From 47ca72a1b7d8305137020e5125446ba545f738f0 Mon Sep 17 00:00:00 2001
From: Peter Ferrie <peter.ferrie@gmail.com>
Date: Mon, 18 Oct 2021 22:01:58 -0700
Subject: [PATCH] really support 24-bit seek

---
 src/constants.a       |  4 +--
 src/prodos.impl.lc2.a | 58 +++++++++++++++++++++++++++++--------------
 2 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/src/constants.a b/src/constants.a
index 3fe32c0ec..159f1ede2 100644
--- a/src/constants.a
+++ b/src/constants.a
@@ -149,8 +149,8 @@ CHEATS_ENABLED = %00001000
 iCurBlockLo    = $D401               ; constant
 iCurBlockHi    = $D403               ; constant
 launchpatch    = $D655               ; glue.launch.a
-iAddToPath     = $FE64               ; Roger Rabbit, avoid, use Infiltrator 2 style instead
-itraverse      = $D933               ; Roger Rabbit, avoid, use Infiltrator 2 style instead
+iAddToPath     = $FE6C               ; Roger Rabbit, avoid, use Infiltrator 2 style instead
+itraverse      = $D94A               ; Roger Rabbit, avoid, use Infiltrator 2 style instead
 ldrhi          = $56                 ; constant
 namlo          = $57                 ; constant
 namhi          = $58                 ; constant
diff --git a/src/prodos.impl.lc2.a b/src/prodos.impl.lc2.a
index ded4f1355..9e41971c2 100644
--- a/src/prodos.impl.lc2.a
+++ b/src/prodos.impl.lc2.a
@@ -222,43 +222,63 @@ resetval=$f0
          stx   blkofflo
          stx   blkoffhi
          stx   reqcmd
+@seekloop
          jsr   @reset
-         ldx   sizelo
+         ldy   sizelo
          bne   @seek64
          cmp   ldrhi
          bcc   @seek64
          bne   @seek32
-         ldx   ldrlo
-         beq   @seek32
-
-@seek64
-         sta   sizehi
-         sta   sizelo
-         jsr   @seekreset
-         lda   ldrhi
-         sbc   #resetval
-         sta   ldrhi
+         cmp   ldrlo
+         bcc   @seek64
 
 @seek32
          lda   ldrhi
+         ldx   ldrlo
+         +HIDE_NEXT_BYTE
+@seek64
+         tax
          sta   sizehi
-         lda   ldrlo
-         sta   sizelo
-         jsr   @seekreset
+         stx   sizelo
          lda   ldrhi
+         pha
+         lda   sizehi
+         pha
+         lda   ldrlo
+         pha
+         txa
+         pha
+         tya
+         pha
+         jsr   @seekreset
+         pla
+         tay
+         sec
+         pla
+         sta   ldrlo
+         pla
+         sbc   ldrlo
+         sta   ldrlo
+         pla
+         sta   ldrhi
+         pla
+         sbc   ldrhi
+         sta   ldrhi
+         tya
+         sbc   #0
+         sta   sizelo
          ora   ldrlo
-         bne   @jmp_zp
-         dec   blkidx
-         sta   treeidx
+         ora   ldrhi
+         bne   @seekloop
 @link_jmpzp
-         beq   @jmp_zp ;always
+         jmp   @jmp_zp
 
 @seekreset
          jsr   hddrdwrpart
 @reset
          lda   #resetval
          sta   blefthi
-         stx   bleftlo
+         sta   bleftlo
          rts
 
 @imp_read