fix randomly corrupted DHGR

src/4cade.a

@@ -45,7 +45,6 @@ Reenter
          jsr   DisableAccelerator    ; back to 1 MHz (especially important on IIgs
                                      ; which restores default speed on Ctrl-Reset)
          jsr   CloseHandles          ; close any open handles to restore ProRWTS
-         jsr   SaveOrRestoreScreenHoles ; restore original screen hole contents
          ldx   #5
 -        lda   ResetVector,x         ; copy reentry wrapper to bottom of stack
          sta   $100,x                ; (used as reset vector because ][+ always
@@ -132,10 +131,10 @@ SwitchToBank2
 ;      7 6 5 4 3 2 1 0
 ;      | | | | | | | +- bit 0 reserved
 ;      | | | | | | +--- bit 1 reserved
-;      | | | | | +----- bit 2 = 1 if cheats are enabled
-;      | | | | +------- bit 3 = 1 if IIc
-;      | | | +--------- bit 4 = 1 if IIgs
-;      | | +----------- bit 5 = 1 if VidHD
+;      | | | | | +----- bit 2 reserved
+;      | | | | +------- bit 3 reserved
+;      | | | +--------- bit 4 = 1 if cheats are enabled
+;      | | +----------- bit 5 = 1 if VidHD or IIgs
 ;      | +------------- bit 6 = 1 if 128K
 ;      +--------------- bit 7 = 1 if joystick
 ; Use the bit masks defined in constants.a
@@ -194,7 +193,7 @@ EvenLasterMover
   !ifdef PASS2 {
   } else { ;PASS2
     !set PASS2=1
-    !warn "ProRWTS ends at ", hddcodeend - 1
+    !warn "ProRWTS ends at ", hdddataend - 1
     !warn "STACK at ", STACKBASE
     !warn "LCRAM2 ends at ", LCRAM2_END - 1
     !warn "RELBASE = ", $10000 - (LastMover - FirstMover)

src/4cade.init.a

@@ -30,34 +30,26 @@
 +
          lda   #0
          sta   zpMachineStatus
-         lda   ROM_MACHINEID
-         cmp   #$06
-         bne   @NotIIc
-         lda   $FBC0
-         beq   @IsIIc
-@NotIIc  clc
-@IsIIc   ror   zpMachineStatus
-         sec
-         jsr   $FE1F                 ; check for IIgs (allows super hi-res artwork)
-         bcs   NotGS
-         jsr   ROM_TEXT2COPY         ; set alternate display mode on IIgs (required for some games)
-+        sec
-         +HIDE_NEXT_BYTE
-NotGS    clc
-         ror   zpMachineStatus
          sta   SETC3ROM
          jsr   HasVidHDCard          ; check for VidHD card (allows super hi-res artwork even on non-IIgs machines)
-         ror   zpMachineStatus
          sta   CLRC3ROM
-         jsr   Has128K               ; check for 128K (allows DHGR slideshows and 128K games)
+         ror   zpMachineStatus
+         lda   ROM_MACHINEID
+         cmp   #$06
+         bne   @NotGS
+         sec
+         jsr   $FE1F                 ; check for IIgs (allows super hi-res artwork)
+         bcs   @NotGS
+         jsr   ROM_TEXT2COPY         ; set alternate display mode on IIgs (required for some games)
+         lda   #$80
+         sta   zpMachineStatus
+@NotGS   jsr   Has128K               ; check for 128K (allows DHGR slideshows and 128K games)
          ror   zpMachineStatus
          jsr   HasJoystick           ; check for joystick (absence is OK but we filter out some games that require a joystick)
-         ror   zpMachineStatus       ; now bit 3 = 1 if IIc
-                                     ;     bit 4 = 1 if IIgs
-                                     ;     bit 5 = 1 if VidHD
+         ror   zpMachineStatus       ; now bit 5 = 1 if VidHD or IIgs
                                      ;     bit 6 = 1 if 128K
                                      ;     bit 7 = 1 if joystick
-                                     ; and all other bits are 0 (we'll set bit 2 after copying it to LC RAM)
+                                     ; and all other bits are 0 (we'll set bit 4 after copying it to LC RAM)
 
