From d90c75703d7a9ca53fded2a40fa35344279ed843 Mon Sep 17 00:00:00 2001
From: "B. Watson" <yalhcru@gmail.com>
Date: Wed, 6 Jan 2016 04:04:57 -0500
Subject: document the compression before I forget

---
 comptitle.s.in | 43 ++++++++++++++++++++++++++-----------------
 1 file changed, 26 insertions(+), 17 deletions(-)

(limited to 'comptitle.s.in')

diff --git a/comptitle.s.in b/comptitle.s.in
index 7862b3d..b8ed688 100644
--- a/comptitle.s.in
+++ b/comptitle.s.in
@@ -1,3 +1,4 @@
+;;; see titlecompression.txt to understand how this works!
 
 ; cl65 -o comptitle.xex -t none comptitle.s
 
@@ -37,6 +38,13 @@ table:
 
  ; decompression code starts here
 init:
+ lda #0
+
+ ;;; for benchmarking only, remove!
+ ;sta RTCLOK
+ ;sta RTCLOK+1
+ ;sta RTCLOK+2
+
  lda #>imgsize
  sta pagecount
  lda #>compdata
@@ -62,7 +70,22 @@ copyloop:
  beq notcode
 
  ; got a zero-run code. A = number of bytes of zeroes to store.
- jmp storezerorun
+storezerorun:
+ sty tmp
+ tay
+ dey
+ lda #0
+szloop:
+ sta (dstptr),y
+ jsr incdest
+ beq done
+nohi2:
+ dey
+ bpl szloop
+
+ ldy tmp
+ clc
+ bcc storedone
 
 notcode:
  lda tmp
@@ -83,24 +106,10 @@ storedone:
  bne copyloop ; always branch (since srcptr never wraps around to 0)
 
 done:
+ ;;; for benchmarking only, remove!
+ ;.byte $02 ; CIM, drops us to atari800 monitor
  rts
 
-storezerorun:
- sty tmp
- tay
- dey
- lda #0
-szloop:
- sta (dstptr),y
- jsr incdest
- beq done
-nohi2:
- dey
- bpl szloop
-
- ldy tmp
- jmp storedone
-
 incdest:
  inc dstptr
  bne iddone
-- 
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