From da96e23cc74b2160c0ec0288b3f99a286644d509 Mon Sep 17 00:00:00 2001
From: Mattias Hansson <mattias@techserio.com>
Date: Fri, 2 Jan 2026 16:16:05 +0100
Subject: [PATCH] Cleaned up ZP usage.

---
 carddeck.c65   | 10 +++++-----
 cardgame.c65   |  5 ++++-
 cardmoves.c65  | 38 +++++++++++++++++++-------------------
 cardrender.c65 | 22 +++++++++++-----------
 gameloop.c65   | 17 ++++++++---------
 utils.c65      | 14 +++++++++++---
 6 files changed, 58 insertions(+), 48 deletions(-)

diff --git a/carddeck.c65 b/carddeck.c65
index bb3794f..53d26ca 100644
--- a/carddeck.c65
+++ b/carddeck.c65
@@ -95,7 +95,7 @@ FEND
 // Tab0=1, Tab1=2, Tab2=3, Tab3=4, Tab4=5, Tab5=6, Tab6=7 cards
 // Top card of each tableau is face up
 FUNC deal_tableaus
-  WORD ptr @ $fc
+  WORD ptr
 
   POINTER ptr -> pile_tab0
   deal_to_tableau(ptr, 1)
@@ -121,7 +121,7 @@ FEND
 
 // Clear the seen array
 FUNC validate_clear_seen
-  WORD ptr @ $fa
+  WORD ptr @ $86
   POINTER ptr -> validate_seen
   BYTE i
   FOR i = 0 TO 51
@@ -131,8 +131,8 @@ FEND
 
 // Check cards in a pile, mark as seen
 // Returns 0 if OK, 1 if duplicate found
-FUNC validate_pile({WORD pile_ptr @ $fa} out:{BYTE result})
-  WORD seen_ptr @ $fc
+FUNC validate_pile({WORD pile_ptr @ $a2} out:{BYTE result})
+  WORD seen_ptr @ $b2
   POINTER seen_ptr -> validate_seen
 
   BYTE count
@@ -166,7 +166,7 @@ FEND
 // Validate entire deck across all piles
 // Returns: 0=OK, 1=duplicate, 2=missing
 FUNC validate_deck(out:{BYTE result})
-  WORD ptr @ $fa
+  WORD ptr @ $98
   WORD seen_ptr @ $fc
   BYTE pile_result
   BYTE i
diff --git a/cardgame.c65 b/cardgame.c65
index 8734b6d..fe9896a 100644
--- a/cardgame.c65
+++ b/cardgame.c65
@@ -36,11 +36,14 @@ FUNC main
     sei
   ENDASM
 
+  // Save zero page for potential kernal operations later
+  save_zeropage()
+
   // Initialize game state
 #IFNDEF TEST_GAMES
   // Normal game: random shuffle and deal
   // Seed RNG with multiple entropy sources for better randomness
-  WORD timer_seed @ $fa
+  WORD timer_seed
   BYTE raster @ $d012
   BYTE extra_entropy
   BYTE warmup
diff --git a/cardmoves.c65 b/cardmoves.c65
index 99cb002..091ca78 100644
--- a/cardmoves.c65
+++ b/cardmoves.c65
@@ -31,8 +31,8 @@ FUNC card_color({BYTE card_id} out:{BYTE color})
 FEND
 
 // Get top card from pile (returns card with facedown bit, or PILE_END if empty)
-// Uses $fa - for source pile operations
-FUNC pile_top_card({WORD pile_ptr @ $fa} out:{BYTE card})
+// Uses $ac - for source pile operations
+FUNC pile_top_card({WORD pile_ptr @ $ac} out:{BYTE card})
   BYTE count
   count = PEEK pile_ptr[0]
   IF count == 0
@@ -43,8 +43,8 @@ FUNC pile_top_card({WORD pile_ptr @ $fa} out:{BYTE card})
 FEND
 
 // Remove top card from pile (returns the card, updates count)
-// Uses $fa - for source pile operations
-FUNC pile_pop({WORD pile_ptr @ $fa} out:{BYTE card})
+// Uses $9a - for source pile operations
+FUNC pile_pop({WORD pile_ptr @ $9a} out:{BYTE card})
   BYTE count
   count = PEEK pile_ptr[0]
   card = PEEK pile_ptr[count]
@@ -63,8 +63,8 @@ FUNC pile_push({WORD pile_ptr @ $fc} {BYTE card})
 FEND
 
