From 633b13175b661950def5eef0acff23a61dcc44ef Mon Sep 17 00:00:00 2001
From: Bobbi Webber-Manners <bobbi.manners@gmail.com>
Date: Mon, 26 Dec 2022 21:22:32 -0500
Subject: [PATCH] Unrolled loop for faster SHR mode plotting. Thx John Brooks
 :)

---
 applecorn.po | Bin 819200 -> 819200 bytes
 auxmem.shr.s |  43 ++++++++++++++++++++++++-------------------
 2 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/applecorn.po b/applecorn.po
index cea55c0677e0650cd4115b6dd4ba449e61da3530..14e6ef0cbfea9bdc94b2123141daaaea39a0ab5a 100644
GIT binary patch
delta 74
zcmZo@FluNp+K|J-Eh5U$@R&himad3sb2&?UISV5YGXXI(5QF%vK+Fcj>_E%`#GF9P
N1;pIj%UO6js{tLQ6vO}k

delta 74
zcmZo@FluNp+K|J-tuDgQ@R&himae);b2&?UISV5YGXXI(5QF%vK+Fcj>_E%`#GF9P
N1;pIj%UO6js{tkj6zBi|

diff --git a/auxmem.shr.s b/auxmem.shr.s
index 58f65b8..3ddd470 100644
--- a/auxmem.shr.s
+++ b/auxmem.shr.s
@@ -265,25 +265,30 @@ SHRPRCHAR     SEC
               LDA   #$E1
               STA   VDUBANK2
               JSR   SHRCHARADDR            ; Screen addr in VDUADDR
-              LDX   #$00                   ; First row of char
-:L1           LDY   #$00
-              LDA   [VDUADDR2]             ; Load exploded font data 1st byte
-              JSR   SHRCOLBYTE
-              STA   [VDUADDR]              ; Store on screen
-              INY
-              INC   VDUADDR2+0             ; Increment exploded font ptr
-              BNE   :S1
-              INC   VDUADDR2+1
-:S1           LDA   [VDUADDR2]             ; Load exploded font data 2nd byte
-              JSR   SHRCOLBYTE
-              STA   [VDUADDR],Y            ; Store on screen
-              INC   VDUADDR2+0             ; Increment exploded font ptr
-              BNE   :S2
-              INC   VDUADDR2+1
-:S2           JSR   SHRNEXTROW             ; Add 160 to VDUADDR
-              INX                          ; Next row of font
-              CPX   #$08                   ; Last row?
-              BNE   :L1
+
+* 65816 code contributed by John Brooks follows ...
+
+              PHB                          ; Save data bank
+              LDA   VDUADDR2+2             ; Push font Bank onto stack
+              PHA
+              PLB                          ; Set data bank to font bank
+              CLC
+              XCE
+              REP   #$30
+              LDY   VDUADDR2               ; Font src ptr
+              LDX   VDUADDR                ; SHR dst ptr
+SrcFont       =     $000000
+DstShr        =     $E10000
+              LUP   8
+              LDA   !SrcFont,Y
+              STAL  DstShr,X   
+SrcFont       =     SrcFont+2
+DstShr        =     DstShr+160
+              --^           
+              PLB
+              SEC
+              XCE
+              MX    %11
               RTS