          lda   ROM_MACHINEID
          cmp   #$06
@@ -241,9 +233,6 @@ PrintAsDecimal
 OneTimeSetup
          lda   zpMachineStatus
          sta   MachineStatus         ; save machine status in LC RAM
-         jsr   SaveOrRestoreScreenHoles ; save initial copy of screen hole content
-         lda   #$91
-         sta   holepatch             ; enable restoring of copy from now on
          ldy   #$0b
 CopyDevs
          lda   $BF13,y

src/constants.a

@@ -9,14 +9,14 @@
 ; D000..E611 - persistent data structures (per-game cheat categories,
 ;              gGlobalPrefsStore, gGamesListStore)
 ; ...unused...
-; ECC8..FFF9 - main program code
+; ECC6..FFF9 - main program code
 ; FFFA..FFFF - NMI, reset, IRQ vectors
 ;
 ; LC RAM BANK 2
 ; D000..D3FF - ProRWTS data
-; D400..D5F7 - ProRWTS code
-; D5F8..DB52 - HGR font code & ProRWTS glue code
-; DB53..DB6E - backup of stack (during gameplay and self-running demos)
+; D400..D671 - ProRWTS code
+; D672..DB6D - HGR font code & ProRWTS glue code
+; DB6E..DB7D - backup of stack (during gameplay and self-running demos)
 ; ...unused...
 ; DBB6..DBFF - (de)acceleration function
 ; DC00..DFFF - HGR font data
@@ -116,6 +116,5 @@ DisableAccelerator = $DBB6
 EnableAccelerator  = DisableAccelerator+3
 
 ; AND masks for MachineStatus
-SUPPORTS_SHR   = %00110000
-IS_IIC         = %00001000
-CHEATS_ENABLED = %00000100
+SUPPORTS_SHR   = %00100000
+CHEATS_ENABLED = %00010000

src/fx/hw.vbl.a

@@ -16,12 +16,10 @@ WaitForVBL
          pha
          +READ_ROM_NO_WRITE
          lda   $FBB3
-         +READ_RAM1_WRITE_RAM1
          cmp   #$06
          bne   @nop
-         lda   MachineStatus
-         and   #IS_IIC
-         bne   @iic
+         lda   $FBC0
+         beq   @iic
          +LDADDR WaitForVBL_iie
          bne   +
 @iic
@@ -38,6 +36,7 @@ WaitForVBL
          lda   #$4C       ; JMP opcode
          sta   WaitForVBL
 
+         +READ_RAM1_WRITE_RAM1
          pla
          tay
          pla
@@ -71,5 +70,4 @@ UnwaitForVBL
          sta   $C07F      ; enable access to VBL register
          sta   $C05A      ; enable VBL polling
          sta   $C07E      ; disable access to VBL register
-         cli
          rts

src/glue.launch.lc2.a

@@ -8,7 +8,6 @@
 ; which handle bank switching for you.
 
 LaunchInternal
-         jsr   SaveOrRestoreScreenHoles ; save screen hole contents
          ldy   #$F1
 -        lda   $100,y
          sta   STACKBASE - $F0,y               ; back up stack

src/prodos.impl.lc2.a

@@ -528,42 +528,3 @@ ProDOS_prefix=gPathname
 ;       !fill $2e
 }
 end_promote
-
-
-;------------------------------------------------------------------------------
-; SaveOrRestoreScreenHoles
-; preserve screen hole contents across demo execution
-; to avoid crashing later on disk access
-;
-; in:    nothing
-; out:   all flags clobbered
-;        all registers clobbered
-;------------------------------------------------------------------------------
-
-SaveOrRestoreScreenHoles
-         lda   #4
-         sta   namhi
-         ldx   #0
-         stx   namlo
-         sta   bloklo
---       ldy   #$78
--        lda   (namlo),y
-         pha
-         lda   holey_stuff,x
-holepatch ;sta->lda
-         lda   (namlo),y
-         pla
-         sta   holey_stuff,x
-         inx
-         tya
-         eor   #$80
-         tay
-         bmi   -
-         iny
-         bpl   -
-         inc   namhi
-         dec   bloklo
-         bne   --
-         rts
-holey_stuff
-         !fill 64