@ t = t+1
    sad u.ac			" match?
    skp				"  yes
    jmp 1b i			"   no
-   lac lu+2			" get mailbox
+   lac lu+2			" get mailbox status
    sad dm1			" -1?
    jmp 1f			"  yes
-   lac o100000			" no: increment process status
+   lac o100000			" no: bump our process status (to notready?)
    tad u.ulistp i
    dac u.ulistp i
    law 2
@@ -178,35 +186,36 @@ t = t+1
 1:
    -3
    tad 8
-   dac 9f+t
-   lac o700000
+   dac 9f+t			" pointer to dest process ulist entry
+   lac o700000			" complement process status? marks ready??
    tad 9f+t i
    dac 9f+t i
    isz 9f+t
-   isz 9f+t
-   lac u.pid
-   cma
-   dac 9f+t i
-   isz 9f+t
-   lac u.mq
-   dac 9f+t i
+   isz 9f+t			" point to mailbox word?
+   lac u.pid			" get our pid
+   cma				" complement
+   dac 9f+t i			" store in mailbox??
+   isz 9f+t			" advance to next word
+   lac u.mq			" get user MQ
+   dac 9f+t i			" save as message
    jmp okexit
 t = t+1
 
+	" wake up process hanging on rmes for current process??
 awake: 0
    jms searchu; 1f
    jmp awake i
 1: 0				" searchu worker
    lac u.pid			" get caller pid
-   sad lu+2			" match process table entry?
+   sad lu+2			" match mailbox status?
    skp				"  yes
    jmp 1b i			"   no, return
    -3
-   tad 8			" get pointer to pid in process table??
+   tad 8			" get pointer to process table entry
    dac 9f+t			" save in t0
 "** 01-s1.pdf page 17
-   lac o700000			" set high bits
-   tad 9f+t i
+   lac o700000
+   tad 9f+t i			" complement process status (mark ready)??
    dac 9f+t i
    jmp 1b i			" return from worker
 t = t+1