From 1dcddb2569fa3b9b422737ed912723752316c5e2 Mon Sep 17 00:00:00 2001
From: Michaelangel007 <michaelangel007@sharedcraft.com>
Date: Mon, 17 Jul 2017 15:32:06 -0700
Subject: [PATCH] Inlined GetDestAddr, 692 bytes

---
 README.md   |   2 +-
 linuxlogo.s | 126 +++++++++++++++++++++++++---------------------------
 ll_6502.dsk | Bin 143360 -> 143360 bytes
 3 files changed, 61 insertions(+), 67 deletions(-)

diff --git a/README.md b/README.md
index b6e7077..1abd6dd 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 
 Linux Logo in 6502 assembly language.
 
-Size: 696 ($2B8) bytes
+Size: 692 ($2B4) bytes
 
 
 # Screenshots
diff --git a/linuxlogo.s b/linuxlogo.s
index 055c169..a27a822 100644
--- a/linuxlogo.s
+++ b/linuxlogo.s
@@ -246,14 +246,15 @@ Unpack2Bits
 
 ; DoublePixel
         stx zSaveX
+        sty zSaveY
+        
         lda zUnpackBits
-        and #3      ; A=000000ba
-        pha
-        asl         ; A=00000ba0
-        asl         ; A=0000ba00
-        sta zMask   
-        pla
-        ora zMask   ; A=0000baba 
+        asl                 ; A=?????ba0
+        asl                 ; A=????ba00
+        eor zUnpackBits     ; A=????xxyy
+        and #%00001100      ; A=????xx00
+        eor zUnpackBits     ; A=????baba
+        and #%00001111      ; A=0000baba
 
         ldx #0
         stx zMask
@@ -267,14 +268,16 @@ MakeShiftMask
         bne MakeShiftMask
 NoShiftSherlock
 
-        cmp #$80            ; msb of byte0 set?
+        asl                 ; msb of byte0 set?
         rol zMask           ; shift in to lsb of byte1
 
-        ldx zDstShift       ; x={0,1,2} + 4 < 7
-        cpx #3              ; all bits fit into dest byte?
+        sec                 ; MSB=1 color=blue/orange
+        ror
+
+        ldy zDstShift       ; x={0,1,2} + 4 < 7
+        cpy #3              ; all bits fit into dest byte?
 
         ldx zSaveX
-        ora #$80
         ora UnpackAddr,X    ; do all bits that fit
         sta UnpackAddr,X
         bcc UpdateDestOffset
@@ -291,71 +294,20 @@ NoShiftSherlock
 
         ; x = x + 4 - 7
         ; x = x - 3
-        ldx zDstShift
-        dex
-        dex
-        dex
-
+        ldy zDstShift
+        dey
+        dey
+        dey
         bcc LineNotDone     ; C = x < 28
 
 ; ------------------------------------------------------------------------
 ; Copy Buffer to HGR
 
-        sty zSaveY
         inc zCursorY
-        jsr GetDestAddr
-
-        ldx #7              ; Repeat each scanline 8 times
-Draw8Rows
-        ldy #0
-CopyScanLine
-        lda UnpackAddr,Y      
-        sta (zHgrPtr),Y
-
-        cpx #0              ; Clear source on last scanline copy
-        bne CopyNextByte
-        txa
-        sta UnpackAddr,Y
-CopyNextByte
-        iny
-        cpy #40             ; 280/7 = 40 bytes/scanline
-        bne CopyScanLine
-
-        clc                 ; y = y+1
-        lda zHgrPtr+1       ; addr_y+1 = addr_y + $0400
-        adc #$04
-        sta zHgrPtr+1
-        dex
-        bpl Draw8Rows
-
-        ldy zSaveY
-               
-        lda zCursorY
-        cmp #$14            ; Y=$40 .. $A0, Rows $8..$13 (inclusive)
-        bcs OuputDone
-
-        ldx #0
-        stx zSaveX
-        beq LineNotDone     ; Next Scan Line, start at dst bit 0
-
-UpdateDestOffset
-        ldx zDstShift
-        inx
-        inx
-        inx
-        inx
-LineNotDone
-        stx zDstShift
-        clc
-        ldx zSaveX
-OuputDone
-        rts
 
 ; ------------------------------------------------------------------------
 ; Udpate the Text Address
 ; Update the HGR scanline Address
-; Clear the Text buffer
-GetDestAddr
         lda zCursorY
         jsr BASCALC
 
@@ -366,9 +318,51 @@ GetDestAddr
         clc             ; every 8 HGR scanline address
         adc #$1c        ; is Text Page $04 + $1C = HGR Page $20
         sta zHgrPtr+1
+; ------------------------------------------------------------------------
 
+        ldx #7              ; Repeat each scanline 8 times
+Draw8Rows
+        ldy #39             ; 280/7 = 40 bytes/scanline
+CopyScanLine
+        lda UnpackAddr,Y      
+        sta (zHgrPtr),Y
+
+        txa                 ; Clear source on last scanline copy
+        bne CopyNextByte
+        sta UnpackAddr,Y
+CopyNextByte
+        dey
+        bpl CopyScanLine
+
+        clc                 ; y = y+1
+        lda zHgrPtr+1       ; HGR addr_y+1 = addr_y + $0400
+        adc #$04
+        sta zHgrPtr+1
+
+        stx zSaveX          ; X=0 last loop iteration
+        dex
+        bpl Draw8Rows
+
+        iny                 ; Y=0 -> zDstShift
+               
+        lda zCursorY
+        cmp #$14            ; Y=$40 .. $A0, Rows $8..$13 (inclusive)
+        bcs OuputDone
+        bcc LineNotDone     ; Next Scan Line, start at dst bit 0
+
+UpdateDestOffset            ; C=0 from NoShiftSherlock 
+        iny
+        iny
+        iny
+        iny
+LineNotDone
+        sty zDstShift
+        ldx zSaveX          ; NOTE: C=0 from CMPs above
+        ldy zSaveY
+OuputDone
         rts
 
+
 ; ------------------------------------------------------------------------
 
 CpuType = * + 13 + 40
diff --git a/ll_6502.dsk b/ll_6502.dsk
index cab2087614c1e2e5757ae8159cc52fdeb21d7c43..fef23a40b53d3aba88f8d781f5be0d6a702a7929 100644
GIT binary patch
delta 191
zcmV;w06_nM;0S==2!ON!1!|WPTmkNr5DE>JYXK7}Pw0mE;3%d034k5YKb_D&r2UA9
zh>$(zC8Z@G!TY5sg(jsb7-<}ZCzmg40Wz0zYXOc2|NsC00133018e~$7SIZe(F%>y
z3aOxtp9-S3ptX*m3XGwbK3)MP8L$eDu?mc`3eX&_!29q9$>7l7@C>Qrji8r(UI88k
t;tGZSx#O3iUI8c=Y6_7k=*Yk*(Dmjer6tK1(CEe`sjHpRx8ZC7AH%b+StS4f

delta 179
zcmV;k08IaY;0S==2!ON!1!|W8Y61I}YXK7+Lg<G1;3%d034k5YKb_D&r2UA9h>$Sm
zB_Lf2mpp3$GM8#y0hSE^55WKb|NsC0013F418e~$7Ssxi)e4Q)3aOxtqY9$7ptX*q
z3XG+fK3)MP8MF$HwF->33eX&_!29q9$>7l7@C>Qrjii@-UI88k<_d-Wx#yRmUI8c=
hZVHho=*Yk*(Dmjer6tK1(CEe`sjHpVx8ZC7AHzScR;&O3