 // Flip top card face-up if it's face-down
-// Uses $fa - for source pile operations
-FUNC pile_flip_top({WORD pile_ptr @ $fa})
+// Uses $9e - for source pile operations
+FUNC pile_flip_top({WORD pile_ptr @ $9e})
   BYTE count
   BYTE card
   BYTE is_facedown
@@ -165,10 +165,10 @@ FEND
 
 // Stock to Waste: Draw cards from stock to waste
 // draw_count = 1 or 3 depending on game variant
-// Stock is source @ $fa, Waste is destination @ $fc
+// Stock is source @ $94, Waste is destination
 FUNC move_stock_to_waste({BYTE draw_count} out:{BYTE success})
-  WORD stock_ptr @ $fa
-  WORD waste_ptr @ $fc
+  WORD stock_ptr @ $94
+  WORD waste_ptr
   POINTER stock_ptr -> pile_stock
   POINTER waste_ptr -> pile_waste
   BYTE stock_count
@@ -196,10 +196,10 @@ FUNC move_stock_to_waste({BYTE draw_count} out:{BYTE success})
 FEND
 
 // Reset Stock: Flip waste back to stock (all face-down)
-// Waste is source @ $fa, Stock is destination @ $fc
+// Waste is source @ $9c, Stock is destination
 FUNC move_reset_stock(out:{BYTE success})
-  WORD waste_ptr @ $fa
-  WORD stock_ptr @ $fc
+  WORD waste_ptr @ $9c
+  WORD stock_ptr
   POINTER waste_ptr -> pile_waste
   POINTER stock_ptr -> pile_stock
   BYTE waste_count
@@ -223,8 +223,8 @@ FUNC move_reset_stock(out:{BYTE success})
 FEND
 
 // Waste to Tableau
-FUNC move_waste_to_tab({WORD tab_ptr @ $fc} out:{BYTE success})
-  WORD waste_ptr @ $fa
+FUNC move_waste_to_tab({WORD tab_ptr} out:{BYTE success})
+  WORD waste_ptr @ $8c
   POINTER waste_ptr -> pile_waste
   BYTE card
   BYTE valid
@@ -248,8 +248,8 @@ FUNC move_waste_to_tab({WORD tab_ptr @ $fc} out:{BYTE success})
 FEND
 
 // Waste to Foundation
-FUNC move_waste_to_found({WORD found_ptr @ $fc} out:{BYTE success})
-  WORD waste_ptr @ $fa
+FUNC move_waste_to_found({WORD found_ptr} out:{BYTE success})
+  WORD waste_ptr @ $aa
   POINTER waste_ptr -> pile_waste
   BYTE card
   BYTE valid
@@ -273,7 +273,7 @@ FUNC move_waste_to_found({WORD found_ptr @ $fc} out:{BYTE success})
 FEND
 
 // Tableau to Foundation (top card only)
-FUNC move_tab_to_found({WORD tab_ptr @ $fa} {WORD found_ptr @ $fc} out:{BYTE success})
+FUNC move_tab_to_found({WORD tab_ptr @ $8e} {WORD found_ptr} out:{BYTE success})
   BYTE card
   BYTE valid
   BYTE is_facedown
@@ -305,7 +305,7 @@ FUNC move_tab_to_found({WORD tab_ptr @ $fa} {WORD found_ptr @ $fc} out:{BYTE suc
 FEND
 
 // Tableau to Tableau: Move card_count cards from src to dst
-FUNC move_tab_to_tab({WORD src_ptr @ $fa} {WORD dst_ptr @ $fc} {BYTE card_count} out:{BYTE success})
+FUNC move_tab_to_tab({WORD src_ptr @ $b0} {WORD dst_ptr} {BYTE card_count} out:{BYTE success})
   BYTE src_count
   BYTE start_idx
   BYTE bottom_card
@@ -358,7 +358,7 @@ FUNC move_tab_to_tab({WORD src_ptr @ $fa} {WORD dst_ptr @ $fc} {BYTE card_count}
 FEND
 
 // Foundation to Tableau (optional rule - some variants allow this)
-FUNC move_found_to_tab({WORD found_ptr @ $fa} {WORD tab_ptr @ $fc} out:{BYTE success})
+FUNC move_found_to_tab({WORD found_ptr @ $84} {WORD tab_ptr} out:{BYTE success})
   BYTE card
   BYTE valid
 
diff --git a/cardrender.c65 b/cardrender.c65
index be9928f..1dcd535 100644
--- a/cardrender.c65
+++ b/cardrender.c65
@@ -67,7 +67,7 @@ FUNC render_card({WORD screen_address} {WORD offset} {BYTE card_id})
   card_id_to_suit_rank(card_id, card_suit, card_rank)
 
