shrink saved stack

src/4cade.a

@@ -78,8 +78,9 @@ RestoreStackNextTime
                                      ; reset to branch so we don't try to
          sta   RestoreStackNextTime + 1
                                      ; restore the same stack twice
-         ldx   #$F1
--        lda   STACKBASE - $EF,x     ; restore stack
+         ldx   #-gStackSize
+-        lda   STACKBASE - $FE + gStackSize,x
+                                     ; restore stack
          sta   $100,x
          inx
          bne   -
@@ -179,7 +180,7 @@ COPYSRC = *
          !source "src/glue.launch.lc2.a"
          !source "src/hw.accel.lc2.a"
   STACKBASE = *
-  LCRAM2_END = STACKBASE + 15
+  LCRAM2_END = STACKBASE + gStackSize
   !if LCRAM2_END >= DisableAccelerator {
     !error "code is too large: ends at ", LCRAM2_END
   }

src/constants.a

@@ -17,7 +17,7 @@
 ; D000..D3FF - ProRWTS data
 ; D400..D6C3 - ProRWTS code
 ; D6C4..DB91 - HGR font code & ProRWTS glue code
-; DB92..DBA1 - backup of stack (during gameplay and self-running demos)
+; DB92..DB98 - backup of stack (during gameplay and self-running demos)
 ; ...unused...
 ; DBB4..DBFF - (de)acceleration function
 ; DC00..DFFF - HGR font data
@@ -104,6 +104,7 @@ BestMatchScore = $FC      ; byte
 ;              $FF        ; used by ParseGamesList
 
 ; main memory
+gStackSize   = 6          ; seems like only six are needed
 gPathname    = $BFD0      ; used by SetPath/AddToPath
 gKeyLen      = $1F00      ; used by ParseGamesList
 gKey         = $1F01

src/glue.launch.lc2.a

@@ -8,9 +8,10 @@
 ; which handle bank switching for you.
 
 LaunchInternal
-         ldy   #$F1
+         ldy   #-gStackSize
 -        lda   $100,y
-         sta   STACKBASE - $EF,y               ; back up stack
+         sta   STACKBASE - $FE + gStackSize,y
+                                     ; back up stack
          iny
          bne   -
          tsx                         ; back up stack pointer