diff --git a/src/mame/drivers/astrocde.c b/src/mame/drivers/astrocde.c
index 6cbc7997eea..0ccc16027c2 100644
--- a/src/mame/drivers/astrocde.c
+++ b/src/mame/drivers/astrocde.c
@@ -417,6 +417,9 @@ static WRITE8_HANDLER( profpac_banksw_w )
 {
 	int bank = (data >> 5) & 3;
 
+	/* this is accessed from I/O space but modifies program space, so we normalize here */
+	space = cpu_get_address_space(space->cpu, ADDRESS_SPACE_PROGRAM);
+
 	/* remember the banking bits for save state support */
 	profpac_bank = data;
 
@@ -448,7 +451,7 @@ static WRITE8_HANDLER( profpac_banksw_w )
 
 static STATE_POSTLOAD( profbank_banksw_restore )
 {
-	const address_space *space = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_PROGRAM);
+	const address_space *space = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO);
 
 	profpac_banksw_w(space, 0, profpac_bank);
 }
@@ -1720,13 +1723,14 @@ static DRIVER_INIT( robby )
 static DRIVER_INIT( profpac )
 {
 	const address_space *space = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_PROGRAM);
+	const address_space *iospace = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO);
 
 	astrocade_video_config = AC_SOUND_PRESENT;
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x14, 0x14, 0x0fff, 0xff00, profpac_io_1_r);
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x15, 0x15, 0x77ff, 0xff00, profpac_io_2_r);
+	memory_install_read8_handler(iospace, 0x14, 0x14, 0x0fff, 0xff00, profpac_io_1_r);
+	memory_install_read8_handler(iospace, 0x15, 0x15, 0x77ff, 0xff00, profpac_io_2_r);
 
 	/* reset banking */
-	profpac_banksw_w(space, 0, 0);
+	profpac_banksw_w(iospace, 0, 0);
 	state_save_register_postload(machine, profbank_banksw_restore, NULL);
 }
 
@@ -1734,15 +1738,16 @@ static DRIVER_INIT( profpac )
 static DRIVER_INIT( demndrgn )
 {
 	const address_space *space = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_PROGRAM);
+	const address_space *iospace = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO);
 
 	astrocade_video_config = 0x00;
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x14, 0x14, 0x1fff, 0xff00, demndrgn_io_r);
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x1c, 0x1c, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "FIREX"));
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x1d, 0x1d, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "FIREY"));
-	memory_install_write8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x97, 0x97, 0x0000, 0xff00, demndrgn_sound_w);
+	memory_install_read8_handler(iospace, 0x14, 0x14, 0x1fff, 0xff00, demndrgn_io_r);
+	memory_install_read8_handler(iospace, 0x1c, 0x1c, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "FIREX"));
+	memory_install_read8_handler(iospace, 0x1d, 0x1d, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "FIREY"));
+	memory_install_write8_handler(iospace, 0x97, 0x97, 0x0000, 0xff00, demndrgn_sound_w);
 
 	/* reset banking */
-	profpac_banksw_w(space, 0, 0);
+	profpac_banksw_w(iospace, 0, 0);
 	state_save_register_postload(machine, profbank_banksw_restore, NULL);
 }
 
@@ -1750,20 +1755,21 @@ static DRIVER_INIT( demndrgn )
 static DRIVER_INIT( tenpindx )
 {
 	const address_space *space = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_PROGRAM);
+	const address_space *iospace = cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO);
 
 	astrocade_video_config = 0x00;
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x60, 0x60, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P60"));
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x61, 0x61, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P61"));
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x62, 0x62, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P62"));
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x63, 0x63, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P63"));
-	memory_install_read8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x64, 0x64, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P64"));
-	memory_install_write8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x65, 0x66, 0x0000, 0xff00, tenpindx_lamp_w);
-	memory_install_write8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x67, 0x67, 0x0000, 0xff00, tenpindx_counter_w);
-	memory_install_write8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x68, 0x68, 0x0000, 0xff00, tenpindx_lights_w);
-	memory_install_write8_handler(cpu_get_address_space(machine->cpu[0], ADDRESS_SPACE_IO), 0x97, 0x97, 0x0000, 0xff00, tenpindx_sound_w);
+	memory_install_read8_handler(iospace, 0x60, 0x60, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P60"));
+	memory_install_read8_handler(iospace, 0x61, 0x61, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P61"));
+	memory_install_read8_handler(iospace, 0x62, 0x62, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P62"));
+	memory_install_read8_handler(iospace, 0x63, 0x63, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P63"));
+	memory_install_read8_handler(iospace, 0x64, 0x64, 0x0000, 0xff00, input_port_read_handler8(machine->portconfig, "P64"));
+	memory_install_write8_handler(iospace, 0x65, 0x66, 0x0000, 0xff00, tenpindx_lamp_w);
+	memory_install_write8_handler(iospace, 0x67, 0x67, 0x0000, 0xff00, tenpindx_counter_w);
+	memory_install_write8_handler(iospace, 0x68, 0x68, 0x0000, 0xff00, tenpindx_lights_w);
+	memory_install_write8_handler(iospace, 0x97, 0x97, 0x0000, 0xff00, tenpindx_sound_w);
 
 	/* reset banking */
-	profpac_banksw_w(space, 0, 0);
+	profpac_banksw_w(iospace, 0, 0);
 	state_save_register_postload(machine, profbank_banksw_restore, NULL);
 }