bugfix: broke some non-bankset bankswitched games with graphics at start of bank

Author: msaarna

includes/7800basicfooter.asm

@@ -12,6 +12,11 @@
     endif
   endif
 
+  if START_OF_ROM = .
+      .byte 0
+  endif
+START_OF_ROM SET 0
+
   ; FF7E/FF7F contains the 7800basic crc checksum word
 
   ; FF80 - FFF7 contains the 7800 encryption key 

includes/7800basicheader.asm

@@ -120,4 +120,4 @@ BANK_WAS_SET SET 1
    ORG $8000,0 ; default is 32K
  endif
 
-START_OF_ROM = .
+START_OF_ROM SET .

samples/banksets/banksetrom.bin

@@ -923,6 +923,7 @@ void bank(char **statement)
     orgprintf(" if START_OF_ROM = . ; avoid dasm empty start-rom truncation.\n");
     orgprintf("     .byte 0\n");
     orgprintf(" endif\n");
+    orgprintf("START_OF_ROM SET 0 ; scuttle so we always fail subsequent banks\n");
 
     // 2.issue ORG,RORG
     currentbank = requestedbank;
@@ -4422,6 +4423,7 @@ void barf_graphic_file(void)
         orgprintf(" if START_OF_ROM = . ; avoid dasm empty start-rom truncation.\n");
         orgprintf("     .byte 0\n");
         orgprintf(" endif\n");
+        orgprintf("START_OF_ROM SET 0 ; scuttle so we always fail subsequent banks\n");
 	for (currentplain = 0; currentplain <= dmaplain; currentplain++)
 	{
 	    if (bankcount == 0)