diff --git a/src/devices/bus/vcs/dpcplus.c b/src/devices/bus/vcs/dpcplus.c
index 556584c634e..64c274e31c3 100644
--- a/src/devices/bus/vcs/dpcplus.c
+++ b/src/devices/bus/vcs/dpcplus.c
@@ -4,7 +4,23 @@
 
 Atari 2600 cart with DPC+
 
-the DPC+ adds an ARM CPU amongst other things
+the DPC+ adds an ARM CPU amongst other things (display improvements, etc.)
+
+map (according to a blogpost on atariage):
+	NOTE: All banks are accessible via $F000
+
+	* ARM RAM mapped at $40000000 in this area
+	$0000-$0BFF: DPC+ driver (not accessible by 2600 itself)
+	$0C00-$1BFF: Bank 0
+	$1C00-$2BFF: Bank 1
+	$2C00-$3BFF: Bank 2
+	$3C00-$4BFF: Bank 3
+	$4C00-$5BFF: Bank 4
+	$5C00-$6BFF: Bank 5
+	* ARM RAM mapped at $40000C00 in this area
+	$6C00-$7BFF: Display Data (indirect access)
+	* ARM RAM mapped at $40001C00 in this area
+	$7C00-$7FFF: Frequency Data (not accessible by 2600 itself)
 
 ***************************************************************************/
 
@@ -41,12 +57,13 @@ void a26_rom_dpcplus_device::device_reset()
 }
 
 static ADDRESS_MAP_START( dpcplus_arm7_map, AS_PROGRAM, 32, a26_rom_dpcplus_device )
-	AM_RANGE(0x00000000, 0x00003fff) AM_RAM
+	// todo: implement all this correctly
+	//AM_RANGE(0x00000000, 0x00007fff) AM_ROM // flash, 32k
+	AM_RANGE(0x40000000, 0x40001fff) AM_RAM // sram, 8k
 ADDRESS_MAP_END
 
-
 static MACHINE_CONFIG_FRAGMENT( a26_dpcplus )
-	MCFG_CPU_ADD("arm", ARM7, 20000000)    // ? type ? speed
+	MCFG_CPU_ADD("arm", ARM7, 70000000)    // correct type?
 	MCFG_CPU_PROGRAM_MAP(dpcplus_arm7_map)
 MACHINE_CONFIG_END