# HG changeset patch
# User Robert McIntyre <rlm@mit.edu>
# Date 1333876249 18000
# Node ID dea7e476eba746e54fd8a7b3ba9cf3384b222b26
# Parent  93e74ed34305da8db1149c6270c2d2e07bf95580
preliminary item-writer complete

diff -r 93e74ed34305 -r dea7e476eba7 clojure/com/aurellem/run/bootstrap_0.clj
--- a/clojure/com/aurellem/run/bootstrap_0.clj	Sun Apr 08 03:00:51 2012 -0500
+++ b/clojure/com/aurellem/run/bootstrap_0.clj	Sun Apr 08 04:10:49 2012 -0500
@@ -760,11 +760,7 @@
         [return-high return-low] (disect-bytes-2 return-address)]
     (flatten
      [0xF3 ;; disable interrupts
-      ;;0xC5 ;; push junk onto stack
-      ;;0xD5
-      ;;0xE5
-      ;;0xF5
-      
+
       0x1E  ;; load limit into E
       limit
 
@@ -776,7 +772,6 @@
       0x0E   ;; C == 1 means input-first nybble
       0x01   ;; C == 0 means input-second nybble
       
-
       ;; Input Section
 
       0x3E ;; load 0x20 into A, to measure dpad
@@ -831,12 +826,6 @@
       0x20 ;; jump back to input section if not done
       0xE4 ;; literal -28
 
-      ;; cleanup
-      ;;0xF1
-      ;;0xE1
-      ;;0xD1
-      ;;0xC1
-      
       0xFB ;; re-enable interrupts
       
       0xC3
@@ -936,9 +925,12 @@
       0x3F  ;; (item-hack) set carry flag no-op
 
       ;; load 1 into C.
-      0x0E   ;; C == 1 means input-first nybble
-      0x01   ;; C == 0 means input-second nybble
-            
+      0x0E   ;; C == 0 means input-first nybble
+      0x01   ;; C == 0xFF means input-second nybble
+
+      0x0D   ;; (item-hack) (dec C)
+      0x2B   ;; (item-hack) (dec HL) no-op
+      
       0x21 ;; load target into HL
       target-low
       target-high
@@ -976,45 +968,58 @@
       0x47 ;; load A into B
       
       0x0D ;; dec C
+      0x37 ;; (item-hack) set-carry flag
       ;; branch based on C:
       0x20 ;; JR NZ
-      0x07 ;; skip "input first nybble" below
-
+      0x08 ;; skip "input first nybble" below
       
-      ;; input first nybble
-     
-      0xCB
-      0x37  ;; swap nybbles on A
-
-      0x57  ;; A -> D
-
-      0x18
-      0xEC  ;; literal -20 -- go back to input section
-
       ;; input second nybble
 
       0x0C ;; inc C
-      
+      0x37 ;; (item-hack) set-carry flag no-op
+
+      0x00 ;; (item-hack) no-op
       0xE6 ;; select bottom bits
       0x0F
+      0x37 ;; (item-hack) set-carry flag no-op
 
+      0x00 ;; (item-hack) no-op
       0xB2 ;; (OR A D) -> A
 
       0x22 ;; (do (A -> (HL)) (INC HL))
 
       0x1D ;; (DEC E)
 
+      0x00 ;; (item-hack) 
       0x20 ;; jump back to input section if not done
-      0xE4 ;; literal -28
+      0xDA ;; literal -36 == TM 18 (counter)
+      0x01 ;; (item-hack) will never reach this instruction
 
+      ;; input first nybble
+      0x00
+      0xCB
+      0x37  ;; swap nybbles on A
+
+      0x57  ;; A -> D
+
+      0x37
+      0x18
+      0xD5  ;; literal -20 == TM13; go back to input section
+      0x01
+
+      0x3A  ;; (item-hack) these two bytes can be anything.
+      0x01 
       ;; cleanup
       ;;0xF1
       ;;0xE1
       ;;0xD1
       ;;0xC1
-      
-      0xFB ;; re-enable interrupts
-      
-      0xC3
+      0x00   ;; (item-hack) no-op
+      0xBF   ;; (CP A A) ensures Z
+      ;;0xFB ;; re-enable interrupts;; unnecessary
+      0xCA   ;; (item-hack) jump if Z
       return-low
-      return-high ])))
+      return-high
+
+      0x01   ;; (item-hack) will never be reached.
+      ])))