   // Get rank charcode
-  WORD card_charcode_map_ptr @ $fa
+  WORD card_charcode_map_ptr @ $a0
   POINTER card_charcode_map_ptr -> card_charcode_map
 
   BYTE card_rank_charcode
@@ -79,14 +79,14 @@ FUNC render_card({WORD screen_address} {WORD offset} {BYTE card_id})
   ENDIF
 
   // Get suit charcode
-  WORD card_suit_charcode_map_ptr @ $fa
+  WORD card_suit_charcode_map_ptr @ $a0
   POINTER card_suit_charcode_map_ptr -> card_suit_charcode_map
 
   BYTE suit_charcode
   suit_charcode = PEEK card_suit_charcode_map_ptr[card_suit]
 
 
-  WORD p2 @ $fa
+  WORD p2 @ $a0
   SWITCH card_suit
     CASE CARD_SUIT_HEARTS
       POINTER p2 -> suit_graphic_hearts
@@ -291,7 +291,7 @@ FUNC render_card_body_partial({WORD screen_address} {WORD offset} {BYTE card_id}
   card_id_to_suit_rank(card_id, card_suit, card_rank)
 
   // Get rank charcode
-  WORD card_charcode_map_ptr @ $fa
+  WORD card_charcode_map_ptr @ $96
   POINTER card_charcode_map_ptr -> card_charcode_map
 
   BYTE card_rank_charcode
@@ -303,7 +303,7 @@ FUNC render_card_body_partial({WORD screen_address} {WORD offset} {BYTE card_id}
   ENDIF
 
   // Get suit charcode
-  WORD card_suit_charcode_map_ptr @ $fa
+  WORD card_suit_charcode_map_ptr @ $96
   POINTER card_suit_charcode_map_ptr -> card_suit_charcode_map
 
   BYTE suit_charcode
@@ -329,7 +329,7 @@ FUNC render_card_body_full({WORD screen_address} {WORD offset} {BYTE card_id})
   card_id_to_suit_rank(card_id, card_suit, card_rank)
 
   // Get rank charcode
-  WORD card_charcode_map_ptr @ $fa
+  WORD card_charcode_map_ptr @ $90
   POINTER card_charcode_map_ptr -> card_charcode_map
 
   BYTE card_rank_charcode
@@ -341,14 +341,14 @@ FUNC render_card_body_full({WORD screen_address} {WORD offset} {BYTE card_id})
   ENDIF
 
   // Get suit charcode
-  WORD card_suit_charcode_map_ptr @ $fa
+  WORD card_suit_charcode_map_ptr @ $90
   POINTER card_suit_charcode_map_ptr -> card_suit_charcode_map
 
   BYTE suit_charcode
   suit_charcode = PEEK card_suit_charcode_map_ptr[card_suit]
 
   // Get suit graphic pointer
-  WORD p2 @ $fa
+  WORD p2 @ $90
   SWITCH card_suit
     CASE CARD_SUIT_HEARTS
       POINTER p2 -> suit_graphic_hearts
@@ -810,7 +810,7 @@ FUNC render_card_left_edge({WORD screen_address} {WORD offset} {BYTE card_id})
   card_id_to_suit_rank(card_id, card_suit, card_rank)
 
   // Get rank charcode
-  WORD card_charcode_map_ptr @ $fa
+  WORD card_charcode_map_ptr @ $a6
   POINTER card_charcode_map_ptr -> card_charcode_map
 
   BYTE card_rank_charcode
@@ -822,14 +822,14 @@ FUNC render_card_left_edge({WORD screen_address} {WORD offset} {BYTE card_id})
   ENDIF
 
   // Get suit charcode
-  WORD card_suit_charcode_map_ptr @ $fa
+  WORD card_suit_charcode_map_ptr @ $a6
   POINTER card_suit_charcode_map_ptr -> card_suit_charcode_map
 
   BYTE suit_charcode
   suit_charcode = PEEK card_suit_charcode_map_ptr[card_suit]
 
