added ZP shadowing for monitor and Z80 CPU emulator

src/aliases/,aliases_ram_lowmem.s

@@ -153,7 +153,7 @@
 	!addr KEYTAB    = $F5  ; $F5-$F6  pointer to keyboard lookup table
 	!addr RIBUF     = $F7  ; $F7-$F8  -- WIP -- RS-232 receive buffer pointer
 	!addr ROBUF     = $F9  ; $F9-$FA  -- WIP -- RS-232 send buffer pointer
-	;                 $FB     $FB-$FE  -- UNUSED --          free for user software
+	;                 $FB    $FB-$FE  -- UNUSED --          free for user software
 	!addr BASZPT    = $FF  ;          -- NOT IMPLEMENTED --
 
 	;

src/aliases/,aliases_ram_over64K_m65.s

@@ -20,5 +20,12 @@
 	;                (2KB) - color RAM mirror, not useable
 	; $20000-$2FFFF (64KB) - ROM, the essential part
 	; $30000-$4FFFF (64KB) - ROM, additions
-	; $50000-$57FFF (32KB) - reserved for graphics screen
+	; $50000-$57F71 (32KB) - reserved for graphics screen
+	; $57F72-$57FFF        - shadow location for BASIC zeropage
+
+!set MEMCONF_SHADOW_BZP_0 = $72
+!set MEMCONF_SHADOW_BZP_1 = $7F
+!set MEMCONF_SHADOW_BZP_2 = $05
+!set MEMCONF_SHADOW_BZP_3 = $00
+
 	; $58000-...           - extended BASIC variables, RAM disk, etc.