From 81908682ab60f1be4b692418e29dfcc6806c2feb Mon Sep 17 00:00:00 2001
From: Michaelangel007 <michaelangel007@sharedcraft.com>
Date: Thu, 27 Jul 2017 09:23:32 -0700
Subject: [PATCH] Shave off another byte by copying HGR scanliens vertically --
 Thank Mike B

---
 README.md   |   2 +-
 linuxlogo   | Bin 660 -> 659 bytes
 linuxlogo.s |  65 ++++++++++++++++++++++++++--------------------------
 ll_6502.dsk | Bin 143360 -> 143360 bytes
 4 files changed, 33 insertions(+), 34 deletions(-)

diff --git a/README.md b/README.md
index 1aa7fb7..ec0d6e6 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 
 Optimized Linux Logo in 6502 assembly language for size.
 
-Size: 660 ($294) bytes
+Size: 659 ($293) bytes
 
 
 # Screenshots
diff --git a/linuxlogo b/linuxlogo
index aa427cff23c325b11b3735dc40b14a36cb2886e8..eb842268a26b359eacc525af255e40798ab98569 100644
GIT binary patch
delta 171
zcmV;c095~!1(OAkAr`L+jIaugu?nf6jeZKEwxG3+e+rC%kvAqfj|z^E3XG8o&>XG6
z`|t+I;Lzak45{Ode+sR?`^g2+1)>2U(Fu)#z^Mm?C7=L={e=0g!3u@`xx$f`CILy2
zz7_$ok<~0cLg@#n=!W^F`yJ3fozOp+;3$wU<|U;iAi?{fC#5M#B&xa4KZYrhDCp?u
Z=-@z*@rvmns;K~(&_9Lwh_gQdRRO9aRO0{u

delta 172
zcmV;d08{^y1(XGlAr`O-jIj!hvI?o7jeiQFwxG3+fC`L(kvAqfkP42G3XGBp&>XG6
z`|t+I;Lzak45{OdfC{a@`^g2+1)>2U(Fu)#z^Mm?C7=L={e=0g!U~1{xx<l{CIL#3
zz7_$pk<~0dL+J;o=!W^F`yJ3fozOp+;3$wV<|U;iAi?{kDM=)SDWV6UC%Mo+ktmAL
a1DVi2h!FA^r739yg(-&lipsM-0aXF6t5JUd

diff --git a/linuxlogo.s b/linuxlogo.s
index a731264..76d9511 100644
--- a/linuxlogo.s
+++ b/linuxlogo.s
@@ -308,47 +308,46 @@ MakeShiftMask
         lda zCursorY
         jsr BASCALC
 
+; ------------------------------------------------------------------------
+; Copy unpacked buffer to 8 HGR scanlines
+
+Draw8Rows
+        ldy #39             ; 280/7 = 40 bytes/scanline
+
 ; Yes, this is evil ...
 ; Instead of copying zTxtPtr over to zHgrPtr
 ; We re-use it by forcing it to be a HGR address!
 ; This *is* safe BECAUSE we call JSR BASCALC _before_ we do any text printing.
-        lda zTxtPtr+1   ; every 8 HGR scanline address
-        eor #$24        ; is Text Page $04 + $1C = HGR Page $20; CLC, ADC #$1C
-        sta zTxtPtr+1   ; but we can optimize for HGR page 1 via EOR #$24 -- Thanks Mike B.!
+        lda zTxtPtr+1       ; Translate text page row address to 
+        eor #$24            ;   every eighth HGR row address 
+        tax 
 
-; ------------------------------------------------------------------------
-; Copy unpacked buffer to 8 HGR scanlines
-
-        ldx #7              ; Repeat each scanline 8 times
-Draw8Rows
-        ldy #39             ; 280/7 = 40 bytes/scanline
-CopyScanLine
-        lda UnpackAddr,Y      
+Copy7x8
+        lda UnpackAddr,Y
+        stx zTxtPtr+1       
         sta (zTxtPtr),Y
+        inx                 ; y = y+1
+        inx                 ; HGR addr_y+1 = addr_y + $0400
+        inx      
+        inx
+        cpx #$40            ; hit HGR page 2 ? i.e. 8 scan lines done?
+        bcc Copy7x8         ; Loop until 7x8 pixel block is complete 
 
-        txa                 ; Clear source on last scanline copy
-        bne CopyNextByte
-        sta UnpackAddr,Y
-CopyNextByte
-        dey
-        bpl CopyScanLine
+        txa 
+        sbc #$20            ; Reset pointer for top of next 7x8 block 
+        tax 
+        lda #0 
+        sta UnpackAddr,Y    ; Clear source on last scanline copy 
+        sta zDstOffset      ; reset to start of unpack buffer
+        dey 
+        bpl Copy7x8         ; Loop until all 280x8 pixels are copied 
 
-        clc                 ; y = y+1
-        lda zTxtPtr+1       ; HGR addr_y+1 = addr_y + $0400
-        adc #$04
-        sta zTxtPtr+1
-
-        stx zDstOffset      ; X=0 last loop iteration
-        txa                 ; A=0 zDstShift
-        dex
-        bpl Draw8Rows
-
-        ldx zCursorY        ; (1) X=14, see (2)
-        cpx #$14            ; Y=$40 .. $A0, Rows $8..$13 (inclusive)
-FitSameByte
-        sta zDstShift
-        ldy zSrcOffset      ; NOTE: C=0 from CMPs above
-        rts
+        ldx zCursorY        ; (1) X=14, see (2) 
+        cpx #$14            ; Y=$40 .. $A0, Rows $8..$13 (inclusive) 
+FitSameByte 
+        sta zDstShift 
+        ldy zSrcOffset      ; NOTE: C=0 from CMPs above 
+        rts 
 
 
 ; ========================================================================
diff --git a/ll_6502.dsk b/ll_6502.dsk
index 2a5f52e200a70471aae21592d28025affd16bd12..7b9ec17a5eeed802baa768ed302efd7c727a3d87 100644
GIT binary patch
delta 200
zcmV;(05|`D;0S==2!ON!2WpoHY619{|7rmSJwoXRsOX0IrTZPwKb_D&nBXXoFXkns
zB_P53peLm%NhGSd&_9MLktpcs=;+`;knxJ?AgZYVnb1Fl`G}W8YXQ9k{{RV-mji48
zA{MU-jIaugu?nf6jeZKEwxG3+e+rC%mp)zrCK-<kj*tqBkqXcpt-$;62Fc*i;P4Eo
z<BflpdTaq32Ehu2{<*@Jn`{9l7)c6|DCo$*DA4uhC8Z_F7trX&C8?{OvA5Z50Vl(7
CD`2hw

delta 199
zcmV;&0671E;0S==2!ON!2WpoFY61C{YXJp5L+J;o=!W^F`yJ3fozOp+;3$wV<|U;i
zAi?{kDM=)SDWV6UC%Mo+ktmAL1DVi2h!FA^r739yg(-&liprNlYXQ9j011?r18e~z
z7O)D8u?mf{3aOxte+r_uptX*G3XFl5K3)MP8ITH&kqV5G3eX&_!29q9$>7l7@C>Qr
zjewVWYylev!U~1{xx<&6Yyl=1N(zxE=*Yk*(Dmjer6tK1(CEe`sjHo`x7lm~C&O>Y
BTS@=`