   // Get suit graphic pointer
-  WORD p2 @ $fa
+  WORD p2 @ $a6
   SWITCH card_suit
     CASE CARD_SUIT_HEARTS
       POINTER p2 -> suit_graphic_hearts
diff --git a/gameloop.c65 b/gameloop.c65
index b8c21ae..cc0baf5 100644
--- a/gameloop.c65
+++ b/gameloop.c65
@@ -236,7 +236,7 @@ FEND
 // Convert pile ID to pile data pointer
 // ============================================================================
 FUNC pile_id_to_pointer({BYTE pile_id} out:{WORD pile_ptr})
-  WORD ptr @ $fa
+  WORD ptr
 
   SWITCH pile_id
     CASE PILE_ID_STOCK
@@ -386,7 +386,7 @@ FEND
 // Returns card_id (0-51) and valid flag (1=valid, 0=no selection)
 // ============================================================================
 FUNC get_selected_card_info(out:{BYTE card_id} out:{BYTE valid})
-  WORD pile_ptr @ $fa
+  WORD pile_ptr @ $80
   BYTE pile_count
   BYTE card_index
   BYTE card
@@ -534,7 +534,7 @@ FEND
 // Clears the area first to remove artifacts from previous render
 // ============================================================================
 FUNC render_pile_by_id({BYTE pile_id})
-  WORD pile_ptr @ $fa
+  WORD pile_ptr @ $92
   WORD screen_offset
 
   pile_id_to_pointer(pile_id, pile_ptr)
@@ -599,7 +599,7 @@ FEND
 // Returns 1 if won, 0 otherwise
 // ============================================================================
 FUNC check_win_condition(out:{BYTE is_won})
-  WORD ptr @ $fa
+  WORD ptr @ $a4
   BYTE count
 
   is_won = 1  // Assume won, set to 0 if any foundation incomplete
@@ -650,7 +650,8 @@ FUNC handle_click_on_pile({BYTE clicked_pile} {BYTE click_row})
   BYTE success
   WORD src_ptr
   WORD dst_ptr
-  WORD tab_ptr @ $f8
+  //WORD tab_ptr @ $f8
+  WORD tab_ptr
   BYTE tab_col
   BYTE tab_index
   BYTE j
@@ -684,8 +685,6 @@ FUNC handle_click_on_pile({BYTE clicked_pile} {BYTE click_row})
 
     IF clicked_pile == PILE_ID_STOCK
       // Stock: draw cards
-      WORD stock_ptr @ $fa
-      POINTER stock_ptr -> pile_stock
       move_stock_to_waste(game_draw_mode, success)
       IF success
         render_pile_by_id(PILE_ID_STOCK)
@@ -820,9 +819,9 @@ FUNC game_loop
   BYTE button_state
   BYTE clicked
   BYTE is_won
-  WORD src_ptr @ $fa
+  WORD src_ptr @ $8a
   WORD src_end_ptr
-  WORD dst_ptr @ $fc
+  WORD dst_ptr
 
   // Copy sprite data to $2200 (sprite block 136)
   // $2000-$21FF reserved for charset
diff --git a/utils.c65 b/utils.c65
index 182a4d1..9935784 100644
--- a/utils.c65
+++ b/utils.c65
@@ -4,14 +4,14 @@
 
 GOTO __skip_lib_utils
 
-FUNC fill_mem({WORD start_addr @ $fa} {WORD end_addr} {BYTE value})
+FUNC fill_mem({WORD start_addr @ $fb} {WORD end_addr} {BYTE value})
 
   FOR start_addr = start_addr TO end_addr
     POKE start_addr , value
   NEXT
 FEND
 
-FUNC mem_copy({WORD start_addr @ $fa} {WORD end_addr} {WORD target_addr @ $fc})
+FUNC mem_copy({WORD start_addr @ $fb} {WORD end_addr} {WORD target_addr @ $fd})
   BYTE value
 
   FOR start_addr = start_addr TO end_addr
@@ -22,7 +22,7 @@ FUNC mem_copy({WORD start_addr @ $fa} {WORD end_addr} {WORD target_addr @ $fc})
 FEND
 
 
-FUNC mem_copy_range({WORD start_addr @ $fa} {WORD target_addr @ $fc} {WORD range})
+FUNC mem_copy_range({WORD start_addr @ $fb} {WORD target_addr @ $fd} {WORD range})
   BYTE value
 
   WHILE range
@@ -137,6 +137,14 @@ FUNC wait_key
   WEND
 FEND
 
+FUNC save_zeropage
+  mem_copy_range($0000, $cf00, 256)
+FEND
+
+FUNC restore_zeropage
+  mem_copy_range($cf00, $0000, 256)
+FEND
+
 LABEL __skip_lib_utils
 
 #IFEND