From 1c1ed5d95bed95ea643ad92015ba4782013622e9 Mon Sep 17 00:00:00 2001
From: 4am <a2_4am@sent.com>
Date: Thu, 9 Aug 2018 19:31:26 -0400
Subject: [PATCH] patch universal RWTS later to disable drive recalibration, to
 reduce false negatives failing to read the boot sector

---
 src/mods/universalrwts.a | 3 +--
 src/passport.a           | 5 +++++
 src/rwts.a               | 9 +++++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/mods/universalrwts.a b/src/mods/universalrwts.a
index 10a4869..7879b38 100644
--- a/src/mods/universalrwts.a
+++ b/src/mods/universalrwts.a
@@ -121,8 +121,7 @@ universalrwts
          !byte $88,$D0,$FD,$E6,$46,$D0,$F7,$E6,$47,$D0,$F3,$A0,$0C,$B1,$48,$F0
          !byte $5A,$C9,$04,$F0,$58,$6A,$08,$B0,$03,$20,$00,$B8,$A0,$30,$8C,$78
          !byte $05,$AE,$F8,$05,$20,$44,$B9,$90,$24,$CE,$78,$05,$10,$F3,$AD,$78
-; $BDD2 is patched to disable track recalibration after failing to find an address prologue 48 times
-         !byte $04,$48,$B0,$30,$20,$95,$BE,$CE,$F8,$06,$F0,$28,$A9,$04,$8D,$F8
+         !byte $04,$48,$A9,$60,$20,$95,$BE,$CE,$F8,$06,$F0,$28,$A9,$04,$8D,$F8
          !byte $04,$A9,$00,$20,$5A,$BE,$68,$20,$5A,$BE,$4C,$BC,$BD,$A4,$2E,$CC
          !byte $78,$04,$F0,$1C,$AD,$78,$04,$48,$98,$20,$95,$BE,$68,$CE,$F8,$04
          !byte $D0,$E5,$F0,$CA,$68,$A9,$40,$28,$4C,$48,$BE,$F0,$39,$4C,$AF,$BE
diff --git a/src/passport.a b/src/passport.a
index d9233c6..87f9cf1 100755
--- a/src/passport.a
+++ b/src/passport.a
@@ -344,6 +344,11 @@ UseUniversal
 ;
 +        jsr   PatchUniversalRWTSForAdaptive
 ;
+; Disable drive recalibration on bad sectors so we give up on bad sectors
+; faster and detect unformatted or specially structured tracks faster.
+;
+         jsr   PatchUniversalRWTSForNoRecal
+;
 ; Some disks have different epilogues on track 0, so we stop using the
 ; adaptive RWTS so we don't falsely accuse those disks of being damaged.
 ;
diff --git a/src/rwts.a b/src/rwts.a
index c7b9fd2..68cc91d 100755
--- a/src/rwts.a
+++ b/src/rwts.a
@@ -123,6 +123,15 @@ IgnoreAddressChecksum
          rts
 }
 
+!zone {
+PatchUniversalRWTSForNoRecal
+         lda   #$B0
+.x8      sta   $BDD2
+         lda   #$30
+.x9      sta   $BDD3
+         rts
+}
+
 !zone {
 PatchUniversalRWTSForAdaptive
 ; out:    N flag set