From c65a5587fb2e89d1e048a3e9be9fd15bf07a3eba Mon Sep 17 00:00:00 2001
From: Warren Toomey <wkt@tuhs.org>
Date: Wed, 9 Mar 2016 06:45:44 +1000
Subject: [PATCH] Comments to kernel files by Phil.

---
 src/sys/s1.s | 10 +++++-----
 src/sys/s2.s |  2 +-
 src/sys/s8.s |  7 +++++--
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/sys/s1.s b/src/sys/s1.s
index f50088c..6b71282 100644
--- a/src/sys/s1.s
+++ b/src/sys/s1.s
@@ -86,7 +86,7 @@ swap: 0
    jms lookfor; 1 " in/ready
       skp
    jmp 1b			" loop until a process becomes ready
-   dzm maxquant			" here with in/ready (self?)
+   dzm maxquant			" in/ready (self?): come back next tick!
    jmp 3f
 1:				" here with out/ready process
    dac 9f+t			" save process pointer (swapped out) in t0
@@ -97,7 +97,7 @@ swap: 0
    jmp 2f
 1:
    lac swap
-   dac u.swapret		" return to scheduler when swapped back
+   dac u.swapret		" return to caller when swapped back
    iof
    lac o200000			" change status to swapped out
    tad u.ulistp i
@@ -105,13 +105,13 @@ swap: 0
    ion
    jms dskswap; 07000		" swap process out
    lac u.dspbuf
-   sna
-   jmp 2f
+   sna				" process using display??
+   jmp 2f			"  no
    law dspbuf
    jms movdsp
 2:
    iof				" disable interrupts
-   lac o600000			" change status (1->7?)
+   lac o600000			" change status (1->7?????)
    tad 9f+t i
    dac 9f+t i
    ion				" enable interrupts
diff --git a/src/sys/s2.s b/src/sys/s2.s
index 4006ed5..64d6f93 100644
--- a/src/sys/s2.s
+++ b/src/sys/s2.s
@@ -284,7 +284,7 @@ open1:				" common exit for open/creat
    jmp 1f			"  no
    iof				" yes: disable interrupts
    lac ii			" get i number
-   tad swr			" get read routine table addr
+   tad swr			" add to base instruction
    dac .+1
    jmp .. i			" dispatch to read routine
 1:
diff --git a/src/sys/s8.s b/src/sys/s8.s
index afce88c..6b88276 100644
--- a/src/sys/s8.s
+++ b/src/sys/s8.s
@@ -175,8 +175,11 @@ sysdata:			" system data 64 words saved to disk
 	"	4: out/notready??
 	"   bits 3:17 -- disk swap address/8
 	" second word: process pid
-	" third word:  used for smes/rmes
-	" fourth word: ??
+	" third word:  smes/rmes status:
+	"	0: not waiting
+	"	-1: this process waiting (rmes)
+	"	other: complement of sender pid
+	" fourth word: smes message
 ulist:
    0131000;1;0;0
    0031040;0